Protect Plants from Winter Problems

Now that November is here, we can begin to prepare our plants for the winter conditions. Some of those preparations are to get plants ready for cold weather and some are to protect them from wildlife.

My beautiful picture

Wildlife Damage

During the winter months we can see plant damage from deer, rabbits, and voles. Deer can chew off the ends of small twigs and bucks can rub their antlers on the trunk of smaller trees. Rabbits can also chew on smaller plants, sometimes chewing small plants off at ground level. Rabbits and voles can also gnaw on the thin bark of our young trees to feed on the green, inner bark areas. There is no cure once it happens, so it is best to protect our plants prior to damage.

Rabbit Protection, Lancaster Co. Ext

Rabbit Protection Fence, Photo from Lancaster County Extension

Exclusion is the best defense but is sometimes a difficult task. There are fences that can be utilized but they need to be at least 8 feet tall for deer damage. Rabbits can be managed with a fence that is 2 feet tall. Voles can be controlled by removing tall grass and weeds from around the trunk of trees and by avoiding mulch layers deeper than three inches around trees. Placing hardware cloth around tree trunks will also prevent vole feeding. The commercial spray repellants available for deer or rabbits are not very effective and would need to be reapplied often.

Winter Mulch

Winter mulch can be applied now, or within a few weeks when temperatures are consistently dropping down to the twenties each night. Winter mulch is the heavier layer of mulch we apply to herbaceous perennial plants and strawberries to keep them from having temperature fluxes throughout the winter. Any plant that may be prone to frost heaving, the plant being pushed up out of the soil by a constant freeze and thaw condition, or plants that were just planted this fall could also benefit from winter mulching. This mulch can be up to four inches deep, which is deeper than we usually advise but is needed for winter protection. It is better to use coarse wood chips or leaves for winter mulch rather than grass.

Winter Watering

Winter watering is essential in dry winter years. Winter desiccation commonly occurs on evergreen types of trees and shrubs. All trees are still transpiring, or losing water, throughout the winter months, evergreen trees are transpiring at a higher rate than deciduous trees. Winter desiccation occurs when the amount of water lost is greater than the amount of water the evergreen takes in throughout the winter months. The damage from winter desiccation is brown needles out on the ends of branches. However, the damage from winter desiccation will not usually show up in our trees until early spring, so they will stay green through the winter. Drought effects can damage deciduous trees as well. Especially newly planted deciduous trees. All of our trees may need to be watered throughout the winter months if natural precipitation or snow cover is absent.

Winter watering should occur during the day on days when the temperature is 40 degrees Fahrenheit or above and is only necessary 1-2 times per month until spring. It is a good idea to test for soil moisture with a long screwdriver or soil probe prior to watering to determine if watering is necessary. If the screwdriver goes into the soil easily up to 18 inches, watering is not necessary. However, if pushing the screwdriver into the soil is very difficult, watering would be necessary.

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Trees turn color in fall

Fall tree color blog

Fall is a great time of the year. The trees start turning colors and everything looks so beautiful, even the green conifer trees. Evergreen trees should maintain their green color all of the time, right? This time of the year I get many calls on a natural process of evergreen trees called Natural Needle Drop.

Natural Needle Drop

Natural Needle Drop

White Pine with Natural Needle Drop

Evergreen trees turning yellow in the fall may not be a problem, in fact it may be completely natural. Evergreen trees do hold onto their needles, but eventually the older needles are shed from the tree in the fall. When this happens, those needles turn yellow before they fall from the tree. As long as the needles that turn yellow are all on the interior of the tree, there is no real concern. The older needles are the needles that are shed, which will be held on the interior of the tree, not on the ends of the branches.

Natural needle drop is very noticeable on white pine trees because they are naturally not a dense tree and they lose their needles every 2 years, making it quite common. Ponderosa pines lose their needles every 3 years, while Austrian pines lose their needles every 4 years. It is not as common to notice the needle drop on these trees due to the infrequency as well as the density of the tree. Spruce trees will also lose their needles, but much less often. Spruce trees will typically hold onto the majority of their needles for up to 10 years

Deciduous Conifers

It is important to know what you tree is supposed to do in the fall and winter months. We have a couple of trees that are classified as ‘Deciduous Conifers’ meaning that they are a conifer due to their needles and how they are arranged but are deciduous because they lose those needles annually. Two deciduous conifers are commonly found in Nebraska, the Larch and Baldcypress. These trees will lose all of their needles in the fall after first turning brown throughout the entire tree. If you don’t know what type of tree you have in your yard or are not familiar with the growth habit of these trees, you might think they died, when they are really just going through their normal lifecycle.

