University of Vermont Extension 
Department of Plant and Soil Science

Spring News Article
line
CHECKING VIBURNUMS AND OTHER APRIL GARDENING TIPS
 
Charlie Nardozzi, Senior Horticulturist
National Gardening Association, and
Dr. Leonard Perry, Extension Professor
University of Vermont
 
 
Checking viburnum shrubs for leaf beetle eggs, preparing flower planters, and potting dahlia tubers are some of the garden tips for this month.

If your viburnums had problems with viburnum leaf beetles last summer, now is the time to inspect your plants closely for egg-laying sites on the bark.  Look for tiny, brownish black bumps on your twigs.  These are the coverings over holes in which the eggs are laid.  Prune these infested twigs as soon as possible because the eggs will be hatching soon and the young larvae will begin feeding on new foliage.

Check strawberry plants twice a week for signs of new growth. As soon as you see sprouts, remove the hay or straw mulch and spread it in the rows to help control weeds. A topdressing of an inch or two of compost will give plants a boost.

It's a good idea to test your soil every few years to determine its nutrient status and pH (acidity/alkalinity). Your state extension service can provide a reasonably priced test, and along with the results you'll get recommendations for improving the soil. The proper soil pH is especially important for plant health.

When planting large containers for the deck or patio, save on soil by creating a false bottom. Most of the plants you'll use don't need more than about a foot of soil depth for their roots, so put some foam packing peanuts in the very bottom, then cover with landscape fabric or a piece of cardboard cut to fit to keep the soil from sifting around the peanuts. Or use small plastic pots to take up some space before filling the planter with soil.

Get flowers sooner by potting up dahlia tubers and growing them indoors until it's warm enough to plant them outside. Pinch the growing tips when they get six inches tall to keep the growth short and stocky for easier transplanting into the garden.

To get a head-start on fresh greens, sow seeds in a large, shallow container. Keep the container outside during the day and bring it in at night if the temperatures dip below freezing, or protect it in a cold frame.

Don’t be in too much of a rush to prune roses and other woody perennials.   If butterfly bush has died to the ground, cut the dead stems to the ground. Otherwise just shorten them by about one third. Cut back Russian sage, rue, and artemisias to about 8 to 12 inches from the ground. Don't prune lavender until new growth appears, and then just shorten the stems by about one-third. Heather should be lightly pruned to remove the old flowers and the tips of the shoots, but don't cut back to brown wood, stay in the green.   


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