Late Fall Lawncare

The fall is a great time to improve our lawns. We have now passed the correct timing for overseeding lawns, but there are other improvements we can still make. Controlling perennial broadleaf weeds and winter annual weeds can be done in October and fertilizers may be applied if necessary.

Broadleaf weeds

perennial lawn weed collage
Perennial Broadleaf Weeds

Perennial broadleaf weeds including dandelions, creeping Charlie or ground ivy, and clover are best controlled in the fall once the weeds have begun their preparations for winter. In the fall, these perennial weeds will move sugars that they use for energy from the above ground portions of the plant down into the roots to store them for next spring. If they are sprayed during this phase of their lifecycle, they are more likely to take that herbicide down into the roots to be more effective than if done in the spring. Spray these weeds with a 2,4-D product 2 or 3 times from late September through the end of October. Wait to spray after temperatures consistently drop to below 80 degrees so the herbicide doesn’t volatilize in hot, humid weather.

Weedy grasses

2018-04-20 12.52.00
Henbit in bloom in the spring

The fall is not the time to worry about or treat for summer annual weeds such as crabgrass. Those plants that are still alive will die with the first frost and the seed will not germinate until next spring when the weather warms back up again. However, you can treat now for winter annual weeds such as henbit and speedwell. Once they have germinated this fall you can use a 2,4-D product, which can be applied as a late October application both for the winter annual weeds and for perennial broadleaf weeds.

Using pesticides correctly

Remember, when using pesticides always be careful and apply pesticides according to the label. Any material used to maintain a landscape, including fertilizer, sand, or pesticides, can end up in the storm sewer and lead to pollution of lakes, rivers, and streams. In the same manner, even our grass clippings and leaves can pollute our water supply. There are ways to manage our landscapes while reducing water pollution.

The following will help when managing our lawns this fall:

  1. Any fertilizers, pesticides, and grass clippings should be swept back onto the landscape. Using a leaf blower will work as well. The idea is to keep these items on plant material rather than on the hardscape that leads easily to the storm sewer.
  2. Raking up leaves in the fall will also help reduce the amount of leaf debris that ends up in water.
  3. Check your sprayers before using to ensure they are properly calibrated and the nozzles are not clogged.
  4. Thatch layers in the lawn can become a natural barrier to prevent infiltration. Aerate the lawn to reduce the thatch layer to allow lawn products to infiltrate their intended areas.

Fertilizer

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 in mid-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.

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Apples

Fall is a great time of the year. It can be bittersweet, though, because it often signals the end of our growing season. The good thing is that this is also the time of the year to go pick apples.

Harvest

Each different variety of apple differs for their harvest time. To determine the harvest time for the apple, knowing the variety will help you. In fall, a common question from gardeners with a favorite apple or pear tree is for identification of the cultivar from the color and shape of the fruit. This almost impossible to do, in fact, it’s really only realistic to give a general idea of possible cultivars. So, if you don’t know the variety, you can look at the color, flavor, and texture of the apple.

To know a mature apple, look at the “ground color”, which is the color of an apple’s skin disregarding any areas of red. For red-fruited cultivars, observe the portion of the apple that faces the interior of the tree. When the ground color turns from leaf green to yellowish green or creamy yellow, the apples are ready to harvest. In yellow cultivars the ground color will become a golden color when they are ready to harvest. You can also taste one to ensure that it is the correct sweetness and make sure it is firm and not overripe and soft. Overripe apples will detach from the tree more easily than those that are at the correct stage of ripeness. If the apple is too ripe, it will break down in storage more quickly than those that are at the peak of their maturity.

Storage

For storage it is best to pick apples when they are still hard but mature. Place the apples in a box or crate with a smooth lining so that staples don’t puncture or injure the apple. They can be stored in boxes or crates lined with plastic or foil to retain humidity around the apples. They should be stored in the fridge or other location where they are kept at temperatures around 32 degrees Fahrenheit, an apple stored too warm will ripen faster.

Remove bruised and large apples that will break down more quickly than the rest of the apples. Apples produce ethylene gas, even after they are removed from the tree, which speeds up the ripening process in fruits, including apples that are stored together. A damaged apple will produce more ethylene than other apples. Damaged and large apples should be eaten or processed first and not stored like the other apples.

