Gardening jobs for September

Harvest crops

When the leaves of your onions begin to flop over, they're ready to harvest. Check them and use any with signs of damage first. Then the rest of the crop can be stored in old net bags, plant trays or even plaited into strings.

Pumpkins and squash should be raised off the ground to ripen in the sun before harvesting. If the weather is wet, cut them early and bring them in to ripen in a greenhouse or sunny windowsill. To cure the fruits for storage, keep them in a warm room for a fortnight, then put them somewhere dry and cool but frost-free.

Early varieties of apples, such as 'Discovery', are best picked and eaten as soon as they're ripe. 

Watch our video guide to veg jobs for September.

Get ready for spring

Spring might seem like a long way off, but September is the perfect month to start making preparations for a beautiful floral display.

• Plant spring bedding, such as pansies, wallflowers and sweet Williams. There should be a good selection of plants at the garden centre. Water them well before planting and give them a good soak whenever the weather is dry to help them establish quickly.
• Buy spring-flowering bulbs. Choose firm, plump bulbs and avoid any with signs of mould. Plant them as soon as possible so they can start putting down roots. The cool, moist conditions of late autumn suit tulips best so wait until then before planting them.

Keep the patio going

Enjoy the summer display right to the end by keeping your containers in shape. 

Deadhead the plants regularly to encourage more blooms. If the weather is dry, give them a good soak and finally, give them an extra boost by feeding weekly with liquid fertiliser; controlled-release feeds will be running out of steam by now.

See our Best Buy controlled-release feeds.

Divide perennials

Autumn is a good time to divide clumps of perennials such as hemerocallis. Lift the clump and then divide it into pieces, either by prising it apart with two forks or cutting it up with a spade or bread knife.

Each piece needs some leaves and roots. Older pieces from the centre of the clump should be thrown away, but newer pieces can be replanted or shared with friends. 

Some perennials, such as sedums, will benefit from being divided every few years to keep the clump growing vigorously.

Veg jobs for September

Even if the weather is still sunny and warm, the nights are colder now and there's dew on the ground in the mornings. Autumn is here and it's time to take stock of the year and tidy up. But there's still time to sow a few select vegetables...  

For our complete guide to veg garden jobs for September, watch our video.