It’s official! Wherever you live, March 20 is the first day of Spring. Now, I didn’t say it would be warm or frost-free, but still…Spring! In many gardens, things are already popping up all over the place, so it’s time to get ready for those long gardening days that are just around the corner. Wherever you live and garden, March is an active month. Check out our tips and recommendations, and remember to check with your local experts for the best times to plant in your area.
Plan March can be a month with unpredictable weather — remember to record significant weather events in your garden journal. Make a list of new plants to include this year for our pollinator friends — milkweed for monarchs, dill and fennel for swallowtails, and rosemary, basil, parsley, cilantro, and dill blooms for bees.
- You can still order seeds. Particularly those of you in colder climates.
- Refine your garden design. Whether in your head or on paper, go outside and notice what your garden looks like this time of year when so many perennials have yet to leaf out. Are there bare spots, a lack of structure, or no cold-weather focal points? You can address those this year.
- Monitor plants. Watch for pesky pest and disease issues. Control weeds, particularly in areas where the weather is warming up. Refresh mulch as necessary, and add soil amendments and compost if needed.
- Do a final inspection. of your tools and supplies — next month, we’re off to the races!
- Protect your garden. If your ground is frozen, the soil soggy, or the lawn muddy, don’t work the soil. Doing so breaks down the soil structure, which in turn is bad for your plants. I know it’s tempting to get out there, but hold off until the snow melts, the ground thaws, and the mud drains or dries up.
- Work the beds. Start where you know you will be planting early with plants like asparagus crowns, strawberries, rhubarb, onions, shallots, and seed potatoes. Leave the other beds alone for now.
- Continue sowing indoor seeds. You want those little darlings ready to go when the weather warms! And as always, count back from recommended planting dates for your area, and sow your seeds accordingly.
- Clean up garden debris. Particularly from those beds that contain your early bloomers. Do it carefully, removing soggy leaves and fallen twigs so your plant babies can poke their heads out with confidence
- Cut back perennials and ornamental grasses. Of course, the timing of this depends upon where you live, but cleaning up old growth is sometimes what a plant needs to send up new growth. With ornamental grasses, I like to give them a pretty severe haircut just as I see some new growth at the base — this way, I enjoy their winter form and only have to live with the cut-back form for a bit.
- Prune with a goal in mind. Know which plants need pruning at what time — for example, if you prune an early flowering tree, shrub or vine now, you’re removing the future blooms. Wait until after they are finished blooming to prune those back.
- Inspect your houseplants. Some may be waking up from their winter’s sleep and may be in need of additional watering or fertilization. Look for any sign of pest or disease and treat promptly.
Zone 3: I know you’re still in a deep freeze in Zone 3, but take heart, friends, there are still things to do. If you have flowering shrubs, go ahead and prune them unless they are spring-flowering. Water any shrubs you have near the foundation of your house if the soil there is dry. Bring out your stored bulbs (tuberous begonias, calla lilies, dahlias, cannas) and place them near a light source. Start seeds of cabbage, cauliflower, marigolds, onions, tomatoes, Brussels sprouts, and asters indoors under grow lights.
Zone 4: Indoors under grow lights, start seeds of peppers, tomatoes, broccoli, brussels sprouts, cabbage, cauliflower, okra, onions, eggplants, zinnias, salvias, and petunias. If you started any seedlings last month, go ahead and pot them up. Make sure mulch is still protecting your perennials, as the sun can heat up the soil, causing new growth that is susceptible to a late freeze. Prune black knots off cherry trees, and branches killed by fire blight on apple trees and mountain ash trees.
Zone 5: Warm season crops like tomatoes, peppers, and eggplant can be started by seed indoors under grow lights. Perennials like columbine, bellflower, globeflower, and blanket flower are also good candidates for seed-starting indoors this month, as are annuals like marigolds and zinnias. Prune dead or damaged branches off of trees, shrubs, and roses, and cut back ornamental grasses to a few inches above the ground. Begin to plant potatoes, carrots, peas, lettuce, and radish directly out into the garden.
Zone 6: This is a perfect month to plant roses, trees, and shrubs if you’re enjoying mild weather. Plant arugula, kale, strawberries, peas, potatoes, sweet peas, poppies, and rocket larkspur directly in the garden, and start seeds of tomatoes, peppers, eggplants, basil, annuals, and perennials indoors under grow lights. Dig up hosta clumps that could use some dividing, then split them into smaller clumps and plant. Remember to water directly afterwards!
Zone 7: Set out your favorite herbs into the garden, but wait a bit longer to plant basil. Transplant collards, onions, cabbage, broccoli, shallots, asparagus crowns, and white potatoes into the garden, and sow carrots, beets, lettuces, radishes, and turnips after mid-month to be on the safe side. Heat-loving Swiss chard can also go in at the middle of the month.
Zone 8: Fertilize your lawn at the end of the month. Plant daisies, marigolds, petunias, and snapdragons for early season color. Got any cool season crops left to plant? Get them into the garden now — if you dawdle, the heat will do them in. In early March, sow final plantings of carrots, broccoli, beets, spinach, and turnips, and in mid-to-late March, add cucumbers, tomatoes, squash, corn, and peppers.
Zone 9: Take a look at your citrus trees, and carefully prune off any frost-damaged parts. Plant cabbage, broccoli, lettuce, parsley, radishes, spinach, and Asian greens. If you started seeds of peppers, tomatoes, and eggplants last month, harden them off by moving them outside. Be prepared to cover them or put them inside a cold frame, and plant them in the garden when all danger of frost has passed.
Zone 10: This is planting month for you lucky gardeners! Set out okra, collards, mustard, cucumbers, sweet potatoes, and melons, as well as caladiums, petunias, zinnias, and celosia. Start seeds of papaya, chayote, and jelly melon. Add compost to the soil around established trees and shrubs, as well as around new plants. Harvest peas, lettuce, kale, arugula, beets, chard, fennel, broccoli, and cauliflower.
Read More: March Garden Checklist