This is the Q&A for the Yard and Garden show for April 6, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 3, 2018. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.
Guest Hosts: Jonathan Larson, Douglas/Sarpy County Extension Educator in Entomology and Jody Green, Lancaster County Extension Educator in Entomology
1.The first caller of the show has little blue flowers in her lawn. How can she get rid of them?
A. This is likely speedwell, it is a winter annual plant so it blooms very early in the spring then dies with warmer weather. At this point, since it is already blooming, just leave it as it will die soon and the seed is already set for next year. Spray it with a 2,4-D product late next fall after it has germinated or use a pre-emergent herbicide in the earlier fall before it germinates.
2. What is the correct mowing height?
A. 2.5-3.5 inches is the recommended mowing height for cool season turf in Nebraska. Too low will lead to more weed pressure and insect and disease issues because the turf cannot compete with these pests when it is too short. Make sure you mow enough to mow off only 1/3 of the turf blade each time you mow to avoid scalping the turf.
3. A caller asked if the treatments for Emerald Ash Borer (EAB) were killing the trees?
A. The most effective treatment methods for EAB are trunk injections, which can harm the tree. However, the tree can take about 10 treatments before stressing the tree to the point of death. If you are using Emamectin benzoate as the trunk injection chemical, the tree will only need to be treated every 2-3 years, giving it 20-30 years of injections before harm occurs. For the first few years of treatments, you may be able to use a soil drench rather than a trunk injection, again adding more time with your tree. A soil drench will work, but once the tree grows to 15-20 Diameter, the soil drench is not as effective. In the 20-30 years of treatments, you can get a very good start on a new tree nearby the ash tree to have a well-established tree growing in it’s place for when the ash tree needs to be removed.
4. Does wood mulch attract termites?
A. If the wood mulch is piled up so high to where the mulch is touching wood siding, it can be a pathway for the termites to enter the home. However, mulch is recommended to only be 2-3 inches deep and most concrete foundations will go higher than that. Also, if you have had termites in the past, you should be working with a pest control company for termite control and the chemicals will manage the termites from the mulch. You will not get termites from mulch, the mulch is cut up too small and termites will dry out in that condition, so that cannot happen.
5. This caller is replanting a windbreak. They have begun with an outside row of cedars and would like to know what to plant on the interior rows?
A. An interior row with multiple types of trees is best. Diversity will help your windbreak survive better if another disease or insect problem comes in to kill evergreen trees like pine wilt has. Good evergreen choices include blue spruce, black hills spruce, concolor fir, Douglas fir, ponderosa pine, white pine, and Norway spruce. You can even add in deciduous trees like oaks or maples to fill in as well.
6. A caller wants to know how to control poison hemlock on the edge of his field?
A. 2,4-D and Dicamba in a mix. This mixture is found in the product called Trimec as well as others. It is best to treat the poison hemlock while it is in the rosette stage, so early spring or fall. Do not allow cattle access to the dry matter after this has been sprayed.
7. This caller wants to know if fertilizer is needed to trees as they plant a new windbreak?
A. Fertilizer is not necessary for trees planted in Nebraska. Our soils typically have plenty of nutrients available for use by the trees. It wouldn’t hurt to add fertilizer at planting, but it isn’t necessary.
8. The final caller of the day wants to know how to plant a new asparagus patch?
A. Asparagus is a great plant for a home garden. Many people want to get plant starts from a neighbor to start their patch, but it is best to just purchase a new set of crowns. When planting asparagus crowns, dig a trench 8-12 inches deep and bury the crowns only under 2 inches of soil. As the plants poke up through the soil, add more soil until the soil is level. Avoid harvesting asparagus until the third season of growth to allow the crowns enough time for root production. For weed control, mulch is best, such as wood chips or grass clippings. Preen that is labeled for use around asparagus can be used in the spring to prevent annual weeds from germinating. In late May to early June, when finished harvesting asparagus for the year, you can break all the spears off below ground, leaving no green growth above ground, and spray glyphosate or Roundup over the bed to reduce weeds. After this, allow the plants to grow back up and produce ferns which will produce seed and help your patch grow. You can cut it back in the fall or in the spring before new growth begins.