How Deep to Plant Vegetable Seeds?

Written & researched by Elena Marsh Gardening & Landscaping Editor

Updated October 2026

Plant a vegetable seed two to three times as deep as the seed is wide. In practice that means about a quarter inch for small seeds such as lettuce, tomatoes, peppers and brassicas, a half inch for medium seeds like beets, chard and cucumbers, and one to one and a half inches for large seeds like beans, peas, corn and squash. Sow shallower in cool wet spring soil and slightly deeper in hot dry conditions. Seeds sown too deep exhaust their reserves before reaching light and never appear.

How deep does each vegetable go?

Seed size is the governing variable because it determines how much stored energy the seedling has to push a shoot to the surface. The depths below are standard for spring sowing into a reasonable seedbed.

Where a range is given, use the shallow figure in heavy or cold soil and the deep figure in light, sandy or dry soil. Your state Cooperative Extension service publishes a planting guide with dates and depths adjusted for local conditions, and it is the most reliable source for a specific region.

Why does depth matter so much?

A seed contains a fixed energy reserve, and the shoot has to reach light before that reserve runs out. A tiny lettuce seed has enough for perhaps a quarter inch of travel; a bean has enough for well over an inch. Bury the lettuce seed an inch down and it germinates, grows toward the surface, and dies underground having never seen light. This is the single most common cause of a row that simply does not come up.

Depth also determines the seed's microclimate. Deeper soil is cooler and wetter — helpful in July when the surface bakes dry by noon, harmful in April when cold wet soil invites the seed to rot before it germinates. That is why extension guidance recommends adjusting by season rather than treating the packet figure as fixed. And for surface-sown crops, depth interacts with light: lettuce, celery and some herbs are light-dependent germinators and will not perform reliably if buried.

What technique gives even emergence?

1. Prepare a fine seedbed. Clods and stones make depth uneven, and uneven depth means a row that comes up over a week rather than in two days.
2. Make a measured furrow. Use the edge of a board, a hoe corner or a dibber marked in quarter inches rather than judging by eye.
3. Water the furrow before sowing in dry weather, then sow into damp soil and cover with dry soil. This puts moisture where the seed needs it without crusting the surface.
4. Cover with a light, fine material. Sifted compost or vermiculite instead of heavy clay, especially for small seeds.
5. Firm gently. Seed needs contact with moist soil, but compaction is the enemy of emergence. Press with the flat of a hand, not a foot.
6. Keep the surface consistently moist until emergence. A single dry-out at the wrong moment kills a germinating seed outright.
7. Mark the row so you do not disturb it, and note the date so you know when to expect emergence.

Watering technique matters more than most gardeners think, because a heavy hose stream washes small seeds several inches deeper than you sowed them. Use a fine rose or bottom-water trays, as covered in how often to water seed starting trays.

What if nothing comes up?

Dig up a few seeds and look before resowing. A seed that has swollen and produced a shoot heading upward but died was sown too deep. A seed that is soft, discolored and smells sour rotted in cold wet soil, so wait for warmer conditions. A seed that looks unchanged after two weeks is either old, dormant or in soil that never reached its germination temperature. Old seed loses viability at very different rates by crop, as covered in how long vegetable seeds stay viable.

Soil temperature explains more failures than depth in early spring. Corn sown into 50°F soil sits and rots; the same seed in 65°F soil is up in five days. A soil thermometer is a few dollars and removes the guesswork. For crops that resent transplanting and should always go straight into the ground, see best vegetables to direct sow and direct sow versus transplant, and for indoor sowing, how to start seeds indoors.

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