March Gardening Tasks
Expand the categories below to learn more about what you need to do this month.
Vegetables
Before setting them in the garden, harden-off transplants by placing them outdoors a few days to a week ahead of anticipated planting. Continue planting the spring garden – onions, cabbage, carrots, lettuce, spinach, mustard and turnips. Now is the time to set out herb transplants like cilantro, chives, sage, rosemary, thyme, and parsley. Sow dill directly in the garden. Continue growing warm-weather transplants such as tomatoes, peppers, and eggplants to transplant in mid-to-late April.
Fruit Trees
Apply dormant oil to fruit plantings in early March to reduce scale and mite insects. Make a fungicide application to control peach leaf curl. Finish pruning fruit trees, grapes, raspberries, and blackberries. Be prepared for late frosts on blooming blueberries and strawberries and have frost-protective covers ready.
Lawns
It’s time for an application of nitrogen for Bermuda grass lawns that have been overseeded with ryegrass for the winter. Follow the recommendations on your soil test report for your lawn. In the absence of a soil test report, for overseeded rye, apply 2 pounds of urea (46-0-0) or better, 6 lbs of calcium nitrate (15.5-0-0), per 1000 sf. If you have tall fescue, you can now apply 3 lbs of urea or 9 pounds of calcium nitrate per 1000 sf.
DON'T fertilize Bermuda, zoysia, centipede or St. Augustine yet – wait until greenup. If you fertilize warm season grasses too early, you can still get winter kill. It is highly likely after a winter with temperatures below 15 degrees, that you will see some winterkill in St. Augustine in south Hall County and in centipede as well. Winterkill will probably also be seen in bermudagrass where temperatures dropped below 10 degrees or so.
Forsythia bushes bloom just before crabgrass germinates and are a visual hint to apply pre-emergent herbicides. Temperatures must generally remain at 50 to 51 and up to 55 to 60 degrees F for roughly four days to trigger germination. Sunny lawns, southern exposures, burned lawns or lawn bordering sun-warmed patios or sidewalks warm up earlier than the rest of the yard. Be certain if you apply pre-emergent herbicides for crabgrass control, that you get it in before the soil starts warming.
Spot spray for dandelions, henbit, and chickweed. Early March to the middle of the month is the latest time to apply a spring pre-emergent herbicide for crabgrass. You might do this again as a follow-up in May into June.
Flowers
Clean up the perennial bed by cutting back foliage and removing winter mulch layer. If early in the month, it’s not too late to divide and plant perennials in the garden. If dry, prepare soil for planting by adding compost or other organic matter. Start seeds indoors under lights for transplanting to the garden. Plant new roses. Fertilize spring flowering bulbs such as tulips and daffodils. Cut seed pods from spent bulbs. Help control iris borers by destroying old foliage before new growth begins. Unwrap mail order plants immediately and keep them cool and moist until planting.
When the soil is consistently above 55-65 degrees to 4-5 inches, you can start to plant things like gladiolus, dahlia, canna, amaryllis, lilies and gloriosa lily bulbs for spring and summer flowering in beds that have been amended with organic matter. Provide stakes as needed to support growth.
Dianthus, pansies, viola, ornamental cabbage and kale, and dusty miller and other cool-season annuals will continue to flourish as long as the days continue to be cool (less than 80-85 degrees).
Trees
Trees you’ll see in bloom this month include red maples, flowering cherries, the invasive royal paulownia, Bradford pears and wild plums. Flowering quince should be in full bloom by late February and early into March.
Mulch tree and shrub plantings up to 4 inches deep, keeping mulch away from trunks. Fertilize established trees and shrubs. Plant new trees and shrubs in the landscape.
Prune trees as needed, and repair winter storm damage. Topping is not pruning, so never top a tree. Especially, don’t top crape myrtles! Early March is still a good time to prune your repeat-blooming roses such as floribunda and hybrid tea roses, if you haven’t already done this by late February. Do not prune your once-flowering climbing roses now, but instead prune them after the bloom.
If azaleas or rhododendrons need hard pruning to shape or produce a fuller plant, do it just after plants finish blooming.
Don’t prune cold-damaged plants yet. Wait until consistent warm weather returns to cut back plants.
Houseplants
This is a good time to re-pot and divide houseplants. Use lightweight, well-drained soil-less potting mixes containing peat moss, vermiculite and perlite. If a houseplant is already in a very large container and you cannot move it up to a larger one, you can remove the plant and prune its roots. Fill the outside with fresh potting medium. Pruning some of the roots may set the plant back a little but it will recover and it will have more space for the roots and improve pot drainage.
Continue monitoring for and controlling indoor houseplant pests!
Miscellaneous
Sharpen tools and lawn mower blades.
Now is a good time to inspect your irrigation system for repairs and upgrades. You should also review your automatic timer's manual to re-familiarize yourself with how to set times.