Tree Selection

Fall is also a great time to plant a tree. If you are reading this article thinking you should plant an apple tree so you can start to have your own apples to harvest, there are some great choices. One thing to remember when choosing an apple tree for your landscape is to get a variety that is resistant to cedar-apple rust and apple scab. These 2 diseases are very problematic for apple trees in Nebraska and require spraying multiple times throughout the growing season to combat. There are also some varieties that are resistant to fire blight which can also be very damaging to your apple crop and would be a good trait to look for in your future apple trees.

Some good apple tree choices include Liberty, Enterprise, and Freedom which all have good disease resistance for the most common diseases. Enterprise is self-unfruitful and therefore does require a pollinator tree be planted nearby when planting Enterprise. Honeycrisp is a delicious apple that many people want to plant. However, it is susceptible to cedar-apple rust and powdery mildew so you would need to spray for those diseases. It is moderately resistant to apple scab and resistant to fire blight. Honeycrisp is also only moderately strong for tree growth, so it could break more in storms.

*The information on Harvest and Storage came from Sarah Browning, Nebraska Extension Educator in Lancaster County.

Wild Cucumber

Windbreaks are very important to many acreage owners throughout Nebraska. A windbreak is used to block the wind, as the name implies. Winter winds can be very strong and a windbreak will help to reduce those winds, which will in turn reduce heating bills. Windbreaks can be built from a variety of trees and shrubs which are typically fairly tolerant of many problems. However, we do still see problems from bagworms, some fungal diseases, and weeds growing around the trees. A windbreak weed that is quite prevalent this year is wild cucumber or burcucumber.

About Wild Cucumber

Wild cucumber is an annual weed that grows up and over our windbreak trees. Due to all the rain we saw this spring, it is growing voraciously over our trees across the Nebraska countryside. It vines and has leaves similar to cucumber plants. The leaves are arranged alternately along the stem and have five triangular-shaped lobes on the leaves. The leaves are large, 4-10 cm long and 4-13 cm wide. If left on the trees long enough, a fruit will develop. The fruits of wild cucumber resemble a shorter, stouter cucumber with spines all around the outside. The plant climbs up onto our desired trees through the use of tendrils that twist around small branches to hold the plant up as it grows.

There is also a burcucumber plant which is closely related to wild cucumber. Burcucumber is also an annual weed that vines up and over windbreak trees. The leaves of burcucumber are more rounded and the lobes are not as deep as the lobes on the leaves of wild cucumber. Also, the fruits of burcucumber are much smaller and held in a groups. Wild cucumber and burcucumber are similar enough that management for both plants is the same and the names are often used interchangeably.

Managing Wild Cucumber

Wild cucumber is a plant with a shallow root system, so it pulls very easily. At this time of the year, this is really the only way to manage wild cucumber. Don’t spray 2,4-D or any other herbicide on the vines because anything that would control the wild cucumber can damage or even kill the trees that wild cucumber is vining up on. It would be best to pull it off and kill the plant before any fruits are produced to reduce the seedbed. However, at this time of the year they have already begun to produce fruits.

Since wild cucumber is an annual plant, it can be controlled with a pre-emergence herbicide in the spring. Products containing simazine will work to control this weed before it emerges next spring. Early May would be a great time to apply the chemical around the trees in your windbreak to make sure it is in the soil before the wild cucumber germinates. If you are having troubles with this weed this year due to the excess moisture, it would be beneficial to use the simazine next spring or you could have a similar or worse problem next year.

Weather & Plants

 

The environment impacts our plants in many ways. We are always happy to see the shift in weather to help the heating and air conditioning costs of our homes. Plants are also very happy when the weather changes to a more comfortable temperature. Extremes for moisture and temperature can be very damaging to our plants on both ends of the spectrum. This year we have seen a wide range of these problems which are negatively impacting our plants. To say we have a “normal” growing environment or weather pattern in Nebraska is almost unheard of and this year was unlike any we have seen recently.

Floods

2015-06-04 18.32.28Typically we are excited to see rain throughout the season. However, when the rain doesn’t seem to end, like this spring and even again now, this can harm our plants. There is such a thing as overwatering plants. Plant roots need to breathe too, if they don’t have the oxygen they need they can start to develop root or crown rot that can kill the plant.

