admin
Planting seeds at the right depth makes all the difference between strong germination and seeds that dry out or exhaust themselves before reaching light. The rule of thumb is simple — plant 2 to 3 times the thickness of the seed. 
Barely covered (1/4 inch)
Basil — tiny seeds that need light to germinate. Press into the surface and do not bury.
Lettuce — light-dependent germination. Sprinkle and tamp down gently.
Celery — slow to sprout, 15 to 20 days. Keep the surface moist under a humidity dome.
1/2 inch deep
Carrot — mix fine seeds with sand for even spacing. Sprouts in 10 to 15 days.
Parsley — very slow at 3 to 4 weeks. Be patient before you assume they failed.
Radish — the fastest crop in the garden. Up in 4 to 5 days, ready to pull in 25 days.
3/4 inch deep
Tomato — start indoors 6 to 8 weeks before last frost. Needs 68 degrees or warmer to germinate in 7 to 10 days.
Pepper — needs consistent warmth. Sprouts in 10 to 15 days, never let soil drop below 65 degrees.
Eggplant — the slowest of the nightshade family. 12 to 18 days to germinate, happiest around 77 degrees.
1 inch deep
Spinach — direct sow as early as 6 weeks before last frost. Up in 7 to 12 days even in cool soil.
Beet — each seed cluster contains 3 to 4 seeds, so thin after sprouting.
Swiss chard — same seed cluster as beets. Expect multiple sprouts from one spot and thin to the strongest.
1 1/2 to 2 inches deep
Bush bean — direct sow after last frost. Dramatic emergence in 5 to 8 days.
Pea — direct sow in early spring. Seeds swell in cool soil and push up in 8 to 12 days.
Fava bean — one of the biggest seeds in the garden. Sow in late winter or early spring for a strong 10-day emergence.
3 to 4 inches deep
Seed potato — set sprouted pieces in a trench cut-side down. Sprouts emerge in 15 to 20 days, then hill up soil as they grow.
Winter squash — plant flat seed on edge to prevent rot. Up in 6 to 10 days when soil is at least 60 degrees.
Zucchini — start in pots in April or sow direct after last frost. Explosive germination in 5 to 7 days in warm soil.
