The seed is still hard and dry
The surface may have been sprinkled while the seed zone remained dry, or loose soil may have prevented good contact. Water the drill before sowing in dry conditions and firm gently.
Spinach can fail at several points: the seed may never absorb water, may rot after doing so, or may germinate and disappear before you see it. Digging up one or two seeds gives a more useful answer than immediately sowing the same packet again.
Get the quick answer ↓Quick answer
What this symptom usually means
After the expected window has passed, uncover one or two seeds carefully. A hard, dry seed suggests poor moisture contact; a swollen soft seed suggests rot or unsuitable conditions; a missing seed may have emerged or been eaten. Old seed and hot soil are also common causes.
- Your first check
- Use a label to locate the row and lift the top layer gently. Check two places rather than disturbing the entire sowing. Record whether the seed is hard, swollen, rotten, sprouted or absent.
Read the pattern
Clues that narrow the cause
The seed is soft or rotten
Cold, saturated, airless compost can rot seed. Improve drainage and wait for workable soil rather than repeatedly watering an already wet tray or row.
Fresh seed fails during hot weather
Spinach germination is best in cool conditions. High soil temperatures can suppress germination, making an autumn sowing or cooler shaded position more reliable.
Only scattered seedlings appear
Uneven depth, patchy drying, crusted soil, slugs or birds can all create gaps. Look for tiny stems, slime or disturbed soil before blaming seed quality.
An old opened packet performs poorly
Spinach seed loses vigour with age and poor storage. A simple damp-paper test indoors can compare the packet with fresh seed before another bed is committed.
What to do next
Useful action, in order
Make the smallest change that tests your diagnosis, then watch the newest growth rather than expecting old damage to disappear.
- 1
Run a small germination test
Place a counted sample on damp kitchen paper in a loosely closed container in a cool room. Compare how many produce roots; this tests the seed without occupying the bed.
- 2
Resow fresh seed at an even shallow depth
Prepare a firm, fine seedbed, follow the packet depth and keep the seed zone evenly moist rather than alternating saturation and drying.
- 3
Move out of temperature extremes
Use fleece or a cloche to help an early cold sowing, but avoid overheating. In a warm spell, wait or choose a cooler position for the next batch.
- 4
Protect the emergence stage
Check at night for slugs and use suitable netting where birds disturb rows. Remove protection or ventilate covers before they become too hot.
Questions growers ask
Short, specific answers
How long should spinach take to germinate in the UK?
Timing varies with soil temperature, moisture and seed age. Use the packet as the primary guide, then investigate rather than repeatedly watering if the expected window has passed.
Is my spinach seed too old?
It may be, especially if an opened packet was stored warm or damp. Test a counted sample on damp paper alongside fresh seed; the comparison is more reliable than the packet date alone.
Should I use a heat mat for spinach seeds?
Usually not as a default. Spinach is a cool-season crop and excessive warmth can inhibit germination. Aim for cool, steady conditions rather than treating it like a heat-loving crop.
Sources and scope
Evidence behind this guide
SowNext turns established growing guidance into a symptom-led checklist for UK pots, beds and small gardens. Weather, cultivar and protected conditions can change the diagnosis.