March Garden Tips

March Tips

March has somewhat fickle weather, making it impossible to set dates and schedules for planting, so proceed with caution!

March is the month when many of the beautiful spring flowering perennials begin to flower.  Aubrietia, Candytuft, Rock Cress, Bergenia, Snowdrops, Witch-hazel and many others will be brightening your days.  With spring just around the corner, it is time to get serious and get the garden ready.  Prepare the soil for planting as long as it is workable and get a soil test.

Indoor Plants

  • Wait until the weather warms to start putting houseplants outside.
  • Repot houseplants that have grown too large for their containers.  Cut back leggy plants to encourage compact growth. Root the cuttings in moist media to increase your supply of plants.
  • Houseplants can be watered more frequently with the onset of spring and new growth.
  • Start fertilizing houseplants now for good growth.  Any that are root bound should be repotted.

Lawns and Landscaping

  • Early spring is the right time for two special turf treatments, if needed; vertical cutting or thinning to remove thatch and aerification or coring to reduce soil compaction.  Special equipment is available for each operation.  Consult a lawn-care specialist, or rent the equipment and do it yourself.
  • Reposition stepping stones that have heaved or sunk below grass level.  Lift them up, spread sand in the low areas, and replace the rocks.  A bed of sand under the stones will aid drainage and decrease heaving next year.
  • When a blanket of snow insulates the lawn, temperatures a ground level may rise to above freezing.  Snow mold fungi (a white, cottony growth on grass blades) thrives at temperatures between 32 and 65 degrees F.  To reduce possible snow mold damage, remove heavy snow accumulations in shady areas.  If you cannot physically remove the snow, spread ashes or dry peat moss on the snow.  The dark-colored material will absorb solar radiation and melt the snow faster.
  • Apply a pre-emergent herbicide before lawn weeds get started.  These chemicals work by preventing seed from germinating.  Therefore, it is important that the herbicides be applied in early spring, before growth of the weed seedlings.  Check with the Extension Office agent for specific recommendations.
  • Use crabgrass killer before forsythia blooms fade.
  • Variegated plants can help add the illusion of light to a dark area.  Shade-loving ground covers, such as variegated liriope, ivies, euonymous and hosta, can be very effective for this.
  • Shrubs and trees in home landscape break up sound waves of modern society.  Plant some new shrubs and trees this spring to improve the beauty and ambience of your home.

Perennials, Annuals and Bulbs

  • Bluebells are superb for naturalizing in the same manner as daffodils, but prefer shadier locations, and will bloom even where they get no direct sun at all.
  • Impatiens, one of the best annuals for shady spots, start looming three months from seeding.  Start seeds indoors now, and they'll be ready to set out after the last frost date (avg. for this area 4/10-4/21).  Pinch back seedlings once or twice before setting out to promote compact, bushy plants.
  • If weeds occur in bulb beds, do not remove them by cultivation.  Pull them by hand so the bulbs and roots will not be disturbed.
  • Some annuals, such as verbenas, snapdragons and petunias, take 70 to 90 days to bloom.  They should be started indoors in early spring or purchased as greenhouse-grown transplants.
  • Rejuvenate your liriope by using a lawn mower to cut back the old foliage to height of 2 to 3 inches.  Avoid mowing too close and damaging the crown of the plant since that is where the new growth emerges.
  • Hostas, liriope, daylilies, dicentra, Shasta daisies and coral bells are some perennials that can be divided and transplanted before growth starts in spring.
  • Don't forget to fertilize naturalized bulbs in the spring as leaves emerge.  Do not mow the area until the bulb foliage begins to die back.
  • When buying transplants, choose those plants with a compact, bushy form and bright-green leaves.  Young, healthy plants with no flowers or flower buds will adapt more easily and overcome the shock of planting much faster.

