Gardening Job Checklists - September

What to do during September in your garden and greenhouse.

Sow hardy annuals, such as cerinthes, ammi, scabiosa and cornflowers, for flowers early next summer
Lift gladioli corms, dry them off, then store in a frost-free shed or garage over winter
Plant wallflowers, pansies, forget-me-nots and other spring bedding in pots and borders
Collect ripe seeds from your favourite flowers and store in labelled envelopes, ready to sow in spring
Plant up containers for autumn interest, using cyclamen, heathers, heucheras and other colourful bedding plants
Bring any houseplants that you moved outside over summer back indoors, before temperatures start to drop
Lift, divide and replant congested clumps of perennials, such as achilleas, once they finish flowering
Apply vine weevil control to pots if plants show the tell-tale sign of notched leaf margins
Fill any gaps with late-flowering perennials, such as sedums, to provide nectar for pollinating insects into autumn
Plant spring bulbs, including crocuses, daffodils, hyacinths, bluebells and snake's-head fritillaries in pots and borders
Take cuttings from fuchsias, salvias and pelargoniums
Keep summer bedding flowering in hanging baskets and pots until the first frosts by deadheading and feeding regularly
Trim conifer hedges to neaten them up and control height
Leave sunflower seedheads in place for birds to feed on

Plant up pots for Autumn interest and colour.

Sow hardy greens, such as kale, land cress, pak choi, mizuna, lamb's lettuce and mustard, for winter pickings
Prune out all the fruited canes of summer raspberries, cutting down to the base, and tie in new canes to supports
Pot up herbs, such as chives and parsley, and place on a sunny windowsill to use during winter
Start sowing hardy varieties of broad beans and peas for early crops next year
Plant onion and shallot sets in a sunny spot, 10cm apart, with the tip just showing above the soil
Cut away any leaves covering the fruits of pumpkins, squash and marrows to help the skins ripen in the sun
Plant saffron crocus bulbs (Crocus sativus), so you can harvest your own saffron this autumn
Pick apples and pears before the wind blows them down, and store undamaged fruits if you can't eat them fresh
Store chillies by threading the stalks onto strong cotton or wire and hanging up to dry somewhere warm and dry
Cut off trusses of unripe outdoor tomatoes before the weather turns cold, then ripen them indoors
Lift maincrop potatoes, dry off and store in hessian or paper sacks, in a cool, dark, well-ventilated place
Complete summer pruning of both free-standing and trained apple trees, to encourage good fruiting in future years

Summer prune apple and pear trees

Plant prepared hyacinth bulbs in pots or hyacinth glasses, for fragrant indoor flowers at Christmas
Take down greenhouse shade netting or wash off shading paint by the end of the month, as light levels start to fall
Stay vigilant for pests and diseases in the greenhouse, and treat any you find immediately
Plant dwarf spring bulbs in pots, including irises, crocuses, chionodoxa and scilla, for early flowers
Pot up tender perennials, such as fuchsias and osteospermum, from summer displays and bring indoors before temperatures drop
Repot moth orchids after flowering if they look like they're about to burst out of their pot
Water houseplants less frequently and move them off particularly cold windowsills at night
Plant hippeastrum (amaryllis) bulbs in pots for spectacular flowers over the festive season
Plant Anemone De Caen corms for a vibrant indoor display in early spring
Pay close attention to greenhouse ventilation, shutting vents on cool nights
Check greenhouse heaters are in good working order
Maintain good plant hygiene, picking off faded blooms and dead leaves before fungal diseases can take hold
Look out for forecasts of early frosts and be ready to bring tender potted plants under cover
Move potted peaches and nectarines into a cool greenhouse or porch

Pot up Hyacinths for fragrant indoor flowers.

Rake thatch from lawns, aerate well-trodden areas by spiking with a garden fork, and re-seed bare patches
Put netting across ponds to stop autumn leaves falling in and rotting
Water autumn-flowering asters regularly to deter mildew
Clean out water butts and check downpipe fittings in preparation for autumn rains
Remove duckweed, pondweed and algae from water features and ponds
Check that tree ties and plant supports are firmly in place, ahead of any autumn gales
Wash and disinfect bird feeders and tables to maintain hygiene
Collect fallen leaves to store in a chicken-wire cage or bin bags to make leafmould
Hunt for rosemary beetles on lavender and rosemary, picking off the striped metallic beetles and their grey larvae
Collect up and bin apples, plums and pears infected with brown rot, to reduce the spread of this fungal disease
Order bare-root fruit trees to plant later in autumn or winter
Check roses for signs of fungal diseases, such as blackspot, and pick off and bin all affected leaves

Pick off and destroy any leaves with blackspot