March is the month people inquire about their gardening problems.
E-mail is the most efficient method of communicating with pictures of insects or diseases which can help determine the problem and provide solutions. Below are questions similar to those you may have.
Q: When can I prune my azaleas? We have large plants that need to be pruned.
A: Normally, pruning is recommended after the bloom in early June.
Q: What is that purple weed in my yard and how do I control it?
A: The weed is either henbit or deadnettle, both related to each other. Post emergence herbicides such as Trimec or Weed-B-Gon will control the weed, but during flowering, the weed is difficult to kill.
Q: I sprayed my weeds last week and they are not dying. What is the problem?
A: Blooming broadleaf winter annuals are difficult and may be impossible to kill because they are in the process of producing seed and not growing and therefore not adsorbing herbicides. Weeds should look distorted and withered a few days after application. Two applications of broad-leafed herbicides 10 days apart is an effective solution. Blooming annuals now will be dead in a few weeks as the temperature increases.
Q: Can I over-seed my lawn now?
A: Fescue can be over-seeded now, especially bare spots. Don’t wait too late in the spring.
Q: Is it too late to apply pre-emergence herbicides to lawns?
A: No, now is the time to apply pre-emergence herbicides. As the soil warms, crabgrass and goosegrass germinate, making pre-emergence herbicides useless.
Q: My squash plants do well in the summer and produce well. Then after a few weeks they wilt and die almost overnight. What can be the problem?
A: Sounds much like squash vine borers. Once borers have gained entrance into stems, little control is possible, so early detection is critical. Some gardeners cut the grub out with a sharp knife and the plant will continue to bear. Since the insect passes the winter in the ground, squash should not follow squash. Land should be disked in the fall to expose the cocoons and then plowed deeply the following spring. Vines should always be destroyed following harvest to prevent late caterpillars from completing their development.
Q: Is it too late to mow my liriope?
A: No, liriope is a lily and a tough plant. Cold weather has held it back this winter. Make sure your mower blade is sharp.
Darrell Blackwelder is an agricultural agent in charge of horticulture with the North Carolina Cooperative Extension Service in Rowan County. Call 704-216-8970 or visit http://www.rowanmastergardener.com; http://rowan.ces.ncsu.edu; http://rowanhorticulture.blogspot.com/