January and February are when the long-season crops should be going in — and they're exactly the weeks our windowsills can't deliver. Seeds want gentle, steady warmth from below to germinate; seedlings then want bright light from above or they stretch into pale, leggy things reaching for a sun that isn't there. A heated propagator solves the first problem, a grow light the second. Together they're the difference between a sturdy plant by April and a disappointment.
You don't need a fancy setup. A simple heated mat or a windowsill propagator gets most things going; add a small LED grow light once they're up and you've fixed the leggy-seedling problem that defeats so many people in spring.
What to look for
Propagators: the cheapest are unheated 'windowsill' trays with a clear lid — fine for spring sowings in a warm room. Heated versions add gentle bottom warmth; the best have a thermostat so you can hold a steady temperature (around 18–21°C suits most seeds) rather than cooking them. Match the size to your windowsill. Grow lights: look for 'full spectrum' LEDs — efficient, cool-running and cheap to leave on. A clip-on or adjustable-height light is ideal, kept just a few inches above the seedlings and run about 12–16 hours a day (a plug timer makes that effortless). Ignore the wild lumen claims and judge by the size of area it's meant to cover.
The options worth considering
Put the grow light on a cheap plug timer (12–16 hours) so you can't forget it, and keep it close — a couple of inches above the leaves, raised as they grow. Bottom warmth gets seeds up; bright light close overhead keeps them stocky. That's the whole secret.
Once they're up and growing, there's a full seed-starting guide and a kit list below — and a cold frame is the natural next step for hardening them off before they go out.
Get personalised dates for your postcode
Every veg patch is different. Enter your postcode and we'll work out your frost date and tell you exactly what to sow right now.
Enter your postcode