‘Right Plant, Right Place’ is a very important aspect of planting and it is a great time to start thinking about it while building on what I wrote in my last article. The seed catalogs… More
It’s cold outside these days and our trees are still alive, they are just dormant. And even a dormant tree, still needs care during the winter months.
We have always pruned deciduous trees in late winter, however new research shows the optimum time to prune is really in the late spring to early summer. It was determined that it is best to prune trees when they are most actively growing to promote quick wound sealing.
You may not always have a choice on pruning time based on the company you hire or if pruning is to repair damage from a storm. Also, some trees such as maples, willows, birches and others will produce a lot of sap if pruned in the late winter or early spring, they should be pruned in late fall. Oaks should not be pruned from April-July to avoid damage from oak wilt disease, they can be pruned in the late fall as well.
Ensure adequate watering throughout the entire growing season for all trees and shrubs, especially those recently planted. Water throughout the winter when the ground is not frozen, as necessary. Winter watering should occur around midday on days when the temperature is at least 40-45 degrees Fahrenheit 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, watering is not necessary. However, if pushing the screwdriver into the soil is very difficult, plants should be watered.
Winter desiccation commonly occurs on evergreen types of trees and shrubs and is more common in winters with little or no snow cover when plants are exposed to cold, drying winds. All trees transpire, or lose water, even through the winter. Evergreens transpire at a higher rate than deciduous trees and therefore suffer more during winter. Winter desiccation occurs when the amount of water lost is greater than the amount of water the plant takes in throughout the winter. The damage appears as brown needles on branch tips. However, the damage does not usually show up in our trees until early spring, so they will stay green through the winter. Winter desiccation can be managed through winter watering and anti-desiccant sprays.
Anti-desiccant sprays, or anti-transpirants, help reduce transpiration water loss from foliage. Most are an emulsion of wax, latex, or plastic to put a thin film on the foliage and reduce water loss. Plants such as arborvitae, pines, boxwoods, and others can benefit from using an anti-desiccant spray to protect them through the winter. Anti-desiccants should be applied after late November, once they have completely hardened off. Do not apply these products too early in the year. They can be reapplied through the winter or until mid to late February. Always read and follow the label for how to apply and how often to reapply.
The trunks of young, tender barked trees are prone to winter sunscald until the tree is mature enough that the bark becomes thick and woody. Damage occurs to the south or southwest side of trees during warm winter days. Sun shining on the bark heats it up. Damage occurs when bark cells lose some of their cold-hardiness during the day, then are damaged as temperatures fall below freezing at night. Damage can be seen as discolored and/or sunken bark, peeling bark or bark cracks in the years following the incident. Once the damage has occurred there is no cure for it. It is better to wrap the tree with a tree wrap through the winter months to protect it before the damage occurs. Remove the wrap in the spring to avoid other insect and disease problems from occurring under the wrap.
It’s hard to believe, but it is nearly Thanksgiving again, let the holiday decorating begin. I know a lot of people go out on Thanksgiving weekend to pick out their Christmas tree for the holiday season. So, I thought it was a good time to discuss this holiday decoration.
There have been many different civilizations throughout history that have used evergreens in their homes, decorated or not, to celebrate the holidays, according to the University of Illinois Extension. Christmas Trees came to the United States in 1747, when people in Pennsylvania decorated wooded pyramids with evergreen branches and candles. By 1850, decorated Christmas trees were a widely used tradition in America. The first retail tree market was in New York in 1851 and the first U.S. President to put a Christmas tree in the White House was Franklin Pierce in 1856. The first national Christmas tree was put up in 1923 on the lawn of the White House by President Calvin Coolidge.
There are many tree species to choose from for your Christmas tree. The most common tree species used for Christmas trees include: Balsam Fir, Douglas Fir, Fraser Fir, Noble Fir, Scotch Pine, Virginia Pine and White Pine. If you have a lot of heavy ornaments, look for a Fraser Fir, Scotch pine, blue spruce or Black Hills spruce because they have stiff branches that will hold ornaments better. Balsam Fir is the choice for those looking for a Christmas tree scent. White pines can be used for areas where you prefer softer needles.
