Self-sown plants can make our lives easier, but the key is to grow them direct in the soil with barely any intervention. No seed trays, no compost, no pots and therefore no potting on. Instead, they plant themselves, grow themselves and flower themselves with tremendous ease – not bad for sustainability credentials.
All we have to do is remove excess numbers at the seedling stage, which is when that feeling of “too much effort” might creep in. Among hundreds of tiny seedlings, how to spot which are weeds and which are desirables?
Looking at photos of seedlings online and in books is largely useless because so many look similar and you need to spot tiny differences such as the shape or shade of a tiny leaf. Best then, is to get started by getting your eye in: by seeing the plants grow from seed yourself, you’ll spot them more easily in future years. Opium poppy, for instance, has a pale green-silver colour and jagged leaves easily identified.
If you’ve never grown a particular self-sower before, the easiest way to start off is to grow some in a pot of peat-free compost or in rows in the soil. By using rows you can be sure the seeds that come up are the ones you sowed, whereas broadcasting the seed all over the place in the first year leads to the seedling in a weedstack problem.
Sowing seeds in a straight line also allows you to thin the line when plants are established, with six-to-eight leaves, and remove plants to the desired spacing listed on the seed packet. Thinning also breaks the line for a more natural look (nowadays I make the line curved or squiggly to aid this).
Many of the self-sowers on my allotment started life in straight cut-flower bed lines, breaking ranks themselves the following year. Because I’d grown them in labelled rows initially, I recognised the seedlings when they sprung up in unexpected corners.
Take tips from nature
We categorise plants using terms like annual and biennial but they sometimes have other ideas: many hardy annuals grow biennially if sown in late-summer or autumn, flowering early next year. A second spring sowing of the annuals provides another burst later in the season.
Many of these plants naturally produce seed and this indicates that it is the right time to sow their seeds from packets too. To prolong flowering, of course, you can simply delay seed production by deadheading flowers.
Easy to grow, many in number, long flowering and spreading freely, surely self-sowers are the hardest working plants in any garden, both low in cost and high in value.