Growing from Seed: When & at What Spacing?


Radish seedlings emerging from soil.

Are you a new gardener who needs advice on growing from seed?

In the spring, we grow lots of different seedlings for our customers to plant in the garden. We start them in our greenhouse with organic potting mix. These plants include many different varieties of tomatoes, peppers, parsley, basil, kale, chard, ground cherry, cucamelon.

In addition to seedlings, we also sell organic seeds for our customers to plant directly in their gardens. This blog post is about growing from seed.

For other gardening tips, check out our page Grow Your Own.

Some General Rules

Plant the seeds about as deeply as the size of the seed. If you plant deeper than that, the seeds will either take longer to grow and use a lot of energy trying to push their way up, or they may not even grow at all. So, the smaller the seed, the less deep you should plant it.

Also keep the soil moist but not too wet from the time you first plant the seeds until the plants are almost full size.

Asian Greens and Mustard Greens.

First seeds to plant in the garden:

The following seeds are cool-hardy so they can be planted while there is still a chance of frost. Plant these as early as your garden can be prepared (has drained sufficiently and doesn’t have snow still on top):

Arugula:

We’ve been saving arugula seed for years and find that it adapts well to our climate. Most organic arugula seed is grown in Israel, which needless to say has a different climate than we do. When we buy arugula seed and compare it to our own saved seed, our locally adapted seed germinates faster and takes us with more vigorous growth. Arugula is a cold-tolerant green so you don’t need to wait until after frost before you plant it in the garden. In fact, it prefers cooler weather over warm weather and may not give you as many opportunities to cut it over the summer months. Sow the seed directly in the garden, starting in early spring. For regular cutting, sow seed every 2-3 weeks.

Baby Kale blend:

This mix of different kale varieties will give you a beautiful blend of different leaf shapes and colours for a salad, stir-fry, green smoothie, or even as a topping for pizza. Plant the seeds the same way you would arugula or lettuce mix and harvest when young. These varieties can also be left to get large and harvested as large kale leaves. Plant regularly (every 2-3 weeks) for a continuous supply.

Round red radish:

Sow seeds 1″ apart.

Broadleaf Cress:

This is a multi-functional plant. We plant the seed directly in the ground every 2-3 weeks. We harvest the peppery greens when they’re young to add to salads and sandwiches or make into pesto for pizza or pasta. They’re kind a cross between a green and an herb. And they’re super nutritious! Then when they start to bolt, we leave them in the garden. They attract pollinators as they flower and then they form green seed pods which we use in flower arrangements. Even by themselves in a vase, they’re a beautiful and unique way to bring the garden inside.

Spinach:

Spinach tends to taste best in cooler weather, so plant in the spring and the fall. Plants seeds 2” apart. If you want a continuous supply, plant every 2 weeks.

Cilantro:

Cilantro and coriander come from the same plant. Cilantro is the leafy part and coriander is the seed part. So once you’re done harvesting the leaves, you can leave the plants in your garden to flower (pollinators LOVE cilantro flowers) or you can cut the stems for an herbal bouquet or you can even eat the flowering tops (some people call them coriander greens as the taste changes). Then once the seeds have formed and dried down, you can harvest the seeds (coriander) for your herb cabinet. Plant seeds directly in garden regularly from spring through summer. Cilantro is cool tolerant so you don’t need to wait until after frost before sowing. Plant seeds 2-4” apart.

Dill:

Plant seeds directly in garden regularly from spring through summer. Dill is fairly cool tolerant so you don’t need to wait until after frost before sowing. Plant seeds 2-4” apart.

Fava Beans:

Unlike other beans, fava beans prefer cooler weather so you can plant the seeds in your garden as soon as possible. Plant seeds 1” deep and 4-6” apart.

Nigella flowers

Next to plant:  

These plants can handle some cool weather but you don’t want to stress them with too much. When growing from seed, plant about 2 weeks before last spring frost.

Early Wonder Tall Top Beet:

This variety is a good one for both the beet roots and the beet greens. Beet seeds can be planted directly in the garden, ideally once the soil temperature (soil, not air) has warmed up to 7 degrees Celsius. Plant seeds 2” apart (or thin to 2” apart after the seedlings sprout, if you planted the seeds more densely). Keep beets irrigated to avoid scab, which causes raised brown spots in the roots.

Nasturtium:

Both flowers and leaves are edible and have a pepper-flavour that is great for salads. Plant seeds directly in garden about 2 weeks before last frost. Plant 2 sds in a hole every 12” apart. Make sure you plant 1” deep because the seeds require darkness (under the soil) to germinate. Sometimes after watering, the water moves them upwards (floats) in the soil so push down in case you notice any.

Fennel:

Plant seeds 6” apart.

Carrots:

Plant seeds from early spring to mid-summer for a continuous supply (every 3-4 weeks). Plant seeds 1” apart. Seedlings take from 1-3 weeks to emerge so make sure you keep the soil moist for that whole time. A good trick to keep the soil moist during this time is to cover the area with some burlap (hold it down with something heavy like rocks on the edges so it doesn’t fly away) and make sure you remove it once the small seedlings have come up (though it does let some light in so you don’t need to worry if you’re a few days late removing the burlap).

Love-in-a-Mist Nigella flowers:

These are great for cutting and using in flower arrangements, both at the fresh flower stage and when they make pods later in the season. The stems with pods can also be dried for winter arrangements or wreaths. They also attract pollinators to the garden. Plant seeds 6” apart.

Cucumbers

Plant after chance of frost has passed:

These plants are all very sensitive to cold weather so wait until any chance of frost has passed before directly growing them from seed. If an unexpected cold night catches you after you’ve planted them, cover them up with a row cover or light bedsheet over night to try to keep the frost off.

Cucumbers:

Plant seeds directly in garden after chance of last frost has passed. Plant 3 seeds every 12” then thin after sprouting to 2 plants.

Patty pan Summer Squash:

Plant seeds into garden after chance of frost has passed. Young plants are sensitive to cold weather and susceptible to munching by cucumber beetles so row cover can be helpful (you can buy row cover from farm supply stores like Country Co-op or Shur-Gain or order through Vesey’s or Halifax Seed.

Delicata Squash:

Plant 1-2 seeds every 12”. If your soil is heavy or doesn’t drain well, make small hills to plant the seeds into because squash don’t like having their “feet wet” (which means the roots don’t like growing in very wet soil).

Fresh Beans:

Green, yellow, or purple fresh beans. Wait until after frost before planting.

Zinnias:

Wait until after frost to sow directly in the garden. Zinnias are very tender to frost. Plant (or thin after sprouting) 9” apart.

Sunflower:

Plant directly in the garden after chance of frost has passed. Plant seeds 4-6 “ apart.

Cosmos:

Cosmos might just be the easiest flowers to grow. And they are beautiful in the garden, in the vase, and to pollinators. You can keep harvesting stems and they will keep producing more. Plant seeds directly in garden after chance of last frost has passed. Plant seeds 6” apart.

Early Spring seedlings
photo by Jill Renton

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