Q: Was the groundhog right this year? Spring seems late.
A: Yes! Punxsutawney Phil predicted winter sticking around for six weeks after Feb. 2. Ironically, more than five weeks later on March 11, I watched snowflakes almost of size of badminton birdies the morning waft down. So he got it right, which he generally does, half the time. Spring is slightly late; last year's was early. The mild February was followed by a cold spell in mid-March, which frosted may fruit tree blossoms. This year looks better; a consistent and gradual warming is easier on many plants.
Q: I have trouble with squash bugs. How do they overwinter and can I do anything to prevent them?
A: They overwinter as large adults, crawling into plant residue. While they might favor crop residue of a prior crop like pumpkin, they can go off to a wooded area, pasture or something similar. For larger areas like a "field" tilling, the soil in the fall can reduce their overwintering population. This can have some benefit for home gardens, as well as moving a squash patch to a new location that is somewhat removed from the prior one. You could still till as well as locate a planting somewhere else.
Quickly applying a synthetic insecticide, labeled to control "stink bugs," as soon as you see the adults is one of the most effective ways to control them. The first ones are females ready to lay eggs. An insecticide application may not kill the adults, but it should control the nymphs hatching from the eggs, as they are more sensitive.
Q: I got crabgrass in an area last year and now there isn't much grass. How can I prevent it and still seed new grass?
A: You'll want to reseed ASAP. First take up all the residue you can by vigorously raking by hand, or if the area is large, use a machine like a dethatcher. Next spread your grass seed, lightly rake in, and spread a thin layer of straw (1-2 inches and one bale can cover up to 1,000 square feet). While we usually get enough rains in the spring to keep the area moist, water if needed, especially if the temperatures are good for grass emergence (50s-70s). The straw is extremely helpful for keeping moisture at the surface.
You can't use a granular crabgrass preventer until this new grass is well established, about 3 inches tall. While this might be after the preferred window (April 1-15), crabgrass germinates well into the summer, so it will still be helpful. There are post emergent crabgrass killers one can spray, which should be effective through May. Read and follow any pesticide label.
Q: Can you tell me a good (hopefully relatively inexpensive but effective) way to kill and prevent bagworm infestations of Juniper and Blue Spruce pine trees in my yard?
A: Applying an insecticide in the spring as soon as the eggs hatch and small larvae begin emerging from the overwintering bag is the most effective; this is late May to mid-June. So an insecticide treatment about May 20 and another about June 10 should provide excellent results. Chemical control becomes less effective as the season progresses because of the increased size of the larva and its bag.
Dipel or Thuricide uses a natural product (BT) that is fairly effective and another good natural product is Fertilome Borer, Bagworm Leafminer and Tent Caterpillar Killer. Another easy to find and good product is Spectracide Triazide Insect Killer, which is sometimes sold in a ready to use spray bottle. If mixing your own spray solution, be sure to add a spreader sticker, which can be purchased. You can also substitute 1/16 teaspoon of dish soap (e.g. dawn). Add this after you fill the container with water to prevent uncontrolled foaming. Read and follow any pesticide label.
Q: I saw mulch piled up around a tree and wondered if that is a good idea.
A: That is referred to as a "mulch volcano." Arborists and other garden professionals roundly trash the technique, which seemed to gain popularity in the 2000s around the Midwest. It can become very matted, causing water to flow off and restricting air exchange. It can also promote bark decay at the base of the tree; bark likes to be dry and exposed to light. Mulch should be spread at a uniform depth at about 3 inches deep, at which it reduces weeds, conserves moisture, allows air exchange, and builds organic matter. For more details, see University of Illinois 'Gardener's Corner' Volume 7, Issue 3.