Fall Color for Deciduous Trees

20181023_152033Speaking of deciduous trees, this is the time of the year when our deciduous trees, those with leaves rather than needles, will change color and the leaves will fall from the tree. As the nights gets cooler and the days get shorter, the tree produces a membrane between the branches and the leaves which causes the leaves to be shed from the tree. Prior to leaf drop, this membrane also causes cessation of chlorophyll from the leaves for the year. At this time, the other pigments are allowed to show up in the leaves.

The brightest fall colors are produced when dry, sunny days are followed by cool, dry nights. The dry, sunny days are needed to break-down the chlorophyll in the leaves allowing the other pigments to be dominant in the leaves. The cool, dry nights are also necessary for fall color because trees need to avoid freezing temperatures which can injure or kill the leaves causing them to stop producing much sugar at all. The sugar content is what increases the amount of the anthocyanin, or red pigment.

Pumpkins, Spiders, and Mums

Halloween Pumpkins

Now that October is here, we begin to get prepared for Halloween, a day which I personally enjoy. Pumpkins, spiders, and fall flowers are all part of this festival. So, I won’t miss the chance to help you with your holiday decorations and traditions.

Pumpkins

2017-10-28 19.10.50Pumpkins can be used for so many things including carving, decoration, pies, and many other food products. If planted later in the summer growing season, your pumpkins should just be maturing, or have matured within the last couple of weeks. If you are unsure, pumpkins are mature when the rind is hard and can resist penetration from a fingernail.

Pumpkins do need to be harvested prior to a hard frost. They can be ok out on the vine for a light frost, but a hard frost will damage the pumpkin and can damage storage potential and more likely cause the pumpkins to rot. They should be cut off the vine. Do not cut the vine too close to the pumpkin, this can also cause the pumpkin to decay sooner.

If you didn’t grow the pumpkin yourself, check over the pumpkins you are purchasing. Look for good rind with no puncture wounds. Ensure that the pumpkin has a bit of stem attached to the top and choose the correct pumpkin for the use you have in mind for it. Pie pumpkins are best for baking while jack-o-lantern types will be better for carving and for decorations.

Spiders

Wolf Spider, UNL ENTO

Wolf Spider photo by Jim Kalisch, UNL Entomology

Spiders always come to mind at Halloween as a decoration and because they become a problem inside our homes with the cool fall weather. The most common spider that people bring into my office to be identified is the wolf spider. These are one of the largest species of spiders that we will find in Nebraska. They are quite hairy and often times will have 2 white or lighter brown colored stripes down the back of the spider. There are some wolf spiders that can be the size of a half dollar or more, legs and all. These spiders are not poisonous, but they can bite. Most often, a wolf spider will not bite us, but if they do the reaction is usually similar to a large mosquito bite.

Spiders are actually beneficial, but not often desired. They feed on other insects and pests that can move into our homes. The best way to control a spider population indoors is through habitat modification, meaning to seal up all cracks and crevices in your home foundation and around windows and doors to ensure that the spiders don’t move into your home. You can also use the indoor/outdoor barrier sprays to spray around the foundation of your home and around the windows and doors to reduce spider populations inside your home. Also, sticky traps are a great way to manage spider populations indoors. 

Mums

orange mum, pixabay

Mums are not the scary holiday tradition that spiders and pumpkins are, but they are a common decoration for the fall, including Halloween. Garden mums grow up to 18 inches tall and 30 inches wide and grow into a clump. The flowers are 2-3 inches across and can be found in many colors including white, yellow, orange, pink, purple, coral, and deep burgundy red depending on the variety. Mums need to be pinched back in the early summer to help keep the plants to a compact and uniform size and shape and to help flowering. Pinching should be done 2-3 times in June. It should begin when the plants are 5-6 inches high and it should be discontinued around the 4th of July.

Many gardeners struggle with maintaining their mum plants over the winter due to repeated freezing and thawing cycles through the growing season as well as wet, heavy soil or lack or snow cover. Longevity of the plants can be enhanced by planting them in a location that is more protected from north winds, discontinuing fertilization by the end of July to reduce new growth at the end of the season, adding several inches of mulch to the soil around the plants through the winter months, and cutting the plants back in the spring rather than in the fall.

Biting Insects

Shagbark hickory, flickr, Nicholas A. Tonelli

Now that Fall is officially here, the weather is starting to cool down and we can venture outdoors more. Activities such as Hiking, harvesting, hunting, football, and just enjoying the cooler weather on your patio in the evening are all pleasant outdoor activities this time of the year. However, when we venture outdoors, our plan is never to be the menu for all the pesky insects outdoors.

