As colder weather beckons, now is the time to save your plants, tackle your soil, harvest the last of your summer veg and protect crops during winter.
Don’t leave it until the ground’s too hard to work, your edibles are impossible to lift out of the soil, and the roots of your taller plants have succumbed to wind rock because you didn’t cut them back.
Emma O’Neill, head gardener of the horticultural charity Garden Organic, offers the following tips…
Mulch flower beds and borders
Home-made compost is best for mulching, O’Neill advises, although you can also obtain green waste from your local council. Mulching will not only protect the roots of your plants from freezing but it will also add structure to the soil.
Prune roses
Give your roses a trim to reduce the risk of wind rock, which causes their roots to lift and allows frost to damage them. “Take them down roughly by a third or a half, depending on how large the rose bushes are,” says O’Neill. “That way, you are reducing the volume of plant that the wind can get to.”
Protect tender plants
Leave the stems on more tender border perennials, such as penstemon and salvia, to protect them from the winter chill. Also, leave flowerheads on hydrangeas to protect the shrub over winter – and add architectural value when everything is looking pretty bleak, O’Neill advises.
You can also leave the stems and flower centres on hardy perennials such as heleniums, echinacea and rudbeckias, which will create winter habitats for wildlife.
“You will need to cover some plants with horticultural fleece if you don’t want to lift them,” O’Neill adds, mentioning dahlias and cannas, which should be left until the first frosts, when the foliage has gone black, before cutting the top growth off and then protecting them with fleece.
“If you don’t have a place to store them, use fleece to cover plants. It’s the best thing as it allows light, air and water in, whereas other coverings can cause them to rot or develop mould or fungus.”
Stop patio pots from cracking
“With container plants, make sure you’ve got the pot feet underneath, because even terracotta pots will crack in the frost if they’re not off the ground. Stop feeding pot plants, because any delicate new growth they develop will be lost in the frost, and stop watering,” says O’Neill.
Move tender plants in pots into a frost-free area – it could be a garage or a shed – or wrap the plant and the pot in horticultural fleece, so the compost in the pot doesn’t freeze, she adds. If you have potted pelargoniums or other specimens which are treated more like bedding plants, move them undercover, in a greenhouse or conservatory.
Look after winter crops
“You should still be planting out your autumn garlic and onion sets now. If you have winter salads, put cloches over them to protect them from the worst of the weather, unless you’re growing them undercover.”
Even if you have a glass house or a polytunnel, temperatures can plummet to minus-five-degrees Celsius undercover, so check that you have adequate heating, or you will still need to be putting fleece over the plants inside.
Check ponds
“It’s a good idea to have something in your pond like a football or tennis ball to stop it completely freezing over, so that the pond is still oxygenated, which is essential for wildlife such as fish, frogs and toads,” O’Neill advises.
Sow green manure
“You’ve only got a limited period now to protect your soil, so sow green manures like fenugreek, crimson clover and trefoil now, because by the end of October they are unlikely to germinate,” says O’Neill. “Sow them in your veg garden after you’ve harvested everything, so if you end up with a bare bed and it’s too late to successional-sow, at least the green manure will protect the structure and limit the amount of weeds you get.
“Certain green manures will nitrogen-fix the soil and add nutrients. If you have a no-dig system you can ‘chop and drop’, cutting off the tops (when in leaf), which will put nutrients into the soil.”