Before leaving to go pick out your tree, measure the area of the room where the tree will be placed to ensure you get a tree that fits the space. You don’t want to have broken windows like Clark Griswold in the National Lampoon’s Christmas Vacation movie.
When choosing your tree, assess the tree condition. Walk around the tree to look for holes in the branching. Slightly tug on the needles that are on the tree to ensure they are tightly attached to the tree and have some flexibility. Also, give the tree a good shake, if green needles fall off or if it has a lighter green color that is not a fresh tree, choose another. Brown needles will naturally fall from the interior of the tree, that doesn’t mean there is a problem with it.
When you take your tree home, place it immediately into the tree stand with plenty of water. If the tree was cut within the past 12 hours it doesn’t need to be recut but if it has to sit longer than 12 hours prior to placing it in the stand, it will need to be recut to improve water uptake. Place the tree in a stand that holds at least 1 gallon of water and be sure to add water daily. Research has shown that additives and water alternatives are not as effective as plain water in maintaining a tree through the holiday season.
Keep the tree away from sources of heat to reduce water consumption and help reduce fire hazards. Christmas trees rarely start fires in our homes, but they need to be watered to help them retain their color and keep your floor from getting too messy from fallen needles.
The fall is my favorite time of the year. I enjoy cooler weather, football season, and the amazing colors seen throughout our forested areas. Fall color can differ greatly from year to year depending on the weather, but there are plants we can add to our landscapes to give us reliable fall color, even in the years with less color variation or less intense fall colors.
How Fall Color Develops in our Trees
The color in our trees is due to four different pigments in the leaves: chlorophyll, carotene, tannin and anthocyanin. During the spring and summer, chlorophyll is the primary pigment in leaves. It is constantly being generated by the trees as it is easily broken down by bright sunlight. When this compound is being produced in the spring and summer, it is the most prevalent and that is why we see the green in the leaves. As the nights get cooler and the days get shorter, the tree produces a membrane between the branches and the leaves, causing them to no longer receive any chlorophyll that the tree might still be producing. This membrane also leads to the eventual shedding of the leaves in the fall. At this time, the other pigments 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. The cool, dry nights are also necessary 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. The yellow and brown will be present, but the red is necessary as well.
Carotene is the pigment that is responsible for yellow and orange colored leaves. Carotene is always in the leaves, as it aids in the capture of sunlight for photosynthesis, but it is at a lower amount than chlorophyll so green leaves appear.
Trees with high carotene in the fall for yellow or orange color include Shagbark Hickory as well as other hickories, birch, Redbud, and sugar maple. Serviceberry varies from yellow to orange to red. For shrub selections, choose witchhazel or spicebush.
Anthocyanin is the pigment that is responsible for pink, red, and purple leaves. This pigment is usually not present in the leaves until the fall. Some trees have red or purple colored leaves during the entire growing season because they have higher amounts of anthocyanins than chlorophyll throughout the whole growing season. Other trees don’t produce any anthocyanins and those are the trees that turn yellow, orange, or brown during the fall. Those trees and shrubs that turn red in the fall form anthocyanins when the concentration of sugar in the leaf increases. Low temperatures and bright sunshine destroys chlorophyll and when the temperatures stay above freezing during this time, anthocyanins are produced.
Trees with good red colors in the fall include scarlet oak, red maple, mountain ash, and sweetgum. For shrub selections, red fall color is found in burning bush, sumac, and some viburnums.
Tannins make brown colored leaves. Tannins are always present in leaves but are not shown until the other pigments have dissipated from the leaves. These often accumulate in dead leaves, which is why dead areas of our leaves turn brown in color. Brown is a good color for our fall color palette and should not be overlooked.
It is at this time of the year that I get questions asking if people should still be watering their plants or hear people say they just don’t need to water plants again until spring. However, it is very important to keep watering plants to ensure they go into the winter with a full reservoir of water in the soil to keep them alive and healthy through the winter.
The southeast portion of Nebraska is in the abnormally dry or moderate drought levels from the drought monitor. The drought monitor is determined by the USDA, NOAA and UNL to compare our current moisture levels to average moisture levels. You can follow it at https://droughtmonitor.unl.edu As we move into moderate drought, pasture and crop growth could be stunted and surface water levels begin to decline. This makes fall and winter watering extremely important, plants still need irrigation while they are dormant. If plants are ignored through drought conditions, it may seem that they are fine for a while but the dieback from drought stress can show up three to five years later. Also, drought stress can cause more damage from borers, canker disease, verticillium wilt, and other problems. Healthy plants can fight off pests better than stressed plants.