Mosquitoes

mosquitoMosquitoes are out in full force right now. After the rains we have seen over the past couple of weeks, their population has exploded. Mosquitoes can transmit many diseases, so it is best to protect yourself when you are outdoors. Use Insect repellent and wear long sleeves and long pants or permethrin-treated clothing when outdoors between dusk and dawn when mosquitoes are most prevalent.

As far as chemical control, Mosquito Dunks contain the active ingredient bacterium, Bacillus thurengiensis israelensis (Bti), which is toxic to mosquito larvae when consumed, but non-toxic to humans, pets, pollinators, fish, and other wildlife. They are sold in hardware stores, and will dissolve in standing water such as water troughs, fishponds, rain barrels, and birdbaths. They are effective immediately and can last for a month. For homeowners, it is not recommend to use foggers or adulticide treatments. These treatments are not effective for more than a couple of days and should only be used a few days ahead of a large outdoor get-together if absolutely necessary. At this point, it would be best to just wait for a frost to kill off the majority of our mosquitoes. Our average first frost date is the end of September to the beginning of October, so one should be here soon.

Minute Pirate Bugs

minute-pirate-bug-zoomed-kim-riggs-richardson-co

Minute Pirate Bug

Minute pirate bugs are also a nuisance right now as well. Minute pirate bugs are the tiny, black insects that seem to fall out of the trees and bite us during the fall months. The bug, which is a true bug, is 1/8 inch in length black insect with white and black wings. The appearance of this bug is very similar to a chinch bug. The wings have an “X” on them which is typical for insects that are true bugs.

Minute pirate bugs are present throughout the summer but they are out in fields, woodlands, and gardens. During the summer they are feeding on other insects, making them a beneficial insect. But, in the fall, these insects move into the areas where people are more often outside and they begin to bite us. When they bite us, they insert their piercing-sucking mouthpart into our skin, which can be painful. Some people may react differently and swell up from the bite, but most people just have the initial pain with the bite. Minute Pirate bugs do NOT feed on blood, inject a venom or transmit diseases. Control is not practical for them as they will also die with our first frost. Insect repellents do not deter them, so it is best just to wear long pants and a long-sleeved shirt to reduce areas for them to bite us.

Ticks

lonestar tick, lifestages, J. Kalisch

Lonestar tick life stages, Photo from Jim Kalisch and Wayne Kramer UNL Department of Entomology

Ticks are also still a problem this late into the season. Ticks are common in wooded areas or in tall grass. If outdoors in areas where ticks are commonly found, wear light-colored, long-sleeved shirts and long pants and closed toe shoes to reduce exposed areas where ticks can attach to your skin. Also, use insect repellents any time you are outdoors, the repellents with DEET have the highest efficacy. One tick I have seen recently is the immature form of the Lonestar Tick. This immature form is very tiny in size and would be easily missed by a quick visual inspection. This tick can spread diseases if left to feed on you long-term, so be sure to protect yourself prior to going outdoors and check yourself when you come indoors.

Battling Weeds in the Lawn

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September is a time for the lawn. In my last article, I discussed overseeding and fertilizing the lawn, but weed control is another key to a healthy lawn. Some weeds in the lawn are often tolerated, but when the weed population begins to outweigh the turf population, management should be incorporated.

The Battle with Weeds

Plants are considered weeds because they are adaptive, aggressive and opportunistic. Weeds come into a lawn that is thin or bare. They are often found on the edges of our lawn or places where the grass doesn’t grow as well. Eventually they will work their way into the rest of our lawn. So overseeding a lawn may be the answer to reducing the weed population.

Growing turfgrass in the shade is not always possible. Even the shade mixes are not made to grow in high shade. Dense shade is not the growing condition for turfgrass and it often leads to weeds. In some cases, trees may be pruned to improve the sunlight getting to the turf, but be careful not to ruin the shape or health of a tree or shrub  just to get more sunlight to the turf. If the shade is too dense, a good alternative might be a shade tolerant groundcover or apply mulch where grass won’t grow.

Crabgrass

Crabgrass has been found in high populations this year, even in locations where crabgrass preventer was used. The University of Nebraska-Lincoln Turf department says the weather is to blame. Crabgrass germinates when soil temperatures reach 57-64 degrees at a one-inch depth, with the highest germination when soil temperatures increase to 73 degrees. Crabgrass will continue to germinate through the summer until soil temperatures reach 95 degrees. With the unusual weather we had this spring and summer, the largest amount of crabgrass germinated later than normal when the concentration of our original spring crabgrass pre-emergence herbicide was declining. This is why we saw so much more crabgrass later this summer than we usually do.

