The March Gardener

March can be a transitional month for the gardener.

Daylight Saving Time begins on March 11 and Spring begins on March 20. This means more daylight time to work in the garden and a gradual increase in the average daily temperatures.

I’ve already ordered several new plants from an on-line nursery that are scheduled to arrive at the end of this month.

I can hardly wait to get my hands in the soil.

Lawns: It's not a good idea to apply fertilizer to cool season turf in the spring unless your turf is weak and thin or you did not fertilize this past fall. Fertilizing in the spring encourages rapid succulent growth that is more susceptible to attack by insects and disease.

I know I’ve mentioned this before and it doesn’t hurt to mention it again: Spring is a good time too have your soil tested. Keeping the soil pH in the 6.0 – 7.0 range is very important in maintaining healthy turf. A soil test will determine its pH and the amount of lime needed.

Agricultural limestone (ground or dolomitic) can be applied to raise soil pH. Pelletized lime is slightly more expensive than ground limestone but is easier to apply. Not sure how to take a soil sample? Go to the University of Marylnd Home and Garden Information Center website and watch their video on collecting a soil sample.

If you had crabgrass last year, consider applying a pre-emergent herbicide later this month. If you are also re-seeding, be sure to select an herbicide labeled for use on new lawns.

The best prevention for crabgrass and other weeds is to improve the lawn and keep it mowed regularly at the proper height (2-3 inches for cool season grasses).

Woody Ornamentals: Prune non-flowering trees and shrubs before new growth and when the worst of the winter weather is over. Remove branches broken by winter weather, prune out dead or diseased branches anytime and make any necessary cosmetic cuts. Do not prune spring-blooming shrubs such as azaleas, rhododendrons and forsythia until after they are finished blooming.

Roses can be pruned starting in mid-March to maintain their shape and size. Roses always have some winter kill. To determine whether or not a branch is alive, simply scrape the bark with a sharp knife and look for green tissue.

“Knock Out” roses do not require as much pruning as hybrid tea roses. Simply cut the canes back every year in late winter or early spring to approximately 24 inches. Cutting them back very severely is not recommended. They won’t die but will require a long time to recover.

Indoor Plants: Now is a good time to begin re-potting and dividing houseplants that are outgrowing their containers. Don’t jump pot sizes from a small pot to a very large pot. Moving to a too large pot will make the plant much more prone to overwatering damage. Do not use garden soil. Use lightweight soilless potting mixes containing peat moss, vermiculite and perlite.

Herbaceous Ornamental Plants: Cut down perennials and overwintering ornamental grasses to within 2 inches of the ground and remove plant debris from flower beds. It’s also a good time to divide your perennials as they start to emerge from the soil.

Pat Cieslak
Master Gardener, Baltimore County
University of Maryland Extension
Questions? Visit the Home and Garden Information Center or call 1-800-342-2507, Mon.-Fri., 8 a.m.-1 p.m.