All plants will benefit from fall watering but make newly planted trees and shrubs and evergreens the priority. Use a soaker hose to ensure that the soil is wet down to 8-12 inches deep surrounding these plants and at least out to the dripline of those trees. Mulch can also help keep moisture near the plants, the goal is to keep the soil moist, not soggy or dry.
Winter watering is essential in dry years. Winter desiccation commonly occurs on evergreen trees and shrubs. All trees are still transpiring, or losing water, throughout the winter months, however, 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 on the ends of branches. However, the damage from winter desiccation does not usually show up in our trees until early spring. Drought can damage deciduous trees as well.
Ensure adequate watering throughout the entire growing season for all trees and shrubs, especially those recently planted. Water throughout the winter when the ground is not frozen, when necessary. Winter watering should occur during the day on days when the temperature is at least 40-45 degrees Fahrenheit 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, watering is not necessary. However, if pushing the screwdriver into the soil is very difficult, plants should be watered.
Anti-desiccant sprays, or anti-transpirants, help to reduce transpiration water loss from foliage. This can be especially helpful for evergreen trees during the winter months. Most of these products are an emulsion of wax, latex, or plastic to put a thin film on the foliage and reduce water loss. Plants such as arborvitae, pines, boxwoods, and others can benefit from using an anti-desiccant spray to protect them through the winter months. Anti-desiccants should be applied after late November, once they have completely hardened off. Do not apply these products too early in the year. They can be reapplied through the winter months or until mid to late February. Always read and follow the label for how to apply and how often to reapply.
This information came from the HortUpdate from UNL Extension.
It’s October, which means fall weather. With cooler weather, we may be going outside more to clean up our gardens or to spend time outdoors in the more enjoyable weather. However, some insects and arthropods may decide to crash our parties.
It’s still early October, but there is already a bug outside that thinks he or she is going to be a pirate for Halloween. The Minute Pirate Bug is active and it bites us in the fall months and it is quite a painful bite.
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 a black insect with white and black wings that grows to 1/8 inch in length. 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, working as 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 and they don’t come inside our homes. Insect repellents do not deter them because they are not attracted to us by carbon dioxide, so it is best just to wear long pants and a long-sleeved shirt to reduce areas for them to bite us.
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 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 mosquito bite.
Most people are concerned with brown recluse spiders. They are about the size of a quarter, legs and all and are brown with a darker brown fiddle shape on their back. They can cause a bad reaction in some people, but not all people are as sensitive to the bites as others. If you have brown recluse spiders in your home or office, just take the time to look around things that have been stored before you move them. These spiders are reclusive so they want to stay away from you.
Spiders are beneficial but not desired in a home. They feed on other insects in our homes. The best way to control a spider population indoors is to seal up all cracks and crevices in your home foundation and around windows and doors to reduce the amount of spiders moving inside. 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. Finally, sticky traps are a great way to manage spider populations indoors.
Fall officially started on September 22. We can see the end of summer gardening coming to a close. With that, we can get out to prepare our lawns and gardens for the winter months.
Summer bulbs bring great color and interest to our gardens, however, they do need to be dug up and stored indoors over the winter. Summer bulbs should be dug up prior to the first hard freeze in the fall. After the top growth has been killed by light frost in the fall, cut off the foliage and dig up the bulbs. Clean off the soil and allow the bulbs to dry for a couple of days prior to storage. Store summer bulbs in peat moss or sawdust in a well-ventilated, cool area for the winter months. Check periodically through the winter if more peat moss is needed.
Houseplants also should be brought back inside this time of the year to avoid injury due to the nighttime cold temperatures. Before bringing houseplants indoors, treat them with a general insecticide to ensure you do not bring any unwanted insect guests into your home. Leave outside for a day or two following insecticide use.