To help prevent this problem with later emerging crabgrass in the future, switch to longer lasting chemicals, such as prodiamine. You can also look to a second application of crabgrass preventer in mid-June to stop the germination of the late flush of crabgrass. There are also post-emergent herbicides to use for crabgrass, but I don’t recommend them this late in the season. Remember, crabgrass you are seeing now will die when the first frost hits. Also, it is difficult to kill a large crabgrass plant with a post-emergent herbicide.

Broadleaf Weed Control

As for when to treat for broadleaf weeds that do come into our lawns, fall is the best time to control them. In fall, perennial weeds are moving carbohydrates from the leaves into the roots for winter storage to help get them going again next spring. If you spray them in the fall, the herbicide will also be moved into the roots which makes the herbicide more effective. Also, the weather is more suitable for herbicide use than in the spring when Dicamba and 2,4-D have a potential to drift to non-target plants. Fall is also a great time to apply herbicides to kill the winter annual weeds such as Henbit either with a pre-emergent herbicide such as prodiamine (Barricade) or dithiopyr (Dimension) or with a post emergent after the henbit has germinated.

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Henbit along a sidewalk edge

The best time to apply herbicides in the fall is mid-late September and again in mid-late October. The second application helps to get better control on perennial weeds that may have been missed or were not fully killed. The second application also helps to ensure that winter annuals have germinated to help get control of those with a post-emergent herbicide. Products containing 2,4-D, carfentrazone, sulfentrazone, quinclorac, or triclopyr are all good for controlling perennial weeds in the lawn. Use caution around trees, shrubs, and landscape beds as these products can damage broadleaf plants but they will not harm our turf.

Fall Lawncare

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Bare lawn in need of overseeding.

There are a lot of activities for us to do in the fall in our lawns to help our plants make it through winter and to improve their growth for next year. I wanted to take time to cover some of those items on your fall lawncare “to do” list.

It is now time to reseed or overseed your lawns for the fall. This is best done in the late summer or early fall, anytime between late August and the end of September. The rule of thumb is that that for each week grasses are seeded before Labor Day, maturation is speeded by two weeks. If you reseed after September 15 you could still be successful, but you increase your risk of dieback on newly emerged young seedlings in the event of an early frost. If you are a homeowner who wants to sod an area of your lawn, you can do that until they can no longer cut it from the fields.

Overseed with the same type of lawn that is already existing or a mix of Kentucky bluegrass and tall fescue. When starting a new lawn, either of these would be good choices. Avoid mixes that contain annual ryegrass, ‘Linn’ perennial ryegrass, or ‘Kenblue’ Kentucky Bluegrass. Make sure that the grass you buy contains less than 0.3 percent weed seed and No noxious weed seeds. If you prefer, you could also plant Buffalograss in your lawn, but this should be done in June and July.

sprinkler-pixabay

Lawn Sprinkler Photo Courtesy of Creative Commons License

When establishing new turf, use frequent, light watering practices to get the seed to germinate. Don’t let the seed dry out and don’t let it get too soggy either. As the grass grows, decrease the frequency of watering, but increase the amount of water applied. Don’t drastically change watering practices from newly seeded to established turf watering practices. Don’t apply any herbicides to newly seeded turf until after mowing 3 times on the new turf.

As for fertilizer applications, the fall fertilization is the most important fertilizer application for a lawn. However, fall fertilization recommendations have changed over the past couple of years. For a lawn, a Labor Day to mid-September application of slow release fertilizer is still recommended. Apply a granule with 50% slow release nitrogen or less. If additional nitrogen fertilizer is required later in the fall, use a product with a quick release nitrogen before mid-to late October. We used to recommend Halloween or later for the second fertilizer application and we thought two applications were necessary. New research is showing us that a second application of nitrogen fertilizer may not even be necessary, but if it is, we should move the timing up to more like Columbus Day rather than the typical Halloween time frame. This information is from Bill Kreuser, Assistant Professor and Turfgrass Extension Specialist from the University of Nebraska-Lincoln.

Mowing is always on our minds this time of year as well. Continue mowing through the fall as long as the grass is growing and needs to be mowed. You don’t want to leave long grass blades through the winter as this can smother the grass and lead to snow mold. Also, be sure to rake up leaves that fall on the lawn through the fall as this can also lead to snow mold. You can mow over the leaves with a mulching blade rather than rake them if you prefer.

 

Yard and Garden: August 3, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for August 3, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am this was the final episode for 2018. It can be found again next spring on kutt995.com for online listening. If you enjoy reading my Q&A from the show each week, take my quick survey at: go.unl.edu/yardandgarden18 and be entered to win a free tree diagnostic book.