Trees, Shrubs and Groundcovers

  • A good rule of thumb for planting rhododendrons is; the smaller the leaf (i.e., R. carolinianum, R. laetivirens), the more tolerant it is of winter sunlight.  Large-leaved rhododendrons, such as R. catawbiense or R. maximum, have more winter injury when planted in bright locations.
  • When transplanting a young shade tree, it may help to orient the tree in its new location the same way it was in its old home.  This will prevent previously shaded bark from suddenly being exposed to afternoon sun and causing injury.  When not possible or desirable, or if the original orientation is unknown, wrap the trunk in tree tape or coat the sunny sides with white, exterior latex paint for one growing season.
  • Some nurseries are still using that brown plastic material that looks and feels like natural burlap.  This material will not break down in the soil and should be completely removed before transplanting a shrub or tree.
  • If you are buying bare-root trees, look for ones with a large root system in relation to the top growth.  It is not necessary to purchase a very large tree to get a quality plant.
  • Once new growth begins on trees and shrubs, cut back winter-killed twigs to living, green wood.
  • For more compact pyracanthas without the risk of losing berries, pinch back new growth now.
  • Prune evergreen shrubs before growth starts.
  • Prune spring-flowering shrubs after flowering is completed.
  • Boxwoods should be pruned by thinning the outer foliage of the plants and cutting back the branches to retain desired height.
  • Plant roses and bare-root shrubs while they are still dormant, about 4 weeks before the average date of the last frost.
  • Hedges can receive their first pruning this month.  As you prune, be sure to leave the base of the plant wider than the top.  This allows sunlight to get to the bottom of the plant, creating a full dense hedge.
  • Dogwoods and magnolias should only be moved in early spring.  Always move magnolias with ball of dirt.
  • Propagate deciduous shrubs, such as forsynthia and winter jasmine, now by ground layering.
  • Pruning should never be done in damp or wet weather when the fungal spores and bacteria that infect plants through fresh wounds spread easily.
  • Trees that bleed, such as birch and maple, should not be pruned until their leaves are fully developed.
  • Fertilize established roses after pruning.  It is wise to have your soil tested about every 2 years.  If black spot or powdery mildew has been a problem, contact the Extension Office for recommended fungicides.
  • When pruning or cutting roses, cut all flower stems 1/4 inch above a complete (5 leaflet) leaf, leaving two complete leaves below the cut bud.  Always use sharp, pruning shears and cut on a slant.


  • Start transplants indoors of tomatoes, peppers and eggplant.
  • Parsley is rich in vitamins A and C.  Start some seeds indoors now for later transplanting to a sunny corner of the vegetable garden.
  • Pick a permanent spot for herbs in the garden.  Many of them will come up year after year.
  • As soon as soil can be worked, plant potatoes, peas, onion sets, leeks and other cool weather crops, including beets, Chinese cabbage, kale mustard and turnips.
  • Sow more seeds of spinach, lettuce, arugula and other salad greens in cold frames or in the vegetable bed, under row covers.
  • Put up trellises and teepees for peas, pole beans and other climbers.

Tools and Equipment

  • Protect yourself and the blade of your pruning saw during storage.  Make a cover for it using a piece of old garden hose the same length as the blade.  Cut the hose lengthwise on one side, and place it over the saw blade.
  • Ice cream scoops are great for digging holes for transplants; the dirt slides off easily.
  • If you haven't done it already, check stored tools and outdoor furniture for signs of rust.  Remove any surface rust with steel wool, and paint with rust-inhibitive paint.


  • Containers from the kitchen can be recycled for starting seeds.  Aluminum trays from frozen food just need a few holes to provide drainage.  Other possibilities are cottage cheese containers, milk or ice cream cartons, Styrofoam egg cartons, or paper cups.  All should have drainage holes.
  • Make your own potting mix for outdoor container with one part rich productive garden soil, I part leaf mold or compost, and 1 part builders sand or perlite.  Add 1 tablespoon dry, 5-10-5 fertilizer and 1 tablespoon dolomitic lime per gallon of mixture.
  • Don't buy more chemicals than you can use in a season--the smaller the bottle, the better.  If you overbought in the past and have aged, garden chemicals you no longer use, dispose of them according to local regulations.  Do not pour them down the drain or onto the ground as this can pollute water systems, damage the soil and possibly injure or kill plants, people and animals that come in contact with the chemicals.
  • In your flower arrangements, avoid mixing cut daffodils with tulips.  Daffodils produce a chemical "slime" that injures tulip blooms.  If you wish to use the two in an arrangement, place the daffodils in another container for a day after cutting, then rinse off the stems and add to the vase of tulips.  Adding 1 tablespoon of activated charcoal or 6 drops of bleach to each quart of water also helps.
  • Mulches can change the soil temperature.  Black plastic warms the soil and should be applied before planting.  Organic materials delay the sun's penetration thereby keeping the soil cooler.  Apply organic mulches after plants are 3 to 4 inches tall and the soil is warm.
  • Cover old stumps with soil to hasten decay.
  • Place bird houses outdoors early this month.  Birds will begin looking for nesting sites soon, and the houses should attract several mating pairs.
  • Don't overexert those under worked, winter muscles as you begin your spring gardening.  Bend at the knees and lift with your legs, not your back.
  • When setting out transplants in peat pots, be careful not to allow the rim of the pot to protrude above the soil level.  It will act as a wick and draw moisture up from the plant.  Break away the upper rim of the pot before planting, and make sure none of the peat shows above the soil.

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