How to sow your seeds
Growing perennials from seed is very straightforward – there’s no mystique and no expertise involved. After all, we’re just emulating nature. However, we do have the advantage of ensuring our seeds have the best possible conditions to germinate, whereas in the wild success is down to chance.
Use a proprietary seed compost, ideally with some loam content, rather than home-made garden compost. The latter is great to use as a mulch outside, but it contains fungi and other pathogens that may cause seeds or delicate seedlings to rot in the confines of a pot or tray.
Be creative with your containers – sow your seeds into recycled plastic punnets and tubs, or old pots and trays (thoroughly washed), rather than buying new.
Sow sparsely – it’s very tempting to sow lots of seeds ‘just to be on the safe side’, but try to resist. Seeds may germinate well and look
fresh and green, but as the seedlings grow they’ll form a dense jungle, giving harmful fungi the opportunity to thrive. This can result in the rapid collapse of the entire contents of the pot or tray – known as damping off. Seedlings need air and light, so space out your seeds as much as you can.
Prick out seedlings promptly, once the first true leaves form. Most seedlings produce two initial seed leaves (apart from monocots like grasses and irises, which have only one). This first pair of leaves enables the little plant to photosynthesise straight away. Shortly afterwards, the first true leaves appear.
This is the time to prick out the seedlings, moving them into more spacious accommodation, in their own module, a small pot or a bigger tray. I use a chopstick to gently lever out the roots. Always hold seedlings by the seed leaves, which are dispensable, rather than the stem, which is not.
Water well and keep in similar conditions to the first seed tray.
Plant out your young plants once their roots have filled their pot and they’ve put on lots of strong, sturdy growth. It’s best to wait until after the last frost, and for half-hardy and tender plants, this is essential.