September Gardening Advice
September 1st, 2021 | News | Comments Off on September Gardening Advice
With the sun setting a little earlier each day, September is the crossroads month. We may still enjoy those warm days and orange glow sunsets, but the nights are drawing in and the temperatures are dropping. It’s a month of change.
However, the good news is that veg plots are brimming with crops that need to be eaten or stored. From potatoes to onions to runner beans, your hard work has come to fruition. Squashes and pumpkins have taken on their plump autumnal glow, and autumn raspberries tantalise you with their juicy ripeness.
As the saying goes, ‘make hay while the sun shines’, which means we need to get out there and harvest. In a few weeks, the warmer weather will be no more than a distant memory, and autumn will be snapping at our heels. So, let’s enjoy the last of the sunshine and savour the rich reds and burnt oranges of tithonias, dahlias and zinnias.
In the flower garden
Greenhouse
With your tomatoes, cucumbers, chillies, peppers, aubergines, and melon now spent, it’s time to clean your greenhouse, polytunnel or cold frame. Burn or dispose of old plants and remove all empty pots and containers, as these maybe harbouring pests.
Ensure all glass is cleaned; warm soapy water should do the trick. Don’t forget to clean the greenhouse floor too, as potential pests and diseases could still be lurking. Pack away any shading you put up during the summer months.
If you’re planning to grow anything in the next few months, then your greenhouse will need as much light and warmth as possible. Carry out any maintenance needed, clean leaves from guttering (including downpipes and water butts), and test any greenhouse heaters.
Lawn
By now, lawns could be looking a little worse for wear, and will need a little attention so they can go into winter untroubled. Re-lay any bare patches with new turf, or re-sow seeds directly into the soil. Scarify, aerate and apply a dressing to the lawn. Keep edging in check and remove any fallen foliage, as this can encourage thatching. The change of season will mean the grass will slow its growth and you’ll be mowing less frequently.
Flower beds
Although we’re enjoying the last moments of summer’s touch, it’s time to look ahead to next spring. As you clear away the last of the summer bedding, give your borders a refresh. If you’re not planting autumn flowers, such as chrysanthemums, clear weeds, add compost or mulch and think about what to plant for the following spring. Biennial varieties such as wall flowers, foxgloves, as well as polyanthus, pansies and sweet Williams, can now be planted. This will give the plants enough time to get their roots established before the colder weather bites.
Perennials
With the ground still warm, new perennials should be planted before the colder weather arrives. For perennials that are still blooming, continue to deadhead and tie-in. If they’ve given their best, think about digging them up, dividing and replanting. Not only are you invigorating the clump, but you’re getting more flowers for your money. Ensure these plants are well watered in and mulched.
Another way to increase plant stock is to take cuttings. Tender perennials, such as penstemons, salvias and fuchsias are ideal for this. Once potted up, they will quickly establish a healthy root system. Place them in a sunny, protected area that’s frost free. Overwatering, or keeping them somewhere damp, may lead to dampening off, so check on your cuttings regularly.
Hanging baskets
To keep hanging baskets blooming, continue to feed, water and deadhead regularly. However, if summer baskets are spent, think about replacing them with a winter display. Consider plants such as polyanthus, crocus, cyclamen and trailing ivy. Plant up with fresh compost and water in well.
Bulbs
It might be a touch early to plant your tulip and allium bulbs for next year, but other bulbs are ready to go. Plant amaryllis and hyacinth bulbs now. Force their growth and you’ll be enjoying their colourful blooms come the festive season.
If you’re thinking a little further ahead to next spring, then daffodil and lily bulbs can also be planted. Plant them into flower beds to the depth of three times their height, or consider pots and containers if space is an issue.
Sowing
Plants such as sweet peas, centaurea and poppies can now be sown into trays or modules. Don’t let them dry out and, as temperatures slowly start to drop, ensure preparations are made to see them through the colder months.
On the veg patch
Fruit
You should now have rich pickings of apples and pears, and what can’t be eaten straightaway can be stored. Firstly, check that none are spoilt, then place them on dry sand in a paper-lined box, ensuring none are touching. Place the box somewhere dark and cool, such as a pantry or cellar, and check every so often to make sure none have gone off.
As long as you keep picking, autumn raspberries will continue to produce fruit right up until the first frost.
Whether they’re newly bought plants or runners you took from your own plants, strawberry plants need to be planted. The ground is still warm, so this will give them enough time to get established.
With the fruit all harvested, complete your summer pruning. Tie in all trees and bushes, and give them a feed or mulch.
Harvest
With the last of the tomatoes harvested, place any remaining green fruit in a paper-lined shoebox with a ripened banana and keep them somewhere warm. Check regularly and remove them once reddened. Failing that, green tomatoes make excellent chutney.
Continue to harvest vegetables such as courgettes and marrows. Any onions still in the ground should be lifted, dried and stored.
The vine on certain squashes and pumpkins may now be cracked and withered. This is a tell-tale sign that the crop is ready for harvesting. Cut the vine away, a few centimetres above the fruit, then leave them somewhere dry and bright for a few days so the skin can harden off. Finally, store somewhere cool and dark.
Sow
With an empty cold frame or greenhouse, consider sowing hardy lettuce or spinach over the colder months. Varieties to consider are lambs lettuce, miner’s lettuce and perpetual spinach. If you want to fill a few empty vegetable beds, autumn planting garlic, onion sets and shallot sets are all fit for purpose. However, if your vegetable beds are to remain empty, try sowing green manure. This will suppress weeds and help break up heavy, clay soil. Come March, cut up the foliage and dig it into the soil, as this will provide many of the soil’s required nutrients.
Pests and diseases
Pest and diseases are still very much present, including wasps. With plenty of ripening fruit, they could potentially spoil your crop, so hang wasp traps in trees and bushes.
However, as wasps are also beneficial for your garden (they eat aphids, caterpillars and other pests as well as being good pollinators), you may want to consider a more humane way to deter them. One option is to cover your crops with fine netting or mesh.
Other jobs
- Bring in any indoor plants you rested outside over the summer months.
- Reduce the frequency of watering your houseplants.
- Prune roses that are no longer flowering.
- Continue deadheading dahlias.
- Plant up herbs for the winter months ahead.
- Order allium and tulip bulbs for next spring.
Written by Ade Sellars, garden writer and presenter.