A clean, fine mix
Seed needs a sterile, light mix and a clean container. Garden soil brings disease, weed seed and a crust seedlings cannot break.
Growfromseeds
- Sow in the right mix.
- Light and warmth, sorted.
- Harden off, plant out.
Plain, sourced technique for beginners, with a planner that works from your last frost date.
Sow, don't guess.
Every packet has a back with instructions. This is the longer version: the reasons behind them, so you can fix a tray when it goes wrong.
18°C
Around the temperature most seeds need to germinate. RHS, temperature
6 to 8 weeks
From sowing to transplanting a tomato. Clemson Extension, tomatoes
2 to 3 weeks
To harden off indoor seedlings before planting out. RHS, hardening off
Four things decide germination.
Light, warmth and water
Warm to germinate, bright to stay sturdy, damp but never soaked. Most failures are one of these three.
Hardening off and planting out
Soft indoor growth needs two to three weeks to meet wind, sun and cold. Tender crops wait for the last frost.
Saving your own seed
Beans, peas, tomatoes and lettuce mostly pollinate themselves, so their seed comes true. Dry it well and store it cool and dark.
Your dates, worked out.
Enter your average last frost date and see tomatoes worked out. The full planner does peppers, squash, brassicas, lettuce and more, and exports to your calendar.
Tomato, from your last frost
- Sow indoors
- enter a date
- Harden off
- enter a date
- Plant out
- enter a date
Seed to transplant: 6 to 8 weeksMore crops
Tender crops go out on or after the last frost. Source: Clemson Extension and the RHS.
Guides
Sowing
Containers, mixes, depth and the steps in order.
- How to grow plants from seed, step by step
- Growing from seed: choose a container
- Choosing a seed-starting mix
- What supplies do I need to grow seeds?
- How to germinate different types of seeds
- How deep should seeds be planted?
- Seed-starting tips
- Sowing seeds outdoors
- Why start seeds in spring
- Preparing soil for growing vegetables
Light, heat and water
What seeds and seedlings need once they are sown.
Looking after seedlings
Feeding, moving on, mould and everyday care.
Planting out
Hardening off, transplanting and timing by crop.
Saving and troubleshooting
Collecting your own seed, and what to do when nothing comes up.
Questions beginners ask.
When should I start my seeds?
Work back from your average last frost date. Seed to transplant takes 3 to 5 weeks for squash and cucumbers, 5 to 7 for lettuce and brassicas, 6 to 8 for tomatoes and 8 to 10 for peppers (Clemson Extension). The planner does the sums. Open the planner
How warm do seeds need to be?
The RHS says most seeds need around 18°C (65°F) to germinate; extension guides give 65 to 75°F. Check the mix with a thermometer, not the room. Temperature guide
Why are my seedlings tall and floppy?
Not enough light. Clemson Extension says window light is usually not enough indoors; put a grow light 2 to 4 inches above the seedlings and raise it as they grow. Light guide
How long does hardening off take?
Two to three weeks, according to the RHS and Clemson. Out by day and in at night at first, then more exposure each week. Hardening off
Nothing has come up. Is it dead?
Probably not yet. Slow seed can take weeks, and cold is the usual culprit. Dig up a seed: firm and pale is alive. Troubleshooter
Can I save seed from my plants?
Yes. Start with beans, peas, tomatoes and lettuce, which mostly pollinate themselves, and avoid F1 hybrids (University of Maryland and Montana State extension). Saving seed
Technique here, plants there. Once you know how to sow, choose what to grow.
Find your seed
Plant-by-plant seed information and organic seed sources are on organicseedfinder.com.
Go to organicseedfinder.com