Yard and Garden: March 24, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for March 24, 2017. 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 July 28, 2017. 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: Cole Thompson, Assistant Professor of Integrated Turfgrass Management at UNL

1. The first question of the year was a caller who had 2 peach trees that were three years old when they died last year. He cut the trees off and now there is suckers coming up from the ground where those trees were. Will these trees grow and produce peaches?

A. These trees will grow and will most likely produce fruit. However, they will not be a strong growth and the peaches produced may not be the variety that he originally planted. Many of our fruit trees are grafted to a hardier rootstock. If they die back or produce suckers, that growth will be the type of tree that the roots are not the type that the scion, or top part of the graft union, was. Also, because it is from a sucker, it is not going to grow as strong and upright as the main tree. He can try to keep them going but it would be best to plant new trees as well, if he has the space for both, he can keep both the suckers and new trees. If he only had room for a couple of trees, I would suggest starting the trees over from new trees.

2015-06-25 10.19.56

*Reference to commercial products or trade names is made with the understanding that no discrimination is intended of those not mentioned and no endorsement by University of Nebraska–Lincoln Extension is implied for those mentioned.

2. This caller wanted to know what the difference is between Roundup and Roundup 365?

A. Roundup 365 contains a chemical called imazapic which gives the traditional glyphosate product more of a soil residual. The Roundup 365 is labeled only for use on and around hardscape areas such as patios, gravel paths, and driveways. The label claims that it lasts in the soil for up to 12 months, so it should not be used around trees, shrubs, or areas you plan to reseed. Regular Roundup can be used in an area around plants and where you plan to seed after the recommended wait time. You would need to be much more careful with the Roundup 365 because of the soil residual around other plants.

3. A caller has pussy willow branches that were brought indoors and placed in water to begin rooting. They have now developed roots. Can they be planted outdoors now?

A. Yes, as long as the roots have begun to form and the ground can be worked, it would be fine to plant them outdoors now.

4. When is the best time to reseed a Fescue lawn in Southeast Nebraska?

A. Fall is the best time to reseed a lawn, but it can also be done fairly effectively in the spring. It is harder in the spring due to the weeds that compete with the grass seedlings. If you plan to reseed in the spring, it is best to wait until late April to early May for that. If you seed earlier in April, increase the seeding rate to compensate for the loss due to the colder temperatures. When you seed, you can apply tenacity or a mesotrione product to the seedbed to help with weeds. Tenacity is safe for use at seeding. It is also a good idea to seed with a starter fertilizer to help get your seed started strong.

5. This caller has a birch that was cut down last fall. The remaining stump is oozing a lot of liquid right now. How do they kill the birch entirely to stop the liquid from oozing out of the stump.

A. Birch trees are one of the species of trees that tend to “Bleed” heavily in the spring if they are pruned. They have a high sap flow in the spring which will lead to the oozing of large amounts of sap through any open wounds. On a normal pruning cut to a tree with high sap flow, it is not harmful to the tree. This tree still has living roots and the wound from cutting it off is exposed so the sap still will flow through. This tree either needs to be treated with chemicals to kill it or the stump needs to be ground out to stop this sap flow and to be able to plant new plants in the area. You can drill new holes into the tree and apply 2,4-D to those holes to start to kill the tree. With chemicals, it will take a few years to fully kill the stump.

6. Can raspberries be transplanted now?

A. Yes, raspberries should be planted as early as the ground can be worked in the spring, so now would be fine. It is best if the soil was prepared last year by spraying all the weeds and incorporating organic matter. This will help to ensure you have a raspberry planting to last many years.

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7. A caller planted grass last fall and held the seed to the seedbed with a biodegradable plastic barrier designed for seeding turf. However, now the plastic is not breaking down and it is getting stuck in the lawnmower. Is there anything they can do to break it down quicker? It will disturb the lawn too much to try to pull it out now.

A. Pulling it out without disturbing the lawn would be the quickest, but if that is not safe to do without tearing up the lawn, that isn’t the best option. Try to water it down or hope for rain, the moisture may help to break it down faster than it sitting dry. This winter was quite dry which may have delayed the breaking down process.

