Sowing the seeds: Alan Titchmarsh on windowsill gardening

If you’re visiting a gardening friend any time now and beauty why their windowsills are packed with little pots and punnets there’s an easy explanation. The spring seed sowing season is under way. Spare bedrooms, utility rooms and studies all make great temporary nurseries for plants that need an early start with some warmth.

I’ve even heard of folks who arrange an old ironing board next to a window to extend their propagation space (well gardeners are known for creative recycling). So in preference to buying all of your half-hardy bedding plants before everything of summer why not save a number of quid by growing your individual from scratch?

Things to sow now include all half-hardy container favourites akin to French marigolds, verbena and petunia, together with any taller flowers for cutting or for filling gaps in borders reminiscent of antirrhinums, nicotiana, pictured above, cosmos and zinnias. You are able to also sow foliage favourites inclusive of silvery Helichrysum petiolare and coleus, with flame-coloured foliage.

The other must-sow-nows are outdoor tomatoes. When you’re heating your own home anyway seed-raising on windowsills is terribly economical. For best results you’ll desire a steady temperature of 60-65F but when your heating goes off when you’re at work then it pays to speculate £20 or so in a small electric propagator.

All you have to for indoor use is a model (roughly the dimensions of 1 standard seed tray) with no thermostat. This maintains a temperature about 10F higher than that of the encompassing room, and holds approximately 15 to 18 small square plastic pots inside, that is plenty for many people.

Spread a skinny layer of fresh, moist silver sand within the base and fit the pots inside so that they cover the distance completely. Fill each pot almost to the rim with an incredible brand of seed compost. It’s not worth economising on compost: with seeds being so expensive it pays to provide them the very best start in order that most arise.

Sow one sort of flower seeds or tomatoes per pot, label them, then sprinkle a gentle dusting of horticultural vermiculite or sifted seed compost excessive , simply enough to barely cover the seeds but not more. In case you sow too deep they won’t arise. Next stand the pots in an inch of tepid water for 10 minutes until the moisture soaks to the skin.

When this changes colour you’ll know they’re done. Place them within the propagator or on a drip-tray on a bright windowsill over a radiator and wait. Depending what kind they’re seeds may germinate in days or even weeks.

When the seedlings are sufficiently big to address, usually more than one weeks when they germinate, prick them out into trays or small individual pots. They’re on the right stage when the primary pair of seed-leaves has opened out and the primary or second true leaf has sprouted in between them.

By sowing now you’ll have half-hardy flowers and young tomatoes at just the perfect stage to plant out in mid-to-late May. It’s also the time your central heating goes off so you’ve made good use of “free heat” for your windowsills.