Ask a Master Gardener: Deformed asparagus and best tree, bush planting times

Q: Can I still apply lime and other fertilizers to a cool season lawn? We're supposed to get our soil test result back this week and are concerned we might be too late.

A: Yes, you can still apply lime and other nutrients. Our standard recommendation is to apply nitrogen fertilizer in September and again in November. If one of those are missed, then fertilize with it again in April. Lime takes up to six months to fully react, so applying in the fall is ideal. By the time the grass gets growing, it should have had the desired effect.

Potassium, phosphorus and calcium required will be provided with the soil test. These should be applied this November as well. Letting grass clippings return into the lawn thatch (not bagging and removing them) will reduce fertilizer requirements, especially of phosphorus, potassium and calcium.

Q: I have had such lousy luck with trees on my ground, which is very heavy clay. Someone told me once to mound up the soil 6-8 inches and plant them "high." Is that true? Can I plant any tree then?

A: I advise mounding the soil up 6-8 inches for most tree plantings where there is some clay. Where clay is extreme, the mound would be much greater than that, 1-2 feet, depending on the size of the root ball. In these situations, only the bottom of the root ball is planted below grade. The rest of it is covered by creating a mound about three times the diameter of the root ball width. MU Extension has a publication that goes into detail and provides drawings: extension.missouri.edu/p/G6955 (Improving Lawn and Landscape Soils).

Given the clay is very heavy, seek out trees that will adapt. A reputable list of trees can be found at Missouri Botanic Garden under the tab "Problem Solver Plants for Clay Soils - Trees." The easiest way to get there is to do an internet search on "Missouri Botanical Garden - Plants for Clay Soils - Trees." The list contained more than 30 trees and many are common and desirable.

Q: Is this a good time to plant bushes or trees? What about if they are evergreens?

A: November is a good time, but the selection available may be less. Missouri's winters are generally mild enough so the soil doesn't freeze very deeply and often doesn't stay frozen for extended periods. This allows for that root ball to not freeze and the roots can grow some until spring. It is a good idea to protect it by mulching two to three inches deep.

For evergreens, it is a little trickier, as they need to be watered through cold dry spells because their leaves continue to transpire. Some people are willing to do this or have a situation where it is easier to get the hose out and use it when cold. So I advise against planting evergreens unless really willing to make that effort. Applying a product like WiltPruf or wrapping an evergreen with burlap (for the winter) can also help.

Q: My asparagus dried up earlier than usual and are a very dark gray color, not the usual yellowish straw color. The new growth is deformed, with the main stem curling and leafy stuff grows tight to stalk. What might it be and what should be done?

A: There are three common diseases for asparagus. The description of the ferns prematurely browning/dying down for the season match rust symptoms the closest. Rust is also described as having a blackish color later in the season. Rust on the stems can cause some twisting.

The remedy for it is "reduce crop residues by removing, mowing or burning of old ferns in the fall/winter." You might want to get rid of the old mulch (as it likely has frond residue in it) prior to spear emergence in the spring; this should reduce infection. Add fresh mulch after next spring's harvest season.