Seeds Not Germinating? The Five Usual Reasons
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Too cold, too early
Germination is slow and poor in cold soil, and seed can rot if it is wet as well. Most seed germinates best at about 65–75°F (18–24°C); cool-season crops such as spinach and cabbage are happy cooler. Waiting a fortnight for the soil to warm often gives better results than sowing early.
Too deep, or not deep enough
Sow at about twice the seed’s own depth; too deep and some seed rots. Some seed, lettuce included, needs light to germinate and should barely be covered.
Dry spells and crusts
Keep the soil evenly moist; seed that dries out during germination gives patchy rows. Fine seed like carrots struggles most when the surface dries into a crust.
Old seed
Seed loses viability with age, faster for some crops (parsnip and parsley) than others. Test old packets: roll ten seeds in a damp paper towel, keep it warm, and count how many sprout.
A head start indoors
For warmth-loving crops, a heated propagator or heat mat brings soil to the right temperature. Once seedlings appear, give them light and air, and watch for damping off.
Related problems: damping off, slugs eating seedlings, why plants are not growing. Or go back to all garden problems.
Germination questions
Why did half my row come up?
Uneven moisture or depth is the usual reason. Slugs can also eat seedlings as they emerge.
How long should I wait?
Seed packets give an average range of days; cold soil stretches it.
Regional notes
The problem is the same on both sides of the Atlantic; local advice and timing differ. Trusted local guides for this page:
- UK: RHS: Slugs and snails. Timing in your area: the UK vegetable planting calendar.
- USA: Utah State University Extension: Starting vegetable seeds indoors: germination; University of New Hampshire Extension: Starting plants from seed (fact sheet); Utah State University Extension: Controlling slugs and snails. Timing in your area: the USA vegetable planting calendar.
- Canada: University of Saskatchewan, Gardening at USask: Poor vegetable seed germination. Timing in your area: the Canada vegetable planting calendar.
More problems: all garden problems.
Sources and further reading
- University of Saskatchewan, Gardening at USask: Poor vegetable seed germination
- Utah State University Extension: Starting vegetable seeds indoors: germination
- University of New Hampshire Extension: Starting plants from seed (fact sheet)
- RHS: Slugs and snails
- Utah State University Extension: Controlling slugs and snails
Facts on this page are summarised in our own words from the pages above; each is supported by at least two of them, or by one plus well-established growing science (noted in our research file). Every source was opened and checked on 23 October 2026.
Keep a garden record
Most problems come back to the same beds in the same weeks. A simple record of what grew where, and when trouble started, lets you get ahead of it next year. Sketch your beds in the free Vegetable Garden Layout Planner Tool, and keep sowing dates, problems and harvests in the Global Vegetable Garden Planner (printable PDF). Every crop we cover is in the vegetable growing guides.
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Fix The Cause, Then Plan The Next Crop
Troubleshooting works best when you improve the growing conditions and record what changed for the next season.
Keep going
Plan the next step
Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.