Guest Hosts: Kevin Christiansen, Horticulture Instructor at SCC Beatrice & Evan Alderman, Turfgrass Management and Horticulture Instructor at SCC Beatrice

1. The first caller of the day has a windbreak that has elms growing in it. How can he kill the elms and not harm the windbreak trees?

A. In this situation you need to use a herbicide that will kill the elms but will not be translocated through the roots into the surrounding windbreak trees. Tordon should NOT be used in this location. A good option would be either glyphosate, Roundup, or a 2,4-D product. Use these 2 products as a stump treatment on the tree just after cutting the tree off.

2. A caller has cucumbers that are blooming but are not producing any fruit yet. Why are the cucumber not producing? This caller also wondered how to control puncturevine?

A. The cucumbers could be due to no female flowers, if all the flowers are male, they will not produce any fruits. Sometimes our plants start with just male flowers and the females will come in later. It could also be due to low pollinators around the plants. If not many bees or beetles or other insects are found around the plants, they cannot be pollinated and may need to be hand pollinated. Hand pollination can be done by running a cotton swab through all of the blooms, this would move pollen from male flowers to female flowers. Puncturevine can be controlled with a 2,4-D product in the fall. Apply the 2,4-D in mid-September and in mid-October.

3. When should you transplant surprise lilies?

A. Surprise lillies can be transplanted or divided just after the flower dies back in the fall.

4. This caller has foxtail in the vegetable garden. Can anything be sprayed in the garden to control the foxtail?

A. There is nothing that can be sprayed over a garden to control foxtail and not harm the garden plants. The best option would be to use preen in the spring and summer to stop the germination of annual weeds such as foxtail. Be sure to use the preen that is labeled for use in a vegetable garden and wait until after all seeds planted have germinated. Mulch would help suppress the weeds in the garden as well. Grass clippings, straw, or other organic mulches will help keep the weeds down to help your vegetable plants grow better.

5. A caller was looking for assistance choosing fruit trees for his acreage. He also has rust on his fruit trees and wants to know how to manage it.

A. There is a great NebGuide on Fruit Tree Cultivars for Nebraska. For rust, this is not the correct time to treat for it. You can spray your trees in the spring with a liquid copper fungicide. For more on care and pest control of your fruit trees, visit: https://food.unl.edu/local-food-production

6. This caller has a windbreak of Red Cedars that are losing limbs. The trees are 100 years old and 30 feet tall. What is wrong with them?

A. This could be due to old age. It may be a good idea to start a new row of trees on the inside of the old row.

7. A caller has nutsedge in his lawn. What can he spray it with and can he still spray it?

A. Sedgehammer is the best control for nutsedge. It can still be sprayed now, however more control will be achieved if applied in the beginning of June, prior to the first day of summer. If sprayed before June 21st, nutlet production will be reduced, thereby reducing the population for the following year.

2014-10-06 15.27.18

Tree planting in the fall

8. This caller wants to know when the best time is to transplant an oak tree?

A. Fall or Spring are both good times to transplant a tree.

9. How do you control cattails and water lilies in a pond?

A. Rodeo is the glyphosate product that is labeled for use in water and it can be used on both of these weeds.

10. How can you control crabgrass and nutsedge in a lawn

A. Quinclorac can be used now for both of these weeds. Or use a pre-emergent herbicide in the spring and again in June for the crabgrass and sedgehammer for the nutsedge in June. Tenacity is another product that should work on both of these weeds.

11. A caller wants to know why we should worry about getting rid of cattails and water lilies in a pond?

A. Weeds in a pond can strangle the waterways or destroy habitat for fish. Some plant life along the edge of the pond can be beneficial, but too much can be a detriment.

12. This caller has lilies with caterpillars in the stem. What are those and how can they be destroyed?

A. This is likely a cutworm. Sevin or eight or Bt applied at the base of the plant can help kill these pests before they damage your plants.

13. When is the proper time to apply a winter fertilizer on a lawn?

A. Fall fertilizer can be applied in late August to mid September and the winter fertilizer can be applied in the middle to late October. It is no longer recommended to apply the winter fertilizer in November as previously recommended.

14. A walk-in listener has a weed they need identified and they need to know how to control it?

A. This is a weed called nimblewill. It is a warm-season grassy weed. It can be treated either with Roundup or Tenacity. If you use Roundup and reseed, apply the roundup now, while the nimblewill is still green and then overseed in a couple of weeks through the end of September.

15. This caller has spaghetti squash that was looking great and then one day it just died. What caused it to die and how can the other plants be protected?