Besides problems with root growth and development, many fungal diseases have been popping up on our trees this summer. There are many leaf spots on our trees such as maples, oaks, pears, and crabapples as well as on our vegetable crops such as tomatoes, cucumbers, and others. The cool, rainy environment this spring led to the infection which is showing up now. Spraying so late in the season won’t really help. The best thing for these plants is to just keep them healthy through the season and then use sanitation in the fall to reduce the diseases next year. Destroy fallen leaves at the end of the season by raking them up and throwing them into the garbage and remove annual plants from the garden. Don’t compost infected plant parts because the spores may not be killed in a compost pile. Leaves left at the base of the plant or vegetable plants left in the garden will make a good location for the disease spores to overwinter and move back into the plant next spring.

Heat

Hot temperatures can be problematic for our plants, especially when that heat comes on fast after such a long, cool spring and winter. We have had problems with leaf scorch showing up on plants when we had that swing of temperatures into the 100’s with high humidity. This extreme heat is damaging to our plants, but especially this year when they were accustomed to cooler temperatures with more than enough water available to them. Scorch is still apparent on trees even though temperatures have cooled back off. For the survival and health of our plants through extreme heat, keep a 2-3 inch layer of mulch around the plants and keep them well watered when rains end in the summer.

Excessive cold

Excessive cold temperatures that we saw this winter can also harm our plants. The good thing for Southeast Nebraska was that we had snow cover most of the winter this year. If we had seen that much wind and cold temperatures without snow insulating the roots and crowns of our plants, we would have seen a lot more dieback.

Some of our plants did still have problems from the cold and some had problems from the high salt buildup around our plants from all the snow. Evergreen plants still transpire through the winter months. Desiccation happens when the moisture released from plants through transpiration exceeds moisture taken in through the roots. White pines see desiccation quite often in the winter months on the north side from the strong winter winds we see in Nebraska. This desiccation becomes even worse on plants that are in an area where snow with deicing salts are piled up each time we scoop snow.

There isn’t much to be done to fix trees now that desiccation has set in. For this coming winter, it would help to water the trees once a month on a warm day in the winter. You can also apply anti-desiccant products once every six weeks beginning after plants have completely hardened off, usually in late November. Continue applications through mid to late February. Avoid covering plants so heavily they become sticky with needles glued together. Have warm, soapy water nearby and clean out the sprayer immediately or equipment may be ruined by the product.

Yard and Garden: August 2, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for August 2, 2019. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am. 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.

Guest Host: Dennis Ferraro, Extension Wildlife Specialist, UNL

1. The first question of the show was about pole green beans. They were planted in May and have been blooming but have not produced any beans yet. What is wrong with them?

A. This is likely due to the abnormal weather pattern we have seen this spring and summer. Make sure that the plants are mulched and watered evenly, as much as you can. Also, the warmer night temperatures will keep the beans from developing.

2. A caller has lilacs that are 2 feet tall. They have rust spots on the leaves. What is causing this?

A. This is likely due to a fungal disease. Make sure you are watering from the base of the plant and keep mulch around the plants. Fungicides can be used but if it is just on a few leaves, just pull those off and destroy them. It also is a little late to spray fungicides on the plants this year. At the end of the year clean up all the fallen leaves from around the plant to prevent re-infection next year.

3. This caller has turf that continually gets brown patch every year, it is only getting one hour of sunlight per day. What can be done to help reduce this problem?

A. Unfortunately, the turf isn’t growing well in this location. Turf is a full sun plant and needs at least 6-8 hours of full sun per day, not dappled light. In this location the turf will always have problems. It might be a good time to switch to another plant underneath the trees. Shade perennials or groundcovers could replace the turf and they would grow much better there. Sedges are another good choice that look very similar to the lawn but would tolerate the shade better.

4. What can be used for weeds in a driveway?

A. Roundup 365 would be a good option for this. It contains glyphosate as well as imazapic which lasts longer than the glyphosate alone. On the label it states to only apply once a year and to “spray until THOROUGHLY WET”, so for best results spray to this extent. Soil sterilants aren’t recommended because they often run off into adjacent plant material such as grass and kills it. You could also use pre-emergent herbicides in the spring to help with annual weeds. Always read and follow the label when using pesticides.

