September is a changeover month in your garden, preparing for the Winter and Spring. It’s harvest time mid-month, into October, and because the daylight hours are getting shorter it’s best to make the most of good days where you can.
If you have fruit and vegetables in your garden, harvest as much as you can on dry days. Autumn raspberries should be picked: eat and enjoy them fresh, and if you have too many, freeze or make preserves. Potatoes need to be lifted from the soil and left to dry for a few hours on the soil surface. They can be stored in hessian or paper sacks. Containers that are composed of plastic will create condensation and will cause rotting.
If you’re growing pumpkins or squashes, place a piece of slate or wood underneath them to stop them rotting on the ground.
Remove any apples, pears or plums that are left on trees – if they are left to rot, they are likely to spread disease. Clear away any straw around strawberry plants as they can also encourage pests and diseases. In general, remove any finished crops, weed and tidy your vegetable plot ready for the Winter.
Now’s the time to plant Spring flowering bulbs. If you have children (or grandchildren) enlist their help as planting bulbs is easy. Come the Spring, their (your!) efforts will be rewarded with flowers. Daffodils, hyacinths, and snowdrops will bring your garden to life when the grey of Winter gives in to the emerging Spring.
Plant at least six bulbs together in the same hole to get a good display, and space them out in the hole – make the gap twice the width of the bulb – then cover with soil. Don’t tread on the soil to fill up the hole, as that may damage the bulbs. Just cover and lightly press down. You probably won’t need to water bulbs planted in September, there’s generally enough moisture in the soil.
Bulbs work really well in containers and pots. Remember to keep checking that they are getting enough moisture before Winter arrives. Lilies and alliums make lovely displays in pots, and can be planted this month.
Now is also the time to divide waterlilies, hostas, salvia, delphiniums, geraniums, agapanthus and more. Dig the plant out with as much root as possible, and then pull apart gently. Some plants require a more forceful split using a sharp knife or spade. Once they’re divided, plant as soon as possible and water well.
September is a great time to lay turf or seed a new lawn, or patch up where necessary. Adjust your mower blades to their higher level as grass is slowing down. Give your lawn a feed with a potassium rich, low nitrogen fertiliser.
Keep deadheading! Baskets and containers will keep going until the frost arrives, as will roses and other annuals in the garden.
Collect and store seeds from healthy plants. It’s a great way to keep your gardening investments going, and is really rewarding to see plants grow when you harvested the seeds. There are different methods for collecting different types of seeds, and we’ve detailed pods (like poppies) and fruit seeds here. Pop in if you want advice on other types of seed collection.
On dry days check if pods have changed colour but not yet opened to release their seeds. Lay them out to dry – a warm windowsill or airing cupboard is ideal – and then gently crush the outer pod to release the seeds within. With fruits and berries, collect, mash them gently in a sieve and rinse away the flesh with cold water. Leave the little seeds and pips to dry for a few days.
When storing your collected seeds put them in paper and into an airtight container with something to remove any moisture (like those packets of silica gel that often come in delivery boxes). Remember to label what the seeds are, when you harvested the seed, and then store them at about 5 degrees C. Finally, prepare for the leaves to start falling by netting ponds, covering vegetable crops with netting to stop birds and cleaning out greenhouses and other spaces ready for Autumn to really take hold.