What to Plant in March: Best Vegetables to Sow

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.

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

On the heat map, 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

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.

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. See the parsnip planting guide.

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 six inches or 15 cm apart.

Sowing Greens

March is time for the first leafy green sowing of the year: collard greens, which are just 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

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 maincrop potatoes, look for a blight-resistant variety such as ‘Sarpo Mira’. Potatoes and tomatoes are related, 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. 

Planting Poached Egg Plant Flowers

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. And then take a pinch of seeds and scatter them… and then tickle and pat them in. Learn more about companion flowers.

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.