5. A caller has bagworms in his windbreak. What can be done for bagworms now?

A. It may be a little late in the year to treat chemically for bagworms. Once they get much larger than 1/2″ in length, their feeding is reduced and sprays are not as effective. Also, the majority of their damage is done for the year. If you decide not to spray, it would help to go out and pick as many of the bags off as you can and destroy them.

Sandbur, Rebekah D. Wallace, Univ of GA, Bugwood
Sandbur, Photo courtesy of Rebekah D. Wallace, University of Georgia, Bugwood.org

6. How do you control sandburs?

A. Sandburs are an annual grass, so using crabgrass pre-emergent herbicides in the spring will also kill germinating sandbur seeds. Also, sandburs are easily out-competed, so if you can get something else to grow in the area, the sandbur population will be reduced.

7. This caller has Japanese beetles on Linden trees. What can be done to control them? Will the trees die from this?

A. The trees should be fine next year and will leaf out fine. You can spray the trees now with Sevin or chlorothalonil. Next year, you can spray with these products after the bloom period or when the beetles first appear. Do NOT use a systemic insecticide on linden trees due to the high amount of pollinators that are found on lindens.

8. A caller has a problem with squirrels eating his sweet corn. What can be done to stop the squirrels?

A. For a small plot of corn, you can drape bird netting over the corn and use fishing weights to hold it down. From Control of Tree Squirrel Damage NebGuide “Wire mesh fences (no larger than ½-inch weave) topped with electrified wire or mesh enclosures may be practical for keeping squirrels out of small areas. Electrified wires are not recommended for use where there are children or pets. Little else can be done with squirrels in larger areas, other than re-moving the offending squirrels by cage trapping or shooting where safe and legal.”

9. This caller has an apple tree that is covered with Japanese Beetles. She sprayed Tempo on the tree, can she still use the apples?

A. No, fruit trees are not listed on the label. When using pesticides be sure that the plant you are spraying the pesticide on is on the label. With fruits and vegetables, watch the PHI (pre-harvest interval) to know how long to wait between application and harvest.

10. A caller has pin oaks and something seems to be eating the leaves. The leaves are dying and this is a young tree and he is trying to avoid using pesticides. What can be done?

A. This damage could be from grasshoppers or beetles, most of the damage seems to be happening at night so it could be chaffers that are active at night. Using a neem oil or insecticidal soap would work for these pests as an organic option.

11. This caller is having troubles with a groundhog. How can manage the groundhog?

A. Trapping works best for groundhogs. Put burlap over the cage because groundhogs are spooked easily. Use a half an apple or half an ear of corn for bait. Wire the cage open for a few days to allow the groundhog to take the bait and become more relaxed with the trap. Then, after a few days set the trap without wiring it open. Once you catch the groundhog, you cannot translocate it. It must be euthanized with a firearm if legal where you are or take it to animal control. Be sure to check local laws before controlling this groundhog. For more information, visit wildlife.unl.edu

12. A caller is trying to control his bagworms, what chemical can he use for bagworm control?

A. Tempo is a great choice, but sevin or any other general insecticide will work. It may be a little late in the year to treat chemically for bagworms. Once they get much larger than 1/2″ in length, their feeding is reduced and sprays are not as effective. Also, the majority of their damage is done for the year. If you are planning on still spraying, get it done very soon.

13. The last caller of the year called to say “Thank You!” He removed brome grass competition from around his trees, thanks to advice from the show, and now his trees are growing much better.

*Disclaimer ­- Reference to any specific brand named product does not constitute endorsement, recommendation, favoring or implied criticism if similar products are not mentioned by Nebraska Extension in Gage County.  Identifying specific pesticides are for the convenience of the reader and are generally most commonly available.  Always read and follow the pesticide label.

Yard and Garden: July 26, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for July 26, 2019. 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 2, 2019. 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: Bob Henrickson, Horticulture Program Coordinator for the Nebraska Statewide Arboretum

1. The first question of the show was about catalpa trees. They were pruned in the past, but now they have a bunch of smaller branches growing out of the location where the branch was removed from the tree.

A. The branch that was removed was likely not correctly done. If the cut wounded into the trunk of the tree or left a stump, it would cause the tree to push a lot of new growth like suckering. Make sure that proper pruning cuts are followed and that you don’t leave a stump. Follow these steps when pruning a tree to ensure it is removed correctly with minimal damage and avoid the branch-bark collar to avoid a flush cut which will not heal correctly.

