What to Plant in March: Tomatoes, Parsnips, Collards & More

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Seeding in March

Learn what to sow in March—from blight-resistant tomatoes to parsnips, greens, potatoes, and pest-fighting companion flowers—and get expert planting tips.

Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener
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At last, March is here—the first taste of spring! It’s time to sow your first crops of the season, from juicy tomatoes to frost-tolerant greens, and even a flower or two that secretly protects your garden from pests. Get your hands dirty, your seeds in the soil, and watch optimism bloom along with your seedlings.

March Gardening: What to Sow and Plant

Crop / PlantTypeSow MethodIndoor/OutdoorFrost ToleranceNotes / Companion Plants
TomatoesVegetableSeedsIndoors (2–6 weeks before last frost)SensitiveChoose blight-resistant varieties: Burlesque, Cocktail Crush, Consuelo F1, Crimson Cherry, Crimson Crush, Lizzano, Losetto, Mountain Magic. Transplant outdoors after frost.
ParsnipsRoot VegetableSeedsOutdoorsHardySow early spring in prepared, compost-rich soil. Space 1 inch apart; thin to 6 inches once seedlings appear. Intercrop with radishes for faster harvest.
RadishesRoot VegetableSeedsOutdoorsHardySow between rows of parsnips; harvest quickly before parsnips mature.
Collard GreensLeafy GreenSeeds or SeedlingsIndoors / OutdoorsHardySow indoors first, transplant seedlings to garden. Cut-and-come-again style for ongoing harvest.
PotatoesRoot VegetableSeed PotatoesOutdoorsHardyPlant main-crop varieties like ‘Sarpo Mira’ for blight resistance. Protect from late frosts with cloches or mulch.
Poached Egg Plant (Limnanthes douglasii)FlowerSeedsOutdoorsHardyCompanion flower for pest control. Scatter seeds in garden borders or under taller crops like broccoli or beans.
Peppers, Cucumbers, EggplantsVegetableSeedsIndoorsSensitiveStart indoors on heat mat to speed germination. Transplant after frost danger passes.

Starting Tomato Seeds

While you can buy small start plants at the nursery, tomatoes can also be grown from seed. Sweet and juicy, there’s no beating garden tomatoes for flavor, made all the more intense if you grow them yourself.

Consider planting a variety, from sweet cherry tomatoes for salads, perhaps plum tomatoes for sauce, and your classic tomato for slicing. 

Look for blight-resistant tomatoes! While no tomato is 100% resistant, we’ve had experience with some suitable varieties:

  • Burlesque
  • Cocktail Crush
  • Consuelo F1
  • Crimson Cherry
  • Crimson Crush
  • Lizzano
  • Losetto
  • Mountain Magic

Sowing tomatoes is straightforward. Use an all-purpose potting mix in planting pots and space the seeds as far away from the surface as possible. Then, cover lightly with the mix. Water in and cover with plastic. To speed germination (1 to 2 weeks), you can place the pots on a sunny, warm windowsill or your kitchen on a heat mat.

On the heat mat, we also grow peppers, cucumbers, and eggplants. Get yours started if you haven’t already. Once seedlings appear, you will transfer them into bigger pots or outside, depending on where you live and frost dates. See the full guide to planting tomatoes.

Sowing Parsnips for Winter Harvest

You may find it odd to think of winter when we’re just leaving it, but parsnips and leeks are planted in early spring for the winter harvest.

Parsnips, the royalty of root vegetables, are very reliable germinators, so long as the soil is warm enough. Rake the soil level and add a topping of garden compost. Mark out a couple of rows about a foot or 30cm apart. Then sow a seed about every inch or so and cover them back over. See the parsnip planting guide.

Growing Radishes with Parsnips

Because parsnips take several weeks to sprout, add a row of radishes between them; the radishes will be harvested long before parsnips need the extra space. Space the seeds about an inch apart again and cover back over. Give everything a thorough water.

The radishes should be up within a week and shouldn’t need thinning. See radish growing guide.

Once the parsnip seedlings appear, thin those in stages until the plants that are left are around 6 inches or 15 cm apart.

Sowing Leafy Greens in Early Spring

March is time for the first leafy green sowing of the year: collard greens, which are a non-hearting type of cabbage. Collards can also be harvested in more of a cut-and-come-again style, so twist off leaves as needed, leaving the plant to grow on. 

You may sow them initially into a pot, then once they have popped up, carefully transfer them into their own plugs to grow on before going out into a dedicated bed of soil enriched with garden compost.

Planting Potatoes in March

March is a great month for planting potatoes if you can offer them protection from late frosts. See our planting guide to learn how to plant potatoes in containers

For main-crop potatoes, look for a blight-resistant variety such as ‘Sarpo Mira’. Potatoes and tomatoes are related (nightshades), so they can both suffer from late blight. If you haven’t bought any seed potatoes yet, get on and do so pronto before stocks run low. 

Poached Egg Plants: A Companion Flower for Your Veg Garden

No, this is not the vegetable eggplant. Poached egg plants are flowers that are great companions in the vegetable garden. They attract beneficial bugs that will pollinate your crops and devour your pests. Lovely stuff! They’re great as a living mulch beneath taller plants like broccoli and beans, and they often stay green and protect the soil right through winter in milder areas. 

To sow along the border, the first job is to scrape back this mulch and then fork over the soil to fluff it up a bit, ready to receive the seeds. Then take a pinch of seeds, scatter them, and then tickle and pat them in. Learn more about companion flowers.

Planning Your Spring Garden

Sowing directly like this in the spring sunshine can’t help but instill a real sense of optimism. Remember: Forward planning is a must. Knowing what to sow when can be a bit of a logistical conundrum, but we find the Garden Planner is invaluable for this because it works out exactly what needs sowing when, based on data from your local weather station. Try the Garden Planner—for free— for yourself.

About The Author
Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann is the Executive Digital Editor of Almanac.com, the website companion of The Old Farmer's Almanac. She covers gardening, plants, pest control, soil composition, seasonal and moon c...