Why vegetable seeds fail to germinate

First check: compare the time since sowing with the seed packet's expected germination period. Some crops emerge quickly; others need patience. An empty row does not yet tell you whether seeds failed to sprout or seedlings disappeared afterwards.

Check conditions at seed depth

Moisture must reach the seeds, not just wet the surface briefly. Tiny seedlings and germinating seeds are particularly vulnerable when the upper soil dries or forms a hard crust. Water gently enough to avoid washing seed away, and check beneath the surface.

Compost should be moist and free-draining. Saturated trays can leave seeds short of oxygen and encourage decay. Check drainage holes rather than compensating with more heat or feed.

Temperature requirements vary. Soil can be cold despite a warm afternoon, while a covered tray in direct sunshine can overheat. Use the crop's stated germination range and measure where the seeds sit if failures recur. More warmth is not always better: lettuce and spinach can struggle to germinate in excessive heat.

Review the seed and sowing method

Check the packet's date and how it has been stored. Age, heat and damp storage can reduce viability. Follow the crop's depth and light instructions; burying very small seed deeply can cause problems, while shallow sowings may dry rapidly.

If you suspect an older packet, test a small counted sample on moist paper in a container under the crop's recommended conditions. Keep it damp rather than waterlogged and allow the expected time. This helps distinguish weak seed from a difficult seedbed, although a home test cannot predict every outdoor result.

Look for losses after germination

Slugs, birds and other animals may remove seedlings before you notice them. Inspect after dark and look for disturbed soil or remains. Soft, decayed seedlings may indicate damping off; compare with the collapsing-seedling guide.

Decide whether to resow

If the expected window has passed, investigate a small part of the row without disturbing everything. Resow a manageable batch after correcting the likely cause and checking that enough growing season remains. Keep the replacement labelled so it does not become confused with a late first sowing.

Record sowing and emergence dates in Your Growing Companion, and use its sowing calendar as a planning aid alongside seed-packet guidance and your actual soil conditions.

Back to Solve a Growing Problem · Find your crop guide

Further reading: RHS guidance on sowing vegetable seeds and sowing during heat; University of Minnesota Extension on starting seeds and moisture during germination.

By Simon Adams · Published 27 October 2026. Adapt advice to your crop and conditions.