3-step pruning cut
Proper pruning cut, University of Missouri Extension

2. How do you control clover in the lawn?

A. Clover can be found in an under-fertilized lawn. It may be a good practice to fertilize at least one time a year to help the lawn compete with the clover. If treating with chemicals, the fall is the best time of year to treat for broadleaf perennials such as clover, dandelions, and creeping Charlie. Apply a 2,4-D product or one containing triclopyr twice in the fall. Mid-September and again in mid-October is best. Other IPM strategies for controlling clover include mowing high and aeration if necessary.

Co Potato Beetle Pupa 2
Colorado Potato Beetle Pupa

3. A question came in via email about orange things on potatoes. There are tiny orange bugs found on potato plants in her garden. What are they and how can they be controlled?

A. These are Colorado potato beetle larvae. Pull any off that are found and smash them or spray with sevin to control them as they emerge as beetles.

4. A caller has creeping Charlie in their yard. When is the best time to spray for that?

A. When using chemicals, the fall is the best time of year to treat for broadleaf perennials such as clover, dandelions, and creeping Charlie. Apply a 2,4-D product or a product containing triclopyr twice in the fall. Mid-September and again in mid-October is best. Other IPM strategies for controlling creeping Charlie include mowing high and aeration if necessary.

5. This caller has cucumber plants with a lot of flowers but no fruits. Why are these plants not producing fruits?

A. You should check the flowers to see if they are all male flowers or if there are female flowers as well. Male flowers just have a skinny stalk behind the flower. Female flowers have a tiny cucumber behind the flower. If male flowers are all that are present, give it time for the plant to produce female flowers. If both male and female flowers are present, there could be a problem with pollinators. Avoid spraying while bees are active, attract bees with other pollinator plants, put up a bee house to bring bees in. If you are using row covers, be sure to uncover the plants for a while during the day so bees can pollinate the plants.

6. A caller called in with a good suggestion to help with cucumber plants. He grows his on a trellis so they can get better airflow and less diseases. It also makes it easier to harvest the plants this way.

7. This caller has a small hackberry that is 12-14 feet tall with 3 trunks growing together. There are small splits all along the trunk like some type of injury, what caused this and will his tree be ok?

A. These could be spots from hail injury, even from a few years ago. There is nothing to do for hail damage. Most trees will come through just fine. If the damage is intense, the tree could have more problems.

8. Is it too late to trim lilac bushes?

A. Yes, it is too late for general pruning of lilacs. They should be pruned within the first couple of weeks following the flowering period. If a rejuvenation pruning is desired, the fall would be a good time to do that, wait until late September to mid-October for that.

9. A caller who manages a golf course has a couple of Linden trees that were under water for about 2 months this year. They sat in a flooded area of the golf course for this time in the spring. They originally did leaf out but since then the leaves have turned brown. Will the tree be ok?

A. There is likely no life left in these trees. Lindens are not adapted to have their roots that wet for that long. The trees probably had enough energy left in the roots to push out leaves but now have ran out of energy. It would be best to remove those trees and replace them with something more adapted to sitting in water from time-to-time, such as bald cypress trees.

10. The final question of the day was sent via email. This listener has a gravel driveway that is partially sloped. How can they keep the weeds out of this driveway and not harm the grass at the end of the slope?

A. Roundup 365 would be the best option for this. It contains glyphosate as well as imazapic which lasts longer than the glyphosate alone. On the label it states to only apply once a year and to “spray until THOROUGHLY WET”, so for best results spray to this extent. Soil sterilants aren’t recommended because they often run off into adjacent plant material such as grass and kills it. Always read and follow the label when using pesticides.

*Disclaimer ­- Reference to any specific brand named product does not constitute endorsement, recommendation, favoring or implied criticism if similar products are not mentioned by Nebraska Extension in Gage County.  Identifying specific pesticides are for the convenience of the reader and are generally most commonly available.  Always read and follow the pesticide label.

 

Yard and Garden: July 19, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for July 19, 2019. 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 2, 2019. 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: Jay Seaton, District Forester for the Lower Platte South NRD

blossom end rot zucchini
Blossom end rot on a developing zucchini

1. The first question of the show was regarding fruit development on zucchini. The fruits begin to develop and then one end begins to die. What is causing this?

