How to Sow Vegetable Seeds
Learn the different methods for sowing vegetable seeds to attain even and rapid germination.
By David Squire
Propagation (Fox Chapel, 2016), by David Squire, is the essential guide to raising new plants for the home and garden for both novice and experienced gardeners. Squire contributes his lifetime experience with cultivated and native plants with an interest in historical medicinal roles, folklore, and customs of plants. This excerpt is from “Seeds”section.
Many vegetable seeds are best sown in V-shaped furrows about 1⁄2 in (12 mm) deep for most seeds, although larger ones, such as those of French beans, need furrows that are about 2 in (5 cm) deep (see below for desired depths for specific vegetables). Seedlings in a V-shaped furrow, which produces a narrow row, will usually require thinning (see below). A few vegetables, such as garden peas, can be sown in flat-bottomed trenches; this enables a broad row to be created.
Success with Vegetable Seeds
There are five main clues to success with vegetable seeds:• Form furrows that are uniformly deep and at the correct depth for the vegetable being sown. If too deep, the seeds will not germinate; if too shallow, the seedlings will not be properly established.
• Sow seeds evenly and thinly. There is no advantage in sowing seeds thickly (often just to use up a packet).
• Cover seeds to a uniform depth.
• Thin seedlings to ensure the remaining ones are healthy.
• After sowing, keep the soil moist but not waterlogged.
Sowing Seeds in V-shaped Furrows
In winter, dig the soil. In spring, evenly firm the soil by systematically treading over it and rake it level.
Stretch a garden line between two short canes and use a draw hoe to form an evenly deep furrow (see below for depths).
Remove the garden line and sow seeds evenly and thinly in the furrow’s base (see opposite for sowing preferences).
To cover the furrow, straddle the row and slowly shuffle forward so that friable soil is pushed over the seeds. Then firm the soil by carefully walking over it. Label the ends of the rows, and shallowly draw a metal rake over the row (in the direction of the rows and not across them) to remove footprints and level the soil’s surface.
Alternative Ways to Cover and Firm Seeds
Use the flat top of a metal rake to draw and push soil over the seeds.
Firm the surface with the flat top of a metal rake; then lightly draw the rake over the row (in the direction of the row) to ensure it is level.
Vegetables to Sow in This Way
• Broad (fava) beans: furrows 3 in (7.5 cm) deep; sow seeds 9 in (23 cm) apart.
• French beans: furrows 2 in (5 cm) deep; sow seeds 3–4 in (7.5–10 cm) apart.
• Runner beans: furrows 2 in (5 cm) deep; sow seeds 6 in (15 cm) apart.
• Beetroot: furrows 1 in (2.5 cm) deep; sow seeds in clusters of three, 4–6 in (10–15 cm) apart. Later, thin to one strong seedling at each position.
• Brussels sprouts and cabbages: furrows 1/2-3/4 in (12–18 mm) deep in a seed bed, for later planting in growing positions.
• Carrots: furrows 1/2-3/4 in (12–18 mm) deep; sow thinly and later thin.
• Lettuce: furrows 1/2 in (12 mm) deep; sow thinly and later thin the seedlings.
• Parsnips: furrows 1/2-3/4 in (12–18 mm) deep; sow clusters of three seeds about 6 in (15 cm) apart and later thin to one strong seedling at each position.
• Radishes: furrows 1/2 in (12 mm) deep; thin seedlings to about 1 in (2.5 cm) apart.
• Spinach: furrows 1/2-3/4 in (12–18 mm) deep; later, thin seedlings.
• Spring onions (scallions): furrows 1/2 in (12 mm) deep; thinning is not necessary.
• Turnips: furrows 1/2-3/4 in (12–18 mm) deep; thin seedlings.
Sowing Seeds in Flat-Bottom Trenches
Garden peas are ideal for sowing in trenches, although sometimes they are sown in two furrows, 3 in (7.5 cm) deep and 8 in (20 cm) apart. However, it is easier to use a flat-bottomed trench, 2-3/4 in (6.5 cm) deep and 8 in (20 cm) wide.
On the base of the trench, position three rows of peas, 3 in (7.5 cm) apart, across the trench’s width and 2 in (5 cm) apart in the rows. Stagger the positions of seeds within the rows so that each seedling has the maximum amount of space. There is no need to thin the seedlings.
Planting Potato Tubers (seed potatoes)
Potatoes are raised from tubers saved from the previous year’s crop and known as “seed” potatoes. They are planted during mid- and late spring. Use a spade to form 6 in (15 cm) furrows that are uniformly deep.
Place seed potatoes in the base of the furrow, 12 in (30 cm) apart for early crops and 16 in (40 cm) for main crops. Position the tubers with their “eyes” (buds) facing upwards. Take care not to damage either the eyes or any small shoots.
Use a draw hoe to pull friable soil (from both sides of the row) over the tubers so that it forms a long, continuous mound 4–6 in (10–15 cm) high over the tubers. As the shoots grow, further “earthing up” of the rows will be required.
When sowing seeds in V-shaped furrows, there are three main options, depending on the seed and its size:• Continuous line: Usual way to sow small seeds, such as those of carrots, lettuces, onions, radishes, spinach and turnips. For information about thinning the seedlings, see opposite page.
• Singly spaced: Space individual seeds at intervals along the furrow. Used for broad (fava) beans, French beans and runner beans. Garden peas are also treated this way when grown in V-shaped furrows.
• In clusters: Sow seeds in clusters (usually formed of three seeds) along the furrow. Later, thin the seedlings to just one in each position.
Seeds are mixed with a gel, often wallpaper paste, and squeezed out of a small hole made in the corner of a plastic bag into the base of a V-shaped furrow. The gel helps to retain moisture around the seeds and encourages even and rapid germination.
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Reprinted with permission from Propagation, by David Squire and published by Fox Chapel, 2016.