Q. My Chinese hollies, English boxwood and Andromeda (Pieris aponical) all look like they are dead or dying. I suppose it was the cold weather. Is there any reason for hope they will recover?
A. Wait to see the severity of the damage before you do anything, says Dr. Paul L. Smeal, Virginia Tech specialist. There may still be life in the stems and branches but you won't know how far back the plants are killed until new growth begins. The plants may even die back to the ground but the roots could still he alive and put out new growth. Later on, the extent of die-back can be determined and the dead wood removed. At the same time, fertilize generously to stimulate new growth.
Q. We dug up our lawn and seeded it with Kentucky bluebrass. Now we have a lot of tiny weeds. Where did they all come from? Could there have been weed seeds in with the grass seeds?
A. In many, perhaps most, soils there are quantities of weed seeds buried a few inches deep, waiting for someone to dig them to the surface where they can get light enough to germinate. Your digging up the lawn probably did just that.
The seeds come in by air, water, animals and man's devices. They accumulate in the soil and stay alive for years.
What can be done about it? There is no really easy way at this point. Sterilizing the soil to a depth of several inches could destroy a lot of weed seeds but that could be a difficult undertaking.
Q. I planted two paper birch trees on our front lawn last spring mainly because my wife loves them. I've been told recently these trees are short lived because of borers. Is this true?
A. The natural range of the paper birch is the northern United States and Canada. South of its natural range it is likely to be attacked by bronze birch borers.
The damage done by the borer is first apparent when the top of the tree suddenly wilts and dies. The borers work from the top of the tree down and when borer holes appear in the trunk it is usually too late to save the tree.
One way to help your birch trees is to try to keep them in the best possible health.Prune all dead and dying wood; fertilize the trees in late fall after they become dormant; water the trees regularly during dry weather in the summer; and spray during spring and summer of destroy the beetles which lay the eggs which produce the borers.
Q. The brick pavement of my patio is almost covered with moss. I am removing it with a putty knife and wire brush but at great cost in labor and stiff back. Is there a better way to remove it, a chemical perhaps?
A. The moss can be burned off with ammonium sulfate, a high-nitrogen fertilizer. Wet the moss and sprinkle the fertilizer over it. Then use a wire brush to brush away the dead roots.
Q. I want to plant a ligustrum hedge on one side of our yard to separate the yard from the vegetable garden. My husband thinks it might damage what will grow next to the ligustrum-corn, cabbage or beans. Do you think it would?
A. The only damage it would do would be shading the vegetables, otherwise no problem.
Q. Does it pay to sucker sweet corn?
A. Research has shown on many occasions that suckering sweet corn in not necessary.
Q. What can I use on cabbage to control worms? They start eating them before they head.
A. Cabbage and realted crucifels may be attacked by diamondback moth worms, imported cabbage worms and cabbage loopers. Bacillus thurin giensis, sold under the trade names of Dipel, Thurieide and Biotrol, is a safe microbial insecticide that can be used to control all three species of these worms. Directions on the label should be followed closely.
Q. What vegetables might grow best in pots on the patio?
A. With full sunlight, tomatoes, radishes, peppers, chives and most of the leafy greens, can be grown. Cherry tomatoes are the best kind to use.