A. This is likely due to squash vine borer. You can use sevin or eight to protect your plants from the squash vine borer. Be sure to apply it at the base of the plant where the plant comes out of the ground. These chemicals will need to be reapplied every 10-14 days throughout the growing season to protect the plants. Otherwise, you can wrap the base of the plant in aluminum foil to prevent the borer from getting into the plant.

16. A caller has watermelons with yellowing leaves. This has happened to his plants 3 years in a row now, he does rotate the crops in the garden. This damage starts at the base of the plants and will eventually kill the whole vine. He has mulch on the garden and waters slowly with a hose for 2 hours at a time. What is causing this problem? Also, when do you transplant iris?

A. This looks to be alternaria leaf spot. He is doing many things to prevent this disease already with mulch and his watering practices. It might be beneficial to try a liquid copper fungicide this year and next year as soon as the symptoms begin. Iris can be transplanted in the fall, September or October would be best.

17. A walk-in listener has a tree they want identified and they want to know why it keeps suckering and what they can do with the suckers?

A. This is a silver maple tree, they are prone to suckering. Suckers should be just cut off as they grow to reduce the amount of energy they take from the main tree. Do not treat the suckers with anything as that could injure or kill the main tree because the suckers are growing off the main tree roots.

18. This caller wants to know why their pepper plants are not growing well?

A.The peppers are planted too closely to a black walnut tree and will not grow well in that location. Black walnut trees produce juglone, which is basically a naturally produced weed killer. Certain plants are more sensitive to juglone, tomatoes and peppers are quite sensitive. The garden should be moved to at least 50 feet from the black walnut of the plants should be grown in a container or raised bed to avoid problems with the juglone.

19. The final caller of the year has hostas planted in a rock garden and they are not growing, they are still small like they were just planted there.

A. The rock garden may be too hot for the hostas and the rocks do not provide any nutrients back to the plants. It might be best to switch to a wood chip mulch to help reduce the heat and add some nutrients and organic matter to the soil.

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Bindweed

This caller also wanted to know what to do to kill the bindweed growing in her Iris beds?

A. Among other plants it is best to use the “glove of death” which is when you wear a chemical-resistant glove and then put a cloth glove over that. Then, dip a few fingers of the gloved hand into Glyphosate and rub those fingers along the stem and leaves of the bindweed to kill it. Basically, the idea is to keep it from flowering and producing more seed, hand pulling will help keep new seed from being deposited into the garden which can be viable for up to 60 years.

Yard and Garden: July 27, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for July 27, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 3, 2018. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Steve Karloff, District Forester for the Nebraska Forest Service

1. The first caller of the day has tomatoes that are rotten on the bottom. What is wrong with them and what can be done?

A. This is blossom end rot, it is where the blossom end (or the end of the tomato farthest from the plant) rots. It is due to a calcium deficiency due to uneven watering. The calcium is in the soil, but uneven watering makes it unavailable to the plant. Mulch will help keep the soil at a uniform moisture level to help protect plants from this disorder. Blossom end rot is a short-term problem in our vegetable crops. It tends to only affect the plant for a the first couple of harvests of the year and then the plant grows out of it. You can cut the black end off of the fruit and eat the rest.

2. When is the best time to prune lilacs? This caller has one that is a large, overgrown lilac that needs to be pruned.

A. The best time to prune a lilac is in the spring within a couple of weeks after blooming has concluded for the season. If it is a very large, old plant, it can be pruned all the way back to 6-8 inches above ground in a rejuvenation pruning. Rejuvenation pruning does just what the name says, rejuvenates an old, less productive plant to provide better foliage, flowering, and overall health. Rejuvenation pruning can be done in the fall. The lilac will not flower for a couple of years following this type of pruning, but it will bloom again.

3. This caller planted a large amount of black walnuts last year. Now the weeds are taking over the trees. How can the weeds be controlled without injuring the trees?

A. Simazine is a pre-emergent herbicide that can be used around walnut trees that have been established for at least 12 months. This is a pre-emergent herbicide so it won’t clean up the weeds that are growing now. For those weeds, it would be best to do hand weeding with a hoe to not injure the roots of the trees and then apply the Simazine this fall. Be sure to follow the label on how to apply and how to mix the chemical.

4. A caller has a redbud tree that is 15 feet tall and is now developing a split where multiple leaders have forked up from the main trunk. What can be done to prevent further splitting? Can one side of the tree be removed to fix the split?