Cut back iris and peony plants as soon as the leaves start to turn brown in the fall. Remove all the foliage above ground and discard it to reduce the spread of diseases. Wait until early spring to cut back roses and butterfly bushes due to the hollow stem which can allow moisture into the stems to freeze and thaw through the winter. Native grasses and perennials can be cut back, if you choose. However, perennial plants can be left until the spring to give winter interest and to protect the plant over the winter.
With the end of the vegetable gardening season coming to an end, clean your garden space before winter. If a frost is predicted, be sure to harvest all you can from your garden prior to the frost. After the plants are finished for the season, clean the plants out of the garden and either compost them or discard them. If these plants had any diseases this year, it is best to not compost them. Also take the time this fall to till your garden to prepare for next spring. Add mulch to the soil after tilling to prevent wind erosion through the winter. Organic mulches, such as grass clippings, make a good mulch to use for this because it can then be tilled back into the garden in the spring, adding organic matter to the soil.
It may seem odd that I am writing about a Christmas plant now, but if you were one of those who kept your poinsettia alive all year, Great Job!! Also, now is the time to start the dark period for poinsettias to get them to rebloom.
Poinsettias will flower after being induced by a photoperiod. Starting at the end of September, place the poinsettia in a closet or cover it with a black cloth to keep it in total darkness from 5pm until 8am the next morning. Even the lights in our homes can interfere with the flowering cycle of this plant, so it needs to be completely dark around the plant. Once the flowers fully expand in mid-December, discontinue the dark period for the plant. Then, you can enjoy your poinsettia through the holiday season.
This is the Q&A for the Yard and Garden show for September 18, 2020. 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. The 2020 season of Yard and Garden is now completed.
Guest Host: Dr. Paul Read, Professor of Viticulture, UNL
1. The first question of the show was a listener who has oddly shaped potatoes. What causes them to grow in such odd shapes? Also, some of them sprouted new roots from the ground then arched over and planted itself down into the soil in the aisles between the rows. What caused that?
A. Potatoes are very receptive to fluctuations in moisture levels. With higher moisture the growth will rapidly increase and as we get drier, the growth will slow down. So with the high spring moisture followed by the summer heat and drought conditions, the potatoes grew oddly this year. As for the sprouting, remember that potatoes are underground stems, so it has the characteristics of a stem, including nodes. The potatoes likely went dormant in the heat and then sprouted when it cooled down again, causing those growths to come out of the ground and back into the ground. These potatoes will still be fine to eat.
She was also curious about mowing the lawn this fall. She wants to use the lawn mower to pick up the leaves from her tree. Should the mower height be lowered to do this?
A. No, we don’t recommend mowing short. It used to be recommended to mow shorter for the last mowing of the season to clean up the lawn. However, new research shows that it is better for the lawn to keep mowing at the same height all the time. Mowing short can expose the plant crowns making winterkill more common and can allow weeds to move into the lawn with little competition. It is best to maintain the 2.5-3.5 inch mowing height every time you mow.
2. This caller has a lilac that lost all the foliage and now is blooming. Will it die? Should anything be done to help it through?
A. The lilacs have been having troubles with a fungal leaf spot disease this year. It has caused the leaves to turn black and fall off, prematurely. In some cases, the leaves are regrowing now. It is not the correct time of the year to use a fungicide for this disease. For management, clean up the leaves at the end of the season once they have all fallen. Destroy those leaves. If you can, it would help to prune out one third of the largest branches now to increase airflow for the plant to reduce the disease next year. As for the blooming, that is weather induced. It won’t hurt the plant other than by reducing the amount of flowering next year because all the buds were set in the summer for flowering, those that bloomed now will not bloom again. There will still be some buds left to bloom next year. There is nothing that can be done to stop this process.
3. A caller has tomato plants, he was told to put copper on them because the bottom leaves are dying. What is causing this problem and will copper help? Also, are grubs in the garden a problem?
A. Copper fungicide will help with many fungal diseases in the garden. It is likely that the tomatoes got early blight in the early summer and it has been spreading through the plant since then. They may have also had a problem with Septoria, which was common this year. The copper fungicide will help, but I don’t think it would be necessary this late in the year, the growing season is nearly over. Fungicides don’t cure what is already infected, it will only reduce the spread, so at this point it isn’t necessary. Grubs can damage potatoes in the garden, but they typically don’t harm any other plants. The grub population has to be very high to be a concern in a garden.
