University of Vermont Extension 
Department of Plant and Soil Science

Spring News Article


Charlie Nardozzi, Horticulturist and
Leonard Perry, UVM Extension Horticulturist
Proper mulching, watching for tent caterpillars, and planting vegetables are some of the many gardening activities for this month.
When spreading bark mulch around trees, be sure to remove the old mulch first and not spread the mulch against the tree trunk. You should only have a 2- inch thick layer of mulch around the tree so roots can breathe. Mulch piled against the tree trunk (called “volcano” mulching after its appearance) can lead to crown rot and eventual death of your tree. Use the old mulch in compost, or spread on flower and shrub beds.  It is already partially broken down, and as it continues will add organic matter to soils. 

Check apple, cherry, and other fruit trees for nests of tent caterpillars. They will emerge as the leaves do to feed. Blast low lying nests with water to destroy them or spray Bt on emerging caterpillars. Bt will harm only the caterpillars and not other beneficial insects, birds or humans.

While checking fruit trees, look for signs of fireblight, especially on pears and apples.  The infected tips of branches will be dark, shriveled, and with leaves still clinging from last year. They look like someone torched them with fire.   Prune out infected shoots, then disinfect your pruners with a chlorine bleach solution (one part bleach to 9 parts water).

It's vegetable planting time in most of the area. In valleys and warm areas plant tomatoes, peppers, beans, lettuce, squash, and cucumbers the end of the month.  Many like to plant around Memorial Day. In colder areas you may want to wait until early June to plant these heat lovers as well as watermelon, okra, and eggplant. Plant them too early before the air and ground warms up, and they won’t grow, and may even rot.

Flowers are a bit more forgiving than warm-season vegetables if planted out early and the spring is cool.  Just have some frost protection ready, just in case.  A heavier weight “frost blanket” provides a couple degrees more frost protection than a lighter weight.

Young seedlings just sprouting such as lettuce, beets, and carrots need a consistent supply of water now so they don't dry out and die. Once germination starts, it can't be stopped, so if the weather turns warm and dry, water these seeded beds every day.

Tomatoes produce and grow best when staked or caged to keep the plants off the ground. Place these supports when you put transplants into the ground so you don't disturb the root systems by installing them later. Caged plants can grow freely, but use large cages made from concrete-reinforcing wire to support them.  If using tomato cages or wide wire mesh such as from fencing, make sure to hold it up with 2 or 3 stakes so the heavy plants wont topple later.

Make sure if you have rabbits and deer and groundhogs that your plants are safe.  If you plant in a discrete area, you can fence it with 2-foot high chicken wire for low mammals.  Just make sure the wire mesh is either partially buried or anchored to the ground.  For deer you’ll need taller fencing, perhaps 4 feet for a small area but up to 8 feet for large areas.  The lower height often works if a small bed, as they’re afraid of jumping in and getting trapped.  Of course there are many repellents you can buy or make and spray onto individual shrubs and flowers.

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