8. This caller had a giant tree fall in his yard. He has removed most of the tree but about 5 feet of the trunk is still standing in the yard. What can he do with the stump?

A. It would be best to cut that trunk off at the ground level and grind the stump out so that you can replant either with turf or with a new tree. If you don’t want to grind it out now or replant, you can cut it down to the ground level and place soil over it to allow it to naturally break down under the soil.

9. A caller has been growing watermelons but they tend to wither and die early in the year. What is wrong and how can he improve his crop?

A. It sounds like this caller has squash vine borers that get into his vines in the summer months. Squash vine borer is a type of moth larvae that gets into the stem of the vines and blocks the movement of water and nutrients through the plant. They are very common in melons, squash, cucumbers, and pumpkins. To avoid the damage from this insect, use a spray or dust formulation of sevin or eight on the base of the plant regularly through the growing season starting in June. You can also use aluminum foil or a toilet paper tube around the base of the plant to act as a barrier between the plant and the female squash vine borer adult who is trying to lay her eggs on the plant.

10. This caller has 25 bur oak trees that were planted 4 feet apart with the idea that some would die to space them out further. Most did not die and are still planted too closely. Will they grow that close together or should some be removed?

A. Bur oaks grow quite large, but in a forested area they will grow fairly close together. They will grow this closely together, however it will shade out many of the branches and it will cause conditions that are conducive to diseases when trees don’t have the space to have good airflow. It would be best to remove some of the trees so that the trees left behind are given 20 feet or more between them. They are only 10-12 feet tall at this time so they would still be fine to be spaded out and transplanted to another location if you can find someone to spade them and someone to plant them somewhere else.

11. Is it too early to plant onions? Is it time to cut back mums that are left from last fall?

A. Late March to early April is the best time to plant onions. Wait to cut back perennials from last fall. The dead plant material will protect them from freezing temperatures for another week or two. The plant material can be removed in the beginning to the middle of April.

12. This caller has a yard with high dog traffic. What type of grass would be best to stay growing through the dog traffic?

A. High traffic lawns will decline. Increasing the fertility will improve growth in this area. Also, if you could limit the traffic patterns from time to time through the lawn, this would help as well. Kentucky Bluegrass will recover better in high traffic areas.

13. A caller has a bean field area that he is trying to turn back to a grass area. What type of grass would do good in this area for an non-irrigated recreational area on an acreage?

A. Buffalograss would be great for an acreage area. Once it becomes established it wouldn’t have to be irrigated much or mowed at all. It is a very low maintenance grass species that is native and you can choose many different newer varieties. UNL has good seed selections. Because this was a bean field it might be over-tilled so a roller may be necessary to firm the soil up before planting. Buffalograss is a warm season grass so it should be seeded May 1st.

14. The final caller of the day has an established cedar windbreak. Some of the trees were removed recently and there is a bare area in the nearby trees where they were shaded out from the removed trees. This area is only 7 feet from the house. What can be planted in place of these trees to help block the bare area in the windbreak?

A. Because this is so close to the house, don’t go with anything too big. A larger shrub may be a good choice such as a viburnum, serviceberry, some dogwoods or even some lilacs may help fill in. Some slender growing trees may also work, but full size trees may grow into the house.

Henbit?!

Henbit from canva

It’s spring, finally! I know our winter wasn’t terrible this year, but I always look forward to spring. That is such an exciting time of the year, all of our plants are greening up and the early blooming trees, shrubs, and bulbs are beginning to show us their beauty for the year. However, not everything about spring is fun and games. This is the time of the year I always get calls about that dreaded purple flowering weed in our lawns and gardens.

Henbit is the purple blooming weed that shows its ugly face very early in the spring. This is the weed that will cover crop fields early in the spring with large expanses of purple blossoms. This weed is also quite prevalent in our lawns and gardens.

henbit, steve dewey, Utah State Univ, Bugwood

Henbit is a member of the mint family, which means that it has square stems. It has leaves that are rounded with a scalloped edge and they are arranged oppositely along the stem. It has a small purple flower with darker colored purple spots on the lower petals of the flowers. Henbit is often confused with creeping Charlie or ground ivy, which is a perennial weed from the same family with purple colored flowers as well. The differences between the two are that creeping Charlie is a perennial so it blooms later in the year than henbit and creeping Charlie has flowers that are more blue and henbit flowers are more purple.