4. This caller has a new house with an established asparagus patch. Should it be cut off now?
A. Cut the asparagus off either in the fall after it turns brown or early in the spring prior to the emergence of new spears.
5. A caller wondered if soil should be treated with some type of fungicide to help prevent soil-borne fungi from infecting her vegetable plants?
A. No, there are no soil treatments available to reduce fungi present. The best way to avoid soil-borne fungi is to rotate the crops from year to year to ensure that your plants are planted in the garden in the same spot every year. For best results, rotate crops by family, not just genus or species. Tomatoes, potatoes, peppers, and eggplants are all in the same family and cucumbers, pumpkins, squash, zucchini, melons, and gourds are in another family. These crops could be switched around but don’t put tomatoes where tomatoes or peppers were the previous year.
6. A listener from Fairbury brought in a sample of a cedar tree. The tips had turned brown and this has been affecting the plant since late spring or early summer. These are cedars in a windbreak. What caused this?
A. Because this happened to the ends of the branches this spring, it is likely due to the weather. We had snow and very cold temperatures in May just as the new growth was starting on the cedars. This weather caused a winterkill condition to the new growth. The cedars should be fine next year.
7. When should a yucca plant be moved?
A. Yucca plants have a very deep tap root, which will make it difficult to move at any time. Anytime now should be good for transplanting it, be sure to get as much of the roots as you can. A listener called in later to say he has had good success moving yucca in the spring. Just avoid the hot part of the summer and it should be fine.
8. This caller has a very small garden that makes it difficult to really rotate his crops. What can he do to ensure that he is rotating as much as he can? Would it be best to take a year off of growing tomatoes, for example?
A. It might be beneficial for the overall health of the soils and the plants in the garden to opt out of a certain crop each year. Maybe one year plant the whole garden to sweet corn. If you do want to do this, you could try some container plantings of other vegetables you enjoy. There are a lot of new “patio” varieties of many of our favorite vegetable plants. They are made to grow small in a container on a patio.
9. A caller has a lot of crabgrass in her lawn. What can she do to control it and not lose her full lawn?
A. This late in the season, it wouldn’t be effective to treat the crabgrass. Crabgrass is a summer annual so it will die with the first frost, which likely won’t be too far away. Use a pre-emergence herbicide on the lawn next spring to stop it before it grows next year. Typically, this is applied around the end of April. A second application in June will help to get season-long control of crabgrass and other summer annual, grassy weeds. Then, next fall, she can overseed the lawn to thicken it up. This would be best done in late August to early September. This year it is getting quite late to overseed the lawn. If we get cold weather very soon, that new grass would have problems with frost damage or winterkill.
10. The final caller of the season asked if he should cut his pampas grass off or if he should burn it off?
A. Cut it off. If you burn a plant off, such as pampas grass, it can get too hot at the crown and kill the plant. Also, this can start a house or garage fire depending on where the grass is planted and how close it is to buildings. Grasses should be left to stand through the winter months for winter interest, wildlife habitat, and to protect the crown of the plant through the winter months. It should be cut off next spring prior to new growth. When you do cut the pampas grass off, it would help to tie a rope of some kind around the grass to help with easier cleanup.
*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.
Thanks to everyone for listening to Yard and Garden in 2020 or to those of you who read my blog from the shows! Join us in the spring of 2021 for more episodes!
This is the Q&A for the Yard and Garden show for September 11, 2020. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am, this is the first fall episode ever. It can also be found on kutt995.com for online listening. Join us online for the last show of the season next week, September 18, 2020. 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: Kyle Koch, Extension Educator and Insect Diagnostician
1. The first question of the show was a listener who has raspberries that are not growing well. Is it the heat?
A. Fruits are the expert area of the guest who will be on the show next week, Dr. Paul Read, it would be best if you can call back when he is on the show to get the best answer and methods of managing your raspberries.
2. This caller has grown squash plants for many years. This year the plants died within 2 days from being healthy. He didn’t notice any damage from squash bugs or squash vine borer. What would cause this?
