University of Vermont Extension 
Department of Plant and Soil Science

Spring News Article

Charlie Nardozzi, Senior Horticulturist
National Gardening Association, and
Dr. Leonard Perry, Extension Professor
University of Vermont

Testing your soil, potting summer bulbs, and planting peas are some of the gardening activities for this month.

Dahlias, cannas, and gladiolus are available now and you can get a head start by potting them up indoors. Plant them in large containers and keep them in a cool room, if possible, in a sunny window until planting time outside. Dahlias may need to be pinched back while still indoors to keep the plants from getting leggy. You'll get earlier blooms with this technique.

Remove the old stalks from ornamental grasses before new growth begins or you'll cut off new growth when you prune. For large plants, you may need to use hedge trimmers or a pruning saw. Cut to several inches above the crown. It helps to tie the stalks together before you cut.

If you have pets or neighbor cats and dogs that like to visit your gardens, take steps now to deter them. There are products you can sprinkle around the beds that safely repel animals, low fences that you can set up around beds, and gadgets such as pointed plastic spikes you can lay in popular digging spots. It's easier to deter bad habits than to break them.

Since butterfly bushes (if hardy in your area) bloom on new growth, the best time to prune is early spring before new growth begins. Cut off the old stalks to within a few inches of the ground. If you want a more compact plant, also pinch off the tips of the branches in early May. If you wait too long, you'll remove flower buds.

Once the soil reaches 45 degrees and is dried out enough to dig in, it's time to plant peas. Choose a location in full sun and orient the rows north-south to take full advantage of the sunlight. Turn over the soil with a garden fork, or rototill if it's a new bed. Soak the seeds for a few hours or overnight (no longer or they may rot), and dust the seeds with an inoculant of nitrogen-fixing bacteria to help the roots take in more nitrogen. Set up your trellis first, then plant the seeds 1 to 2 inches deep. Cultivate very shallowly because the roots grow close to the surface; better yet, pull the weeds by hand so you don't accidentally cut off a plant.

Now is a good time to dig and divide late-blooming perennials, such as asters and daylilies, when they begin emerging from the soil surface. Dig up the clump, and use a sharp spade to create pie-shaped wedges. Replant these divisions in a full-sun location in well-drained soil, and water often to keep soil moderately moist.

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. At the very least test the pH, which you can do yourself with an easy-to-use home kit.  You can find them at many garden stores.  Make sure the kits are new this year, as the chemicals can go bad over time.  The proper soil pH is especially important for plant health.

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