Henbit is a winter annual. This means that henbit only lives for one growing season, but it’s development is different from something like crabgrass which is a summer annual. A winter annual is a plant that germinates in the fall and grows a bit before basically becoming dormant for the winter months. Very early in the spring, henbit will start to grow again, produce flowers which produce seed for the growth to come next year and then it dies. A winter annual dies as soon as the weather starts to warm up in the late spring whereas a summer annual germinates in the spring and goes through it’s lifecycle through the summer months, dying with our fall frosts.

The problem with henbit is that by the time we see it, or rather see the beautiful purple flowers, it is too late to treat it this year. As I said, henbit dies when the weather warms up, so why spray it with a chemical when it is going to die in a few weeks anyway. The fact that it is noticed when it is blooming shows us that it is already producing seed for next year, so killing the existing plants does nothing for the future generation of this plant. However, pulling the plant would be a fine management practice in the spring months.

Henbit is a plant that tends to grow in the areas where grass typically dies out. Areas around sidewalks and driveways or areas where people tend to cut the corner around sidewalks are locations where the turf gets worn down and the henbit excels. Henbit is also often found along the foundation of a house or in a garden area with exposed soils. If we can do things to keep your grass growing in these locations or use other plants or mulch to cover the bare soil, the henbit will struggle. Using a pre-emergent herbicide for broadleaf weeds in the fall will also help reduce the seed germination. Finally, using any broadleaf post-emergent herbicide later in the fall after the henbit has germinated, such as 2,4-D, will kill henbit as well.

Nebraska Weather Effects on Plants

Crazy Weather blog

This year the weather has been crazy. We saw 70’s in February followed by 30’s and snow in the middle of March. The warm weather was great, but it got all of us in the mood for spring, including our plants. Now that we have seen such a cool down, our plants may be the ones most affected.

We have seen early budding in many of our shade trees and shrubs, which often happens with above average winter and spring temperatures. This can be problematic for the plant. If the swelling or opening up of buds occurs prior to a cold snap, it can cause damage to that particular bud. If those buds that were opening up were flower buds, we may lose the flowers on that shrub or tree for the year. However, if those buds were leaf buds, those plants may be set back on their emergence and growth for the year. If leaf buds were damaged, a healthy tree will set new, secondary buds to push growth but it will be later in the season than normal. As long as the tree is healthy it will be fine. But, there is nothing you can do to stop this condition.

Red maple, bugwood

Photo from: Chris Evans, Illinois Wildlife Action Plan, Bugwood.org

This warm up, cool down cycle is stressful to our plants. So, it is a good idea to help keep your plants otherwise healthy. Make sure your trees and shrubs are properly mulched and kept well watered in the absence of rain.

Another issue that we are dealing with this spring with the rapidly changing environment, is the advanced emergence from dormancy of spring bulbs prior to this latest cold snap. There is nothing you can do regarding this issue either. The bulbs that have already begun to bloom may lose their flowers early or have some freeze damage. These bulbs may also experience some leaf dieback. Tulips and daffodils are normally a spring blooming plant, so they are accustomed to normal spring freezes adapting to temperatures as low as the upper 20’s. However, if we see anything lower than that, these plants may exhibit freeze damage on the leaves, showing up as white, limp leaves. Do not cut back the damaged leaves until the foliage dies back on its own.

Finally, we have started to see many of our perennial plants emerging and greening up for the spring already. Much of this growth occurred before the cold snap last week. As for these plants, I would advise you to just leave them alone. If there is a forecast for very low temperatures, it would benefit the plants to add additional mulch or a row cover over them for the overnight hours, pulling that back during the day as the temperatures warm up. If you didn’t remove the plant material last fall, leave it there now until the spring, even as they green up below it. If you expose the crown of the plant that has been covered by the dead plant material all winter long, cold snaps will be more problematic for the plants. The dead plant material and extra mulch the plant has had over the winter months will protect it from freezing and thawing and from very cold temperatures this late in the season. It is best to wait until we are more consistently facing spring weather before removing this plant blanket they have had all winter.