This is the Q&A for the Yard and Garden show for July 5, 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: Laurie Stepanek, Forest Health Management Specialist from the Nebraska Forest Service
1. The first question of the show was curious about bagworms. He needs to spray the trees in his backyard but he has a coy pond nearby. Will the sprays harm the fish in the pond?
A. It would be best to use Bt on the bagworms here to ensure that if sprays get into the pond it will not harm the fish. Bt is a product that affects only butterflies and moths and won’t harm other insects or wildlife. Bt works best on young, newly emerged bagworms, but there would still be time for that product this year.
2. A caller has willow trees that are growing on a dam for a pond. How can they be controlled?
A. Rodeo or Garlon 3A are the 2 products listed for managing woody plants or annual and perennial weeds in or around water in the Weed Management Guide from Nebraska Extension.
3. This caller has garden plants that were chewed off by rabbits. Will these plants regrow or are they dead?
A. If there are still a few leaves left on the plant they might still regrow. However, if there is really only a stem and a tiny leaf or two, they likely won’t regrow. It is getting quite late for replanting, so it might be best to just wait and see how they regrow.
4. A caller has an apple tree that broke off at a split in the tree in a storm. Now there is a hole in the tree. What can be sprayed or put into that hole to prevent further damage?
A. It is not recommended to fill holes in the tree because that can be harmful when the tree does need to be removed. It also will not stop decay that is occurring in the tree. Decay is a fungus and it will proceed through the tree even around a fill agent. If the decay is a problem in the tree, the tree may need to be removed before it becomes a hazard.
This caller also has a maple with dead branches in the top of the canopy. What would cause that?
A. Top dieback could come from a number of factors. It could be from a canker disease that occurs on stressed trees. Canker diseases will kill branches from the point of infection outward on the branch. The only cure for a canker would be to cut out the branch below the canker. Top dieback could also be from borers or a root issue. Borers come into a stressed tree and will cause decreased flow of water and nutrients through the tree causing the top of the branches to die. If more soil is added to roots, causing decreased airflow to the roots, top dieback can occur. Root issues such as damage to the roots or a girdled root can also cause top dieback in the tree. Root issues cannot be fixed. If you notice borer holes, you can use a systemic insecticide containing Imidacloprid, such as Merit.
5. A walk-in listener wants help with identification of a weedy grass species that he is having trouble controlling.
A. This looks to be annual bluegrass, which can be difficult to control. Use pre-emergent herbicides such as Drive or Pendulum in September or use Tenacity as a post-emergent herbicide in the spring or summer. For more information, view this Turf iNfo on Annual Bluegrass Control.
6. This caller has maple trees that have limbs reaching out over his house, some of the limbs are dead. When and how far should these limbs be pruned to ensure they don’t fall on the house and cause problems?
A. It would be best to find a Certified Arborist to do this to ensure it is done correctly and to avoid damage to the house. Remove all dead branches. When shortening branches, cut back to a side branch that is at least 1/2 the size of the limb you are removing. Anytime would be ok, but the best time for a maple is later in the spring, to avoid heavy sap flow if pruned in the early spring or late winter.
7. A caller accidentally spilled hydraulic oil from his tractor onto his lawn. There is now a dead area in the soil. What is a quicker way to get grass growing back there other than to wait?
A. It might help to dig out the soil in that area and replace it with new topsoil. Dig out around the area of dead grass and dig 4-6 inches deep. It would be best to just wait until early September to do this so that it can be reseeded right away.
8. This caller wants to use Roundup around the base of fruit trees to kill grass. Should regular Roundup be used or could Extended Control Roundup be used?
A. Use basic Roundup that only contains glyphosate in this location. The Extended Control Roundup contains Imazapic for longer control and shouldn’t be used around fruits and vegetables. The label for the Extended Control Roundup states ‘Do not use for vegetable garden preparation or in and around fruits and vegetables’. Always read and follow labels of pesticides.
This caller also wanted to know what is wrong with her apricot trees, the fruits seem to be rotting as they fall from the tree?
A. This is likely due to brown rot. Next year, use orchard fruit tree sprays through the growing season. The orchard fruit sprays should be used every 10-14 days through the growing season, except during the bloom period and when ready to harvest.
9. The last caller of the day wants to know if he can eat the fruits off a purple leaf sand cherry? Also, can he shear it or is it too old to start that now that it is 5-6 years old and hasn’t been sheared yet?
A. The berries are not eaten from purple leaf sand cherry, this plant is more for ornamental value. These fruits are scavenged by birds instead. This is also a plant that won’t grow well if sheared. It is best to just selectively remove branches back to side-shoots to reduce the size.
*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.