A. If squash vine borer damage was not noticed, I would suspect cucumber wilt virus. Both squash vine borers will cause the plants to wilt almost overnight, but the damage will be seen at the base of each plant. If not from the borers, cucumber beetles can spread a disease called cucumber wilt virus that will also cause the plants to die very quickly. These are small, yellow-green colored beetles with black spots, similar to a small, green ladybeetle. Once a squash vine borer is in the plant it is very difficult to save the plant. If it has the virus, there is no cure, the plant needs to be removed to reduce the spread to other plants. You should also spray insecticides on the other plants to keep the beetles and squash vine borer off the plant. Even if you did spray, it is not always effective in preventing a virus because the insect has to feed on the plant to die from the insecticide and can spread the virus before being killed.
3. A caller has blue spruce trees that are planted too close to some older spruce. The new spruce were planted to replace the older, dying spruce trees. He has called earlier in the year and it was determined that the trees had needle cast disease. What can he do to control that disease?
A. For Needle cast disease, it is not effective to spray with fungicides now, but next spring they can be treated with chlorothalonil. They should be sprayed when the new needles are half expanded and then again 4 weeks later when the needles are fully expanded.
4. This caller has a squash plant that has grown from her compost pile. It has developed a white squash with green ridges, a very unusual squash. Can this be eaten?
A. This would be the result of cross pollination that occurred last year. Many people are concerned about planting pumpkins and squash too close together because they are worried that the pumpkin won’t develop correctly. Cross pollination affects the seed of what develops this year, so in pumpkins and squash it won’t affect the look of the produce from this seasons’ produce. If you save seed from year to year, the next season the produce may look a little different. Because this is showing up in the compost pile, means that cross pollination happened in her garden last year or with the pumpkins she purchased for fall or Halloween decorations. I don’t know what it is or what it will taste like, but it should be ok to be eaten, it may not taste quite like you think it will or like anything very good. The other point with this situation is that her compost pile is likely not being managed correctly. If something grows from it, those parts of the pile are not breaking down correctly. Be sure to turn it often and monitor the temperature and moisture level.
5. This caller has pin oak branches that are drooping over the sidewalk making it difficult to walk under the tree. Can she prune those branches off now?
A. Fall is a good time to prune oak trees, it is best to avoid pruning oak trees during the growing season to avoid damage from oak wilt. Oak wilt is a disease that is spread by a beetle that is attracted to trees that have been injured or were recently pruned, so it is best to avoid pruning them during the growing season while the beetle is active. It is best to wait until they are starting or in their dormancy period, November or later through the winter months.
6. When can you transplant walking onions?
A. These onions are divided when you take the above ground bulb and divide the pieces to transplant them to a new location. Wait until the bulb dries out then you can remove it and plant the pieces somewhere else.
7. This caller has a lilac that has died at the bottom and now has new leaves at the top of the plant. The leaves on the top of the plant turned brown and dropped leaves recently but they are regrowing. What is wrong with it?
A. The lilacs have been having troubles with a fungal leaf spot disease this year. It has caused the leaves to turn black and fall off, prematurely. In some cases, the leaves are regrowing now. It is not the correct time of the year to use a fungicide for this disease. For management, clean up the leaves at the end of the season once they have all fallen. Destroy those leaves. If you can, it would help to prune out some of the largest branches now to increase airflow for the plant to reduce the disease next year.
8. A caller sent a photo of an insect that he wanted identified. He found it on his tree.
A. This is a jewel beetle. It is not harmful and does not need to be controlled with an insecticide.
9. The final call of the show was from someone who wanted to know when you can transplant peonies?
A. Now. You can transplant peonies in the early fall, September and early October are great. You can cut it back when you move them. Be sure to plant them at the same depth as they are planted currently because if they are too deep they will not bloom.
*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.
*The photo of Row covers above is from Jody Green, Extension Educator
The weather this week has been quite unusual. When we get temperatures this low we begin to think about fall and what we need to do with our gardens. There are ways to extend the season if you would like to do that, otherwise, cleaning up your garden is best when it has finished producing.
September 8th is very early for such cold weather. Parts of northern Nebraska had a frost this week and we were very close to that. Due to this early onset of more typical fall weather, we might see an early frost this year. Typically for southeast Nebraska, the first frost date is October 6-16. This is just an average and it can happen sooner, however this early for a frost would be very rare.
