University of Vermont Extension 
Department of Plant and Soil Science

Spring News Article
Charlie Nardozzi, Horticulturist and
Leonard Perry, UVM Extension Horticulturist
Hardening off seedlings before planting outside, checking for tent caterpillars, and reseeding lawns are some of the gardening tips for this month.
Be sure to harden off indoor-grown seedlings before setting them into the garden. Acclimate plants to outdoor conditions over the course of at least a week, and preferably two, by gradually increasing the amount of time you leave them outdoors.  This includes both exposure to cooler temperatures and sunlight.  Put them in the shade for a few days to adjust to the brighter sun outdoors.  Plunging them directly from indoors into the full sun often causes sunburn—a rapid bleaching and dying of foliage.
If you've taken advantage of this early spring by planting your container gardens already, be sure to protect them from a spring frost by moving them indoors on chilly nights or covering them with a floating row cover.
If you haven’t planted containers yet, consider adding a water absorbing product (sold as this in garden stores) to the soil first.  You only need a little (follow label directions), with the result being you’ll need to water less often as plants grow.  This kind of addition is especially useful in hanging baskets that tend to dry out quickly.
Check apple, cherry, and other fruit trees for nests of tent caterpillars. Blast low-lying nests with water to destroy them, or knock them to the ground and destroy them. A spray of Bt will kill emerging caterpillars but is not toxic to beneficial insects, birds, or humans.
If you want to move some spring-blooming bulbs to another spot, wait until the foliage has turned yellow, then carefully dig them up and let them dry in a shady spot for a few days. Store the bulbs in a cool, dry place for the summer until it's time to plant them in fall. Or you can replant them then and allow the foliage to continue to die back.  This is needed for nutrients to go from the leaves back into the bulbs for the coming season.  Don’t have a place to plant them yet?  Then you can “heel” them in, planting in a shallow trench, or pot them for holding.
When you transplant annual flowers and veggies, don't try to loosen the root balls. With such a small root mass, a plant is easily set back if many roots are damaged.   With only a summer in which to grow, these plants need to hit the ground running with no delays.
Before reseeding bare spots in the lawn, spread 1 to 2 inches of compost over the areas and firm it down. Then sow grass seed. Sprinkle a thin layer of compost on top of the seed, cover with straw and keep it moist. If you have pets, encircle the spots with stakes and tie string around them to deter pets.
Reduce the weeds in walkways in your garden by covering the soil with some type of mulch. Some people like to use carpet scraps placed upside-down. Several sheets of moistened newspaper topped with hay or straw works very well, especially if you move your planting areas around a bit from year to year. Try to avoid tilling to remove weeds because the process brings up weed seeds from deeper in the soil and exposes them to the light they need to grow.
Other tips for this month include fencing pest animals out of gardens, staking tomatoes while young, and keeping lawns mowed regularly yet not too low (3 inches high is often good).
(Charlie Nardozzi is a nationally known horticulturist, author, gardening consultant, and garden coach; 

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