A. The best option would be to remove one side of the tree or bolt it together. However, removal of one side of the split would result in removing too much of the canopy of the tree. Either side of the split would be pruning off a branch that is more than 1/2 the size of the trunk, which is not recommended. Because this is a redbud, and it shouldn’t get much larger than it is now, bolting the 2 sides together may be an effective management option for this tree. A bolt in a larger tree in this situation would likely not be very effective once the tree grew to full size, but with a smaller tree it would be more beneficial. The best thing for all trees is to remember to prune them while they are young to prevent these situations from occurring, but that is not always an option and it is hard to remember to do this.

5. This caller has some pin oaks that were planted 2 years ago and are 2-4 feet tall. The new leaves are being eaten off the tree. The leaf veins are still on the tree, but most of the rest of the leaf is gone. He has looked and can’t seem to find any caterpillars. What would cause this and how can it be managed?

A. This is likely due to scarlet oak sawfly. It is a common pest of oak trees that has 2 generations per season here and we are just finishing up the second generation in the immature stage. Because the damage is mostly finished for the year and because the tree faced minimal damage, there is no need to spray for this sawfly.

6. A caller had a daylily plant that she transplanted a month ago and it died. What caused that? What time of year is best to transplant peonies?

A. June and July are not the time of year to transplant anything, it is too hot, humid and dry to move a plant. I would assume the daylily died due to heat stress. When a plant is moved, it takes time to build the roots back up to where they can survive such heat and low water that we see in the summer months. It is best to wait to tranplant anything until the spring or fall of the year so they can become established in cooler temperatures than in the heat. Peonies can be transplanted this fall, in September. Remember to keep the plant at the same depth in the soil or it will not bloom.

7. The last caller of the day sent some photos of his red maple trees wanting to know if they will survive?

A. The trees were planted last year and now one of them has no leaves on the top 1/2 of the canopy of the tree. The other has very wilted leaves. When the top half of a tree dies like this, it is likely due to a watering or root issue. I would say this tree should be replaced, it will not grow out of it. The roots could have been injured in the nursery or at the garden center he purchased the trees at. The roots also could have been injured when they were planted. The tree that is still fully leafed out may have a chance to live, give it TLC and it might pull through. Water the tree with 1 inch of water per week and add a mulch ring around the tree that is 2-3 inches deep. The leaves could be wilted due to heat and drought stress and the watering and mulch will help it to survive.

Yard and Garden: July 20, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for July 20, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 3, 2018. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: John Porter, Urban Agriculture Program Coordinator for UNL Extension and Nebraska College of Technical Agriculture (NCTA)

1. The first caller of the day has holes in her yard that are 1-1.5 inches across. Is this ground squirrels? How can she control them?

A. This does sound like damage from ground squirrels. Ground squirrels can be controlled through trapping, baits, or toxicants. For more information on controlling ground squirrels, visit this guide from UNL Wildlife.

2. This caller has Virginia creeper that is having some issues. The first set of leaves have rust spots and holes on them and the new leaves are showing up but the buds are not opening. This plant is growing in part sun. What is wrong with it?

A. This could be a fungus on the leaves of the Virginia creeper that is leaving a shot-hole appearance behind when the dead areas of the fungus get dry and brittle and fall out of the leaf. If it is a fungus a copper fungicide or chlorothalonil to control it. There could also be some heat stress occurring causing the new leaves to not open up. There is also a possibility that herbicide drift has also occurred that has caused the leaves to not open up.

Harlequin Bug, Alton N Sparks, Jr, Univ of GA, Bugwood

Harlequin Bug photo from Alton N. Sparks, Jr., University of Georgia, Bugwood.org

3. A caller has horseradish with bugs on it that are beetle-like and are black with orange spots on them. What are these bugs and how can they be controlled?

A. These are most likely Harlequin bugs. They can be found on horseradish and they can do a great deal of damage. Harlequin bugs are a true bug, like a stink bug, They suck the juices out of the leaves of our plants leaving them wilted and discolored. They can be managed with the pesticide sevin.

4. A walk-in listener works with the football field in town. They have brown spots throughout the field and have found some caterpillars and a large amount of tiny, worm-like creatures. What are these? What is causing the brown spots? How can these problems be solved?

A. These caterpillars are sod webworm. They are a pest of turf. These caterpillars can cause brown spots in the lawn. Triazicide is labeled for sod webworms and would give pretty quick knockdown. The worm-like creatures found on the lawn could be nematodes or they could be fungus gnat larvae. Fungus gnat larvae rarely cause serious damage outside.

5. This caller is having difficulty with tomatoes ripening. What is the problem?

A. The hot weather is causing poor pollination. The pigments responsible for the red color in our tomatoes are not produced when the temperatures exceed 85 degrees. So, when we see long stretches of very hot weather, our tomatoes will not ripen. Be patient, they will ripen eventually when the very hot temperatures recede.

