First published by Rattan Direct on 10 August 2016.

Self-seeding plants are starting to fill my garden with lots of new ones. And I haven’t paid a penny for them.

At this time of year self-seeding (a.k.a. self-setting) plants start to make themselves known. These are plants whose seeds have found an ideal niche in which to germinate and grow.

New strawberry plantlets are also appearing on runners from the parent plant.

What shall I do with all these free self-seeding plants?

In my book, there are three options. A traffic-light system, if you like.

The GREEN option

The plants have chosen a great spot and you just love them where they are. Let them be, and they’ll produce new plants every year.

The AMBER option

You’re being given a free plant opportunity!

Free plants are to gardeners as nectar is to bees: irresistible. They’re great to fill up empty spaces in your own garden, exchange with friends and neighbours, and sell for charity or your own funds at a local stall or market.

For best results, give these new plants a little care and attention. Transplant them with a trowel when young, keeping a clump of moist soil around their roots so you don’t disturb them. Replant at the same depth in prepared soil (elsewhere in the garden or in a 7-8cm / 3in pot) and water well. Keep out of strong sunshine.

When the roots have filled the small pot, transplant the plant into the next size. Hollyhocks and other plants with a tap root will need a slim, deep pot to give it room. Then grow the plant on until it’s well established. Then it’s time to plant it out or move it on.

I intend to do this with primroses that have self-set in the wrong place and some forget-me-nots whose flowers are a good strong blue. I might also do this with Granny’s bonnet (aka columbine or aquilegia). This hardy perennial flowers in May, and bees like them very much. Columbines tolerate poor soil but will only really thrive if they have deep soil for their tap root to explore. They cross very readily and so self-set seedlings often flower a different colour from the original.

I’ve also been pegging down strawberry plantlets on runners from the parent plant. When I’m absolutely certain they’ve rooted and can live alone, I’ll cut the connection to the parent plant and move them to their new bed.

The RED option

You’ve gone off these plants, had quite enough of them, never liked them, don’t like them, or just don’t want them – pure and simple. They are, as we said about weeds earlier in the year, plants out of place.

So just weed them out. No argument.

Welsh poppies are very keen on self-seeding. Despite their early flowers and early nectar for bees and hoverflies, I’ve had quite enough of them and I’m definitely going to get rid of them. I know they’ll be back, though, because they’re growing along the path and in neighbours’ gardens. In fact, I think I might have been the person who introduced them in the first place … oh dear.