University of Vermont Extension 
Department of Plant and Soil Science

Winter News Article

PRUNING AND OTHER MARCH GARDENING TIPS

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

Pruning trees and shrubs, cutting back ornamental grasses, and checking perennials for frost heaving are some of the gardening tips for this month.

The days are longer, the sun is warmer, and sooner or later the buds of trees and shrubs will start growing. Best to finish pruning just in case winter suddenly releases its grip. Remove dead, diseased, and rubbing branches, and do any thinning needed to open up a tree canopy to more air and sunlight. Cut broken branches back to a main branch or the trunk rather than leaving stubs. Wound sealer generally isn't necessary.  Wait to prune spring-flowering shrubs until right after bloom.  Wait to prune maples and birches until after they leaf out, otherwise their rising sap will run or "bleed" from open wounds.
           
Before the new shoots emerge, cut back last year's stalks of ornamental grasses. Hand pruners will do the job for small plants, but electric hedge trimmers make quick work of large specimens with dense growth. If possible, chop the stalks before adding them to the compost pile or using them as mulch so they will decompose more quickly.

Cut back upright grasses such as feather reed grass, switchgrass, moor grass and miscanthus.  Don't cut back too far, only 15 to 24 inches above the soil surface, otherwise you may cut off some of this season's growing points buried in stems.  Only cut back old flower stalks from mounded grasses such as blue oat grass and blue fescues, leaving their mounds of foliage.  Pull off any old dead, loose and brown leaves.  Every few years blue fescues should be dug up and replanted as they tend to rise up over time and get bare bases.

Take a walk around your yard to check for perennials that may have heaved out of the ground, exposing their roots to drying winds. Gently tamp them back into the soil or if the soil is too frozen, surround them with mulch as protection, tamping down later.
           
When the temperature climbs to 50 degrees in early spring and the wind is low, move houseplants with scale or mealybugs outdoors to a shady spot and thoroughly coat the foliage with lightweight or summer oil. Then move the plants back inside. A forceful stream of water, repeated every week as needed, may be all that is needed to dislodge mealybugs.  Check areas where leaves join stems for the white fluffy masses of the mealybugs.  Check undersides of leaves for brown scales, or their smaller light-colored crawling stage.
           
Cabbage, broccoli, and other cole crops that can be set out in early spring all can be started this month.  Sow slow-growing flowers such as pansies, begonias, and vinca early in the month.  Sow verbena, petunias, geranium, and impatiens later in the month.  But wait until April to sow seeds for tomatoes, peppers, eggplants, and most flower varieties that cannot be transplanted until the danger of frost is past.  Check on the seed packet to see if seeds can be started indoors, or should be sown directly in the ground when the weather warms up. 
            
Other tips for this month include stocking up on your gardening supplies, visiting a maple sugarhouse or tapping your own maples, and taking your mowers in for tune-ups.
            

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