A. This sounds like blossom end rot, it can happen in zucchini, tomatoes, peppers, watermelons, and others. Blossom end rot is when the end of your vegetable that is away from the plant rots and turns black. It occurs on the end of the vegetable that had the flower, hence the name blossom end rot. The cause of this disease is a calcium deficiency, but calcium is in the soil in sufficient quantity, uneven watering will reduce the ability of the plant to access this calcium. Calcium has to be dissolved in water for the plant to be able to obtain it from the soil. Adding calcium to your garden is not effective for managing this problem. Not all of your produce should be affected by this problem, they tend to grow out of these conditions later in the summer, so there is no need to treat your garden for blossom end rot. Maintain moisture and mulch to help with this disorder.

This caller also wondered why his pole beans are not producing yet. He shared the seed with a friend and that friend has harvested but he has not. Why is that?

A. This is likely an environmental issue. Give the plant a little more time to produce the beans. The friend’s garden would have a different microclimate from your garden it may have more sunlight or more heat radiating from a nearby building that your garden doesn’t have.

2. This caller has zucchini that is dying. They seem to have rotten roots when going to look at why they have died. She waters with a hose on trickle twice a week for 30 minutes each time. What is wrong with them?

A. This sounds like too much water is getting applied to the plants. Jay estimated that this was likely applying about 5 gallons of water per week, which is quite excessive. It would be better to use a soaker hose or measure the amount of water applied to the plants each time you let the hose trickle. Vegetable gardens only need about 1 inch of water per week.

3. A caller has pickling cucumbers that are growing good but as they grow one end of the cucumber becomes smaller than the other end. What would cause this?

A. This is likely due to heat stress. There isn’t much we can do to avoid damage from the hot weather. Make sure that the plants are mulched and they are receiving the correct amount of water.

4. This caller has tomato plants with brown leaves at the bottom of the plant. What is causing this?

A. This is likely a fungus. We have seen quite a bit of early blight this year already. Look for concentric rings in the brown spots on the leaves. If it is just a few leaves, pull those leaves off the plant and destroy them. Be sure to keep the plants mulched and water from the base of the plant rather than overhead irrigation to help reduce the spread of the disease.

japanese beetle JAK582
Japanese Beetle, Image from Jim Kalisch, Retired from UNL Entomology

5. What can be done about Japanese beetles? This caller said she was going to try traps and wondered about homemade traps.

A. Don’t use traps, they will attract more Japanese beetles than what you have in your landscape already. Spray all of the areas at the same time. She said one day she would spray the garden, the next a shrub, and the next a tree. If you avoid spraying in areas where they are commonly found, those other locations will become a safe haven for the beetles. Sevin is a good insecticide to use to control the beetles. Be sure to read and follow the label for spraying every 10-14 days and for the PHI, to know when it is safe to harvest again after spraying. Using grub control in the lawn can help. You can also go out in the evening when the beetles are grouped up to knock them into a bucket of soapy water to kill them.

6. This caller wants to know if they should hold back on fertilization of roses and garden now due to the heat?

A. If your plants look fine, don’t worry about fertilizing them right now. Avoid fertilizing the vegetable garden this time of the year. If the nitrogen level is too high around vegetable plants, the plants will grow large and beautiful but will not produce fruit because nitrogen is for leafy growth of the plant. I usually advise avoiding fertilization of the garden this late in the season.

7. The last caller of the day has a sweet potato vine with holes in the leaves. She saw a grasshopper the other day, would that be causing the problem?

A. This could be from grasshoppers, especially since you saw some on the plant. Use Sevin to treat for them. Make sure you spray the grassy ditches and roadsides as well, which is where grasshoppers are found more often.

She also has zucchini plants that have gray, translucent spots on the leaves. What would cause that?

A. She sent a picture to clarify the problem. It looked like a slight fungal disease. It is nothing that is too damaging to the plants. Copper fungicide could be used but I don’t think it is necessary. Good sanitation is key to controlling fungal diseases in the garden. Mulch the garden and avoid overhead irrigation during the season to help prevent splashing spores from the ground and from plant to plant. Remove the plants from the garden at the end of the season.