Support winter greens
If you followed our method of planting tall brassicas deep into the ground, they will now be well anchored to stop them blowing over in the winds of the year’s end. Brussels sprouts, kale and spring-flowering broccoli are all vulnerable; if they’re planted in a block rather than in rows, they’ll help shelter and support each other. If you use a small stake or stout cane for any plants that might be suffering, be careful not to let the support rub against the plant.
Any green tomatoes left on your plants need the sun to help them ripen; you can, this late in the season, remove any leaves shading the tomatoes without harming the plant. It’s best, if possible, to let the tomatoes ripen on the stalk so that you have a steady supply; if you remove too many at one time to ripen them inside, you risk having a glut. If you do have to take them all off at the same time, you can put them on a sunny windowsill or put them together in a brown paper bag. The best method is to place them close to another ripe fruit, especially a banana, as the gases they give off will bring them to maturity.
Squashes and pumpkins
A hardened skin is important if you want to store your squashes, pumpkins and marrows for later use in the winter. The first to set will be the best to store; leave them on the vine until the plant begins to die down. (Use the less mature ones now.) Once they’re picked, leave them outside in the sun and, if possible, raise them off the ground so that the air can circulate. If I were to grow only one variety, it would be the butternut squash, one of the tastiest and an excellent keeper, although here it tends to set late in the season, which makes storage a little more difficult.
Cut down asparagus plants as soon as the foliage starts to go yellow to stop them being knocked and rocked by the wind; movement may enlarge the space around the bottom of the stems where water can collect and cause crown rot. With asparagus and other permanently planted crops, weeds can be a trial, but you can control them by regular hand-weeding. If you take off the foliage now, it will be easier to hoe out the weeds and rake them away. Compost or mulch applied afterwards will help to keep down the weeds and replace lost nutrients, too; if you do this every year, you’ll see the development of the typical ridges. Plants can last up to 12 years, so you should be ready to put in a new bed before production slows down. It’s essential to keep an eye on your early planted new crowns for damage by mice they love nibbling the tender shoots developing underground.
There’s still time to propagate Penstemons before the frosts start. Osteospermums and Erigerons will root well at this time of year; it’s a good way to make sure your stock survives and increases. Always use the best cuttings you can find, which will usually be a vigorous, non-flowering tip. Put your cutting in free-draining compost under glass and preferably on a heated bench. Any Pelagoniums you might have outside in containers are also best propagated now, before the frosts.
Philip Maddison is head gardener at Harrington Hall, Lincolnshire (www.harringtonhallgardens.co.uk)