Sowing Guide
Why sow from seed
Growing from seed slows you down in the best way. It lets you choose varieties for flavour, resilience, and seasonality, and gives you control from the very beginning. Good seed, handled well, removes most problems before they appear.
Before You Start
Use good seed
Start with fresh, well-stored seed from a reliable source. Old or poorly stored seed may germinate unevenly or not at all.
Get organised
Label everything as you go. Trays, pots, rows, and dates all blur together surprisingly fast once the season gathers pace.
Where to Sow
Indoors (recommended for most crops)
Sowing into trays, pots, or modules gives you consistency and protection. It avoids losses to pests, cold snaps, and erratic spring weather, and allows you to select the strongest plants before planting out.
Best for:
- Tomatoes, peppers, aubergines
- Squash, cucumbers, melons
- Flowers with fine seed
- Any crop started early in the season
Direct sowing
Some plants dislike disturbance and are best sown where they’ll grow to maturity.
Best for:
- Carrots and parsnips
- Peas and beans
How to Sow
Compost
Use a fine, free-draining seed compost. Fill containers fully and firm gently so there are no air pockets.
Depth matters
- Very small seed: sow on the surface or barely covered
- Medium seed: cover lightly (around 5 mm)
- Large seed: sow deeper, roughly the depth of the seed itself
If in doubt, sow shallower rather than deeper.
Watering
Pre water trays and pots to ensure seedlings don't get washed away. Water gently and spearingly so seeds are not displaced. A fine rose or bottom-watering works best. Keep compost moist but never saturated.
Germination
Warmth
Seeds need warmth to wake up. Each crop has its own range, but most will germinate reliably in a consistently warm place.
- Cool-tolerant crops can germinate at low temperatures
- Heat-loving crops need sustained warmth to avoid rotting
Heat mats, warm shelves, or bright indoor windowsills all work if temperatures are steady.
Light
Most seeds don’t need light to germinate, but seedlings need it immediately once they emerge. A few crops: including celery, celeriac, parsley, and lettuce — require light to germinate and are best sown on the surface. Without enough light, seedlings stretch quickly, becoming tall, weak, and fragile. Move trays into good light as soon as shoots appear
Seedlings
Air and spacing
Crowded seedlings quickly compete for light and nutrients. Good airflow reduces disease and keeps growth sturdy.
Pricking out
When seedlings are large enough to handle, move the strongest into individual cells or pots. Handle by the leaves, not the stem, and disturb the roots as little as possible.
Potting On
Plants can remain in seed cells for a short time, but once roots fill the space, growth slows. Moving plants into larger pots keeps them growing steadily while you wait for outdoor conditions to improve.
Planting Out
Timing
Plant out when seedlings are sturdy, not rushed. Smaller plants often establish faster than oversized ones.
Hardening off
Gradually introduce plants to outdoor conditions over several days. This helps them adjust to wind, temperature changes, and full light.
Planting technique
Make a hole slightly larger than the root ball. Set plants at the same depth they grew before, firm gently, and water well.
Watering After Planting
Water deeply at planting time, then monitor closely for the first week. Newly planted seedlings need moisture to establish roots, but soggy soil will set them back.
Morning watering is best. Aim for the soil, not the leaves.
A Few Quiet Rules
- Sow more than you need; losses are part of gardening
- Don’t rush early sowings unless you can provide warmth and light
- Strong plants come from steady conditions, not constant interference
- Good spacing now saves work later
Growing from seed rewards patience. Pay attention early, and the rest of the season becomes easier.