Row covers are a way to extend the growing season through a light frost. Row covers are made of a light, spun fabric that you can see through. The row covers just sit on top of the plants to add a slight level of protection against freezing temperatures. The material is lightweight so it does not damage the plants as it rests on them. The typical row covers give you 2-8 degrees of protection from frost situation. For example, if the plant can withstand 32 degrees without a row cover, it can remain alive and growing through temperatures as low as 24 degrees with the row cover.
*This information came from John Porter, Nebraska Extension Educator.
A cold frame is described by Missouri Extension as “a protected plant bed with no artificial heat added”. This is a good way to keep plants protected a little longer into the fall. Build a box frame out of lumber with a glass or plexiglass cover. This box is then placed over plants to increase the temperature and avoid damaging frosts. A Cold frame is a good way to recycle old windows or doors. The frame can even be made as simply as using hay bales for the sides and a window in the center. A cold frame can also be used in the spring to harden off any plants that you grow from seed indoors or to get an early start on cool season crops.
When you have finished harvesting from your garden or when it quits producing, you need to clean up the garden space for winter. If any of your plants had disease or insect issues this summer, it is best to remove those plants and destroy them, don’t compost them. This will reduce the chance of seeing the problem again next year. Also, removing the plants from the garden at the end of the season will remove the overwintering site for insects found in the garden. Cleaning tomato cages and fences upon removal will also help remove the disease spores from the garden for next year.
After removing the plants, you may want to till your garden. If you plan to add fresh manure to your garden, that should be done in the fall when you till your garden. After tilling this fall, be sure to add a layer of mulch to the garden to keep the soil from blowing off site during the winter. Grass clippings without any type of herbicides on them would be a good mulch for the winter because you can till that right into the soil next spring before planting again.
It’s nearly September which means fall weather will soon be here. Also, September and October are great months to plant a tree. We can now start thinking about what trees we want to plant and where to plant them.
How to Plant a Tree
Health and longevity of the tree starts with good planting practices. First, remove the tree from the container and remove all wraps and ropes around the rootball, including the burlap. Next, shake off the excess soil and find the main rootball. The area where the lateral roots begin should be just below the soil surface. After you have determined the actual size of the rootball, dig a hole twice as wide and only as deep as the roots. Do not loosen the soil in the bottom of the planting hole or the tree will settle lower and then be too deep in the ground. Backfill into the hole with the soil that was removed when digging the hole to avoid creating a wall that roots cannot penetrate from one soil type to another. Add a mulch ring to all trees. The ring should be 2-3 inches deep and at least 2-3 feet wide around the tree. Trees can be staked if necessary but the staking equipment should only be left on for one growing season.
After planting, be sure to water the tree right away and keep it watered for the first few years. When we are not receiving rain, water new trees weekly for 15-20 minutes per application. Once the weather starts to cool down this fall, this watering can be done every 2 weeks. As the tree grows, it will need to be watered for 30-45 minutes and up to one hour on the same weekly and biweekly schedule.
Where to Plant a Tree
When planting your trees, remember to pay close attention to where you plant it to ensure that the tree can have a long life. Often when we plant a tree, it is hard to visualize the full size of a tree, but remember, that small tree will grow into a much larger version. Plant the tree where it can spread its branches and grow to full size and think about what is around the tree. Consider overhead power lines, underground utilities, current buildings, any future construction that is planned, sidewalks, and the mature size of the tree.
Prior to planting call the Digger’s Hotline at 811 to ensure there are no underground utilities near the planting location. Remember, that the tree roots will grow, it would be best to give your tree plenty of space to grow without becoming too close to the power lines to avoid future problems with the roots and the lines. Calling the Digger’s Hotline will also help so you don’t run into underground utility lines while you are planting. Never assume that the utility lines are deeper than you plan to dig.
Also, look at the above ground structures when you plant a new tree. Plant large trees at least 20 feet from a building to avoid damage to the building as the plant grows. Plant trees 25 feet away from overhead power lines to avoid damage to the lines and to help the crews of our electrical companies from having to send a crew out to prune the trees in the lines. Smaller, understory trees should be used under power lines to help the men and women who work for our electric company.