In September, it is not only we gardeners who are making plans for next year – our plants are too. Nasturtium flowers are beginning to curl up, replaced by little seed pods that fire themselves into the soil below to grow again next spring. Broccoli plants left a bit too long are going to seed, a cloud of tiny yellow flowers that are giving the bees something to go on as the weather turns, but also offering us the chance to collect seeds to start a new generation.

This natural part of the life cycle seems particularly urgent for annual flowers and veg, which grow, flower, set seed and die in one season. Plants want to live on in their offspring, and right now they are giving birth all over the shop.

Take advantage of this by collecting these seeds, drying them out and storing for sowing next spring. Flowers like nasturtiums and mallow are great at scattering their seed everywhere – if you can’t catch them on the plant before they drop, then look out for the seedlings in spring and replant them where you want. But you could also collect seed from vegetables to sow in the new year – this is particularly satisfying when they’re relatively expensive to buy as seeds, like chillies and tomatoes.

The key rule is to only collect seed from varieties that are not F1 hybrids, because F1 means they have been cultivated to be true for one generation only – grow their seed and they will not be the same variety and could taste bitter. Non-F1 varieties are great to collect, particularly when they are rare heritage types.

If you want to collect seeds from pumpkins or courgettes, once you’ve used the veg for cooking, be aware that if you’ve grown different varieties in the same spot it’s very likely they will have cross-pollinated with each other – perhaps a long yellow courgette and a green globe would create a yellow ball-shaped variety – but their offspring may not taste as good.

Once you’ve collected the seeds, wash them clean and dry on kitchen roll indoors. Be rigorous about labelling. Once they are completely dry, store them in an old seed packet or brown paper bag, with a label, until sowing time in spring.

Strawberries are not annuals but at the moment they are sending out runners – tiny new plants carried on wiry stalks – to create new life. Strawberry runners are flinging themselves onto my paths, into nextdoor beds, anywhere where their little roots can gain a foothold.

To save them for fruiting next summer, snip the runner between the new baby plant and its parent, as though cutting an umbilical cord, and replant the child in a new pot, giving it plenty of water to see it on its way.

I collected about 30 new strawberry plants this way – including a couple which had small strawberries attached – and they are now in large pots, with several plants in each, on my paths.

Next spring I will give them their own individual small pots and donate some to our allotment plant sale and keep some to grow in a new bed.

 

Strawberry beds should be renewed every four years or so anyway, so potting on new plants from runners is a great way to keep your stock going.

Back in April I sowed some seeds of Armeria maritima, or sea thrift, in modules, which will eventually go in my rockery. These are lovely grassy plants with typically pink pom pom flowers, and love dry, alpine conditions. I put the seedlings to one side while the rest of the plot took up my time, and only remembered about them last week. They were still in their modules, like clumps of weedy grass, and would have been composted if I hadn’t spotted the label.

A tiny clump was actually nine separate seedlings, which I divided into their own pots. They won’t grow much over winter but will start to bulk up once it gets warm again in March. I will plant them out in April, once they’re a bit bigger, into the rockery.

Back in spring I had also sown seeds of Nerine ‘Bowdenii’, a pink lily-flowered plant which is normally grown from bulbs and flowers in late summer and autumn. If you start them off from seed they can take a couple of years to flower, but obviously this is a cheaper way to raise them.

 

These tiny bulblets had, by last week, little strappy shoots and so were ready to go into their own small pots. When seedlings are this small, particularly as the temperatures start to drop, be careful not to over-water as they will die from cold and wet. I’ve put them with the Armeria seedlings on the table under the parasol, where I can control the watering, but a cold frame would also do.

You can also propagate woody herbs like rosemary, mint and sage at this time of year. I have far too much rosemary that is getting very woody and lanky, so it might soon be time to raise new, fresh plants.

Select some rosemary from the top of the plant that is semi-ripe – halfway between soft green shoots and harder year-old wood – and cut a section. Remove leaves from the lower part of the stem, leaving some at the top, so that the new plant concentrates on growing roots. You can buy hormone rooting powder or gel to dip the cutting into which helps roots to grow.

 

 

 

Then place each cutting at the edge of a pot of compost – planting at the edge gives them better drainage, where they won’t get over-wet from watering. Keep undercover, protecting from wintry rain, and they should be ready to pot on or plant out in April.

You can also take cuttings of sage around now. I did this last week, although I have so much sage on my plot that I’m sure these new plants will be donated to the fete.