Planting Basics

Vegetable Seed Planting Basics: Depth, Spacing, and Germination

Getting seeds started is mostly about three things: planting depth, spacing, and consistent moisture. Use these guidelines as a reliable starting point for most common garden vegetables. (Exact needs can vary by variety and local conditions.)

1) Planting Depth (Most Common Rule)

A simple rule that works surprisingly well:

Plant seeds about 2–3x as deep as the seed is thick.

If you don’t want to think about it, use this cheat sheet:

  • Tiny seeds (lettuce, spinach, carrots): 1/8" to 1/4"

  • Small seeds (radish, beets, herbs): 1/4" to 1/2"

  • Medium seeds (cucumber, squash, melons): 1/2" to 1"

  • Large seeds (beans, corn, pumpkins): 1" to 2"

Most common mistake: planting too deep. If a seed struggles, go shallower, not deeper.

2) Plant Spacing (How Far Apart Plants Should Be)

Spacing depends on the plant’s adult size and airflow needs:

  • Leafy greens (lettuce, spinach): 6–12" apart

  • Root crops (radish, carrots, beets): 1–4" apart

  • Bushy fruiting plants (peppers, eggplant): 12–18" apart

  • Vining crops (cucumbers, squash, melons): 12–36"+ (more if they sprawl)

If you’re planting in a raised bed, spacing matters even more because plants fill space fast.

3) Row Spacing (If You’re Planting in Rows)

Row spacing is about giving yourself room to reach, weed, and harvest:

  • Greens & roots: 12–18" between rows

  • Peppers, tomatoes, bush plants: 18–24" between rows

  • Vining crops: 36–60" between rows (or use a trellis to save space)

Raised bed gardeners often skip “rows” and just space plants in a grid.

4) Thinning (The Secret to Better Results)

Many veggies are sown a little heavy on purpose, then thinned.

  • When seedlings are 2–3 inches tall, thin to the final spacing.

  • Don’t pull if you can avoid it. Snip extras at soil level with scissors to prevent disturbing roots.

5) Germination Time (What’s Normal?)

Most common vegetables sprout within:

  • Fast (3–7 days): radish, cucumber, many greens (in good temps)

  • Medium (7–14 days): lettuce, spinach, beans

  • Slow (10–21+ days): carrots, parsley, some herbs

If nothing is happening:

  • Soil may be too cold

  • You may be watering inconsistently

  • Seeds may be planted too deep

6) Watering for Seeds (Simple and Effective)

Seeds need even moisture, not a flood.

  • Keep the top layer of soil consistently damp until sprouting.

  • Once sprouted, water less often but deeper so roots grow downward.

A light mist or gentle watering is best early on so you don’t wash seeds away.