March is the month spring stops being a promise and starts being a schedule, and the garden tasks in March are the busiest of the early year. One week can bring warm sun and the next a hard frost, so the skill in March is doing the right job in the right zone at the right moment, and holding your nerve when the weather turns. This guide splits the work by zone band — cold zones 1–4, temperate zones 5–7, warm zones 8–10, and frost-free zones 11–13. Frost dates are given only as averages and ranges, never as exact dates for a particular place, and zones 11–13 are frost-free, so their calendar runs on heat and rain instead. Before you act on any timing here, check your local extension service for the frost dates and sowing windows that fit your area.
Cold zones 1–4: start tomatoes and wake the garden gently
In zones 1–4, average last frost dates fall roughly from late May into June, so March is still an indoor month, but it is the most important indoor month of the year. Seed starting peaks now: start tomatoes, peppers if you have not already, eggplant, broccoli, cabbage, cauliflower, lettuce, onions and celery under lights. Tomatoes sown in March will be sturdy, stocky plants by planting time, where January-sown ones would be leggy. Use our seed-starting calculator to set your dates, and give seedlings strong light close above them, plus a gentle fan for airflow, which builds sturdier stems. See the tomato growing guide for spacing and support plans you should be making now.
Direct sowing outdoors is still very limited, though in the mildest corners of zone 4 you can sow peas and broad beans under cover late in the month if the soil is workable. The squeeze test still rules: if a handful of soil stays in a wet ball, wait. Transplanting outside is not yet possible, but pot on indoor seedlings into larger pots as they grow, and start hardening off nothing yet — that comes in May. Pruning can begin in earnest once the worst cold has passed: prune fruit trees, grapevines and dormant roses on a dry day, removing dead, diseased and crossing wood and opening the centre for light. Our pruning calendar shows the order. Fertilising is still minimal, though seedlings in fresh mix need nothing yet, and you can top-dress fruit trees with compost. Pest and disease watch means checking seedlings daily for damping off and fungus gnats, and inspecting stored tubers and fruit trees for scale and canker while branches are bare. Watering outdoors is still nil while the ground is frozen or sodden, but check containers in sheltered spots on mild days. Harvesting is thin — stored crops, forced rhubarb in zone 4, and windowsill herbs — but the first overwintered leeks and parsnips can still be dug. Soil and compost work starts to open up: spread compost on beds as they thaw, turn the heap, and take a soil test now so results arrive before spring. Houseplant care shifts in March: days are longer, so increase watering, start feeding at half strength once growth is steady, and repot any plant that is root-bound before the growing season.
Temperate zones 5–7: sow, transplant and prune before bud break
Zones 5–7, with average last frost dates generally from mid-April to mid-May, turn March into the great sowing month. Seed starting indoors continues for tomatoes, peppers, eggplant, cucumbers, squash, lettuce, broccoli and herbs, and you can start sweet corn indoors in zone 7 late in the month for an early crop. Keep lights close, water from below, and thin seedlings to the strongest one per cell.
Direct sowing outdoors opens up properly: sow peas, broad beans, lettuce, spinach, kale, radishes, beets, carrots, turnips, onions and potatoes in zones 6–7, and in zone 5 sow the hardiest of these under cover. Sow peas and lettuce little and often for succession, and see the lettuce growing guide and carrot growing guide for depth and spacing. Transplanting begins: set out broccoli, cabbage, cauliflower, lettuce and onion seedlings under cloches or fleece, hardening them off for a week first by putting them outside by day and bringing them in at night. Pruning must be finished before bud break: complete fruit tree, rose and grapevine pruning early in March, and do not prune spring-flowering shrubs until after they flower. Fertilising starts: feed roses and fruit trees as buds swell, top-dress vegetable beds with compost, and feed lawns lightly if they are actively growing. Pest and disease watch means looking for slugs on young seedlings after rain, checking brassicas for cabbage worms, and clearing fallen leaves from around roses. Watering needs attention as the soil dries in spring sun: water new transplants well, water in the morning, and avoid watering frozen or sodden ground. Harvesting improves: leeks, parsnips, overwintered spinach and kale, rhubarb and the first asparagus in zone 7. Soil and compost work is central in March: dig in compost, fork over beds lightly without destroying soil structure, mulch bare soil, and sow green manures on beds that will not be used until summer. Houseplants are in full growth now: repot, resume regular feeding, and move them to brighter spots, but keep them away from cold draughts on frosty nights.
Warm zones 8–10: plant out tender crops and sow summer vegetables
In zones 8–10, average last frost dates run roughly from late January in zone 10 to mid-March in zone 8, so March is planting-out month. Seed starting indoors winds down for warm-season crops, though you can still start okra, melons, cucumbers and squash indoors for a head start, and start herbs such as basil now. Sow sweet corn direct once the soil has warmed, and see the sweet corn growing guide for spacing.