6. A caller is having problems with weeds in his asparagus. Will preen work now to control the weeds? Also, does he need to water his asparagus in the winter months because his asparagus isn’t growing very well.

A. Preen should be applied in the spring to control annual weeds, it will not do anything to control weeds that are already growing in your asparagus. At this point, hand pulling and applying a layer of mulch would be the best option for managing the weeds in the asparagus. When the asparagus is cut back this fall or before it begins to grow in the spring, glyphosate (Roundup) can be used to control the weeds. The glyphosate product can be used directly over the asparagus patch as long as no green from the asparagus is growing above the ground. Then, apply a layer of preen (make sure it is labeled for use in the asparagus) and add the layer of mulch.

Bagworm4

Bagworm

7. The last caller of the day has bagworms in their windbreak. The bags are 1-1.5 inches in length. What should they do about these?

A. Pesticide sprays for bagworms are not going to be as effective now. It is better to control the bagworms from when they hatch until they are up to 1 inch in length. Spraying a chemical now would kill some, but the rate would not be nearly as effective as before. It might be better to just handpick the ones you can reach and watch for it next year to be able to spray sooner in the season when it is more effective.

Problems in our Gardens

Vegetable garden 1

Growing my own produce in my backyard is one of my favorite things of summer! Vegetable gardens are great exercise, give you an excuse to eat healthier, and are very enjoyable but they can be a lot of work as well. There are always problems in our vegetable gardens, usually they are temporary or easily fixed.

Production Issues

The weather this year has not been favorable to our plants. We have been facing aborting flowers of our plants due to heat and low pollination. Now, even though our plants are producing, the tomatoes are not ripening up. The hot weather contributes to this as well. When temperatures are consistently as hot as they have been lately, tomatoes may develop but they don’t turn red. According to Purdue University, the pigments responsible for the red color in our tomatoes are not produced when the temperatures exceed 85 degrees. So, when we see long stretches of very hot weather, our tomatoes will not ripen. Be patient, they will ripen eventually when the very hot temperatures recede.

Blossom end rot is also starting to show up in our gardens. Blossom end rot is when the blossom end (the end not attached to the plant) begins to rot. This is due to uneven watering, which is seen quite often in the early part of the growing season where we see stretches of drought surrounded by 2-3 inch rains. Again, this should fade through the season as the plants grow through it. You can still eat the other end of the tomato and discard the rotted end or give your plants time, the next harvest should be better.

Cracks may also start to appear in our tomatoes due to the weather. With uneven watering comes cracks in our developing fruits. Our fruits can grow rapidly due to rapid intake of water which can build up pressure in developing tomatoes. Cracks typically appear on the top of the tomato, often in rings, and are not harmful to us if we eat them. Check for insects that may have gotten into the cracks of our fruits before eating.

2018-07-18-20-05-36.jpg

Grass clippings are applied as mulch around zucchini and cucumbers

Using Mulch

Mulch is a great way to combat these issues. Many of our problems in our gardens stem from uneven watering or plants that got too hot and dry to deal with the stresses of the environment. Mulch can keep moisture around the plants and keep the roots cooler to help with these issues as well as reduce competition from weeds. Grass clippings make a great mulch. If the grass has been treated with any herbicides this season, look at the label to know if or when it can be used as a mulch. Grass clippings break down quickly so they should be reapplied often. Straw is also a great mulch for the garden and it wouldn’t need to be reapplied as often. These types of mulch can then be tilled into your garden at the end of the season or before next season to add nutrients back into your soil.

squash vine borer damagePests

Squash bugs and squash vine borer are seen in our gardens every year. Squash bugs cause yellow speckling on the leaves and feeding damage on the fruits. You may also see rusty colored eggs on the underside of the leaves that can be removed and destroyed. Squash Vine Borer causes rapid death and wilting of the plants. These pests feed on plants in the cucurbit family, which includes zucchini, squash, cantaloupe, watermelon, cucumbers, pumpkins, gourds, etc. Squash vine borer can be controlled by wrapping the stem of your plants with aluminum foil to stop the females from laying their eggs on your plants. Other controls include Carbaryl (Sevin), Permethrin (Eight), or bifenthrin (Bifen). This will need to be reapplied often through the growing season. It is best to switch between at least two of these products to avoid resistance from developing.  Always follow the label recommended rates and follow the pre-harvest interval listed on the label when harvesting fruits and vegetables after using chemicals.  Spray the undersides of the leaves and the base of the plant thoroughly.  All sprays should be done later in the evening to avoid damage to bees and other pollinators.