Direct sowing is broad: beans, squash, cucumbers, zucchini, corn, okra, melons, lettuce, carrots, beets and radishes all go in, and in zone 8 wait until after the average last frost for the tenderest of these. Transplanting is the headline job: plant out tomatoes, peppers, eggplant and basil after the average last frost, hardening them off first, and set out sweet potato slips in zones 9–10 late in the month. See the eggplant growing guide for what those transplants need. Pruning is finishing work: complete rose and fruit tree pruning early in March, deadhead spring flowers as they fade, and cut back frost-damaged growth once new shoots show where the live wood is. Fertilising is in full swing: feed vegetables, roses, fruit trees and citrus, and side-dress heavy feeders such as corn with compost or a balanced feed. Pest and disease watch steps up sharply: aphids on new growth, cabbage worms on brassicas, slugs after rain, and early blight on tomatoes in wet springs all need weekly checks. Watering becomes a real job as temperatures rise: water deeply and less often to encourage deep roots, mulch beds thickly, and water in the morning. Harvesting is generous: peas, lettuce, spinach, broccoli, cauliflower, carrots, beets, herbs and the last citrus, and our harvest date calculator can help time the pickings. Soil and compost work means mulching beds before summer heat, turning the heap, and adding compost to beds between crops. Houseplants can move outside for the season in zones 9–10 once frost risk has passed, and start feeding them regularly now.
Frost-free zones 11–13: heat builds and succession sowing matters
Zones 11–13 are frost-free, so March has no frost dates to wait for. The challenge is the opposite: heat is building, and leafy crops will bolt sooner, so succession sowing and shade matter more than frost protection. Seed starting is mostly direct, but keep starting tomatoes, peppers and eggplant in trays for reliable stands, and sow heat-tolerant greens such as Malabar spinach and amaranth as the weather warms.
Direct sowing covers beans, corn, squash, cucumbers, melons, okra, sweet potatoes, carrots, beets and herbs, with lettuce and spinach sown in the shadiest beds and harvested young before they bolt. Transplanting is continuous: set out tomatoes, peppers, eggplant, basil, cucumbers and tropical flowers, and plant fruit trees and shrubs now. Pruning is tidying and shaping: cut back spent growth, shape tropical shrubs, and prune citrus after harvest. Fertilising is regular and light: feed vegetables every few weeks, feed fruit trees and citrus, and refresh beds with compost between plantings. Pest and disease watch is weekly and year-round: check for aphids, whiteflies, spider mites, caterpillars and fungal spots, and remove affected leaves promptly. Watering needs to increase as heat builds: water deeply in the morning, mulch heavily, and check containers daily. Harvesting is abundant: tomatoes, peppers, cucumbers, beans, leafy greens, herbs, citrus, bananas and papaya. Soil and compost work never stops: keep the heap hot, add green waste, and top beds with compost. Houseplants outdoors need repotting and dividing in March, and indoor plants should be checked for pests that spread fast in warm rooms.
Tool maintenance and the March checklist
March is when tools earn their keep, so finish maintenance now: sharpen mower blades, clean and oil secateurs, check hoses and irrigation, and set up supports, stakes and cages before plants need them. It is far easier to put a tomato cage over a small plant than to wrestle one over a large one. Also label everything you sow, keep a sowing log, and check your local extension service for any March pest alerts in your area.
Frequently asked questions
What should I sow in March?
In zones 1–4, sow tomatoes, peppers and brassicas indoors. In zones 5–7, sow peas, lettuce, spinach, radishes and carrots outdoors, and tender crops indoors. In zones 8–10, sow beans, squash, cucumbers, corn and okra outdoors and plant out tomatoes after the average last frost. In zones 11–13, sow almost everything direct, with heat-tolerant greens as temperatures rise. Check your local extension service for the windows that fit your area.
When can I plant tomatoes outside?
Only after the average last frost and when night temperatures stay reliably above freezing, with warm soil: roughly May in zones 1–4, late April to mid-May in zones 5–7, March in zones 8–10, and year-round in frost-free zones 11–13. Harden seedlings off for a week first, and use our seed-starting calculator to set your dates.
Should I prune in March?
Finish dormant pruning early in March in zones 5–10 before buds break, and start it in zones 1–4 once hard frost has passed. Do not prune spring-flowering shrubs until after they bloom. In zones 11–13, March pruning is tidying and shaping after harvest rather than dormant pruning.
What can I harvest in March?
In zones 5–7, leeks, parsnips, overwintered greens, rhubarb and early asparagus. In zones 8–10, peas, lettuce, broccoli, carrots and the last citrus. In zones 11–13, tomatoes, peppers, beans and herbs. In zones 1–4, mainly stored crops and forced rhubarb.
How do I stop seedlings going leggy in March?
Give them strong light just a few inches above the leaves, keep them cool at night if you can, give them airflow from a gentle fan, and do not sow tender crops too early. Leggy seedlings rarely recover fully, so it is better to sow a second batch at the right time than to nurse a stretched one.