Autumn is officially here
In all its golden glory. The ground is wet with dew in the mornings and the garden is covered in cobwebs, but some days may still be glorious and warm. This may be the first month some areas of the country experience their first frosts. The leaves are falling from the trees in abundance and a lot of summer crops are coming to an end.
Sowing and Growing
Collect seeds from summer-flowering plants for planting next year. Or with beautiful seed heads such as alliums, cut off from the plant whole, dry and spray paint in silvers or golds for glorious Christmas decorations. It's also a good idea to leave some seeds in situ in the garden for hungry birds
Plant out the hardy annuals you've been bringing on inside and any biennials still not placed.
Save seed from your favourite plants – it is easy to do and will provide you with plenty of plants to fill gaps or make an existing scheme have more impact. Leave a few seedheads on your plants after they've finished flowering to allow the seeds to ripen, then collect them and store in paper bags in a cool dry place until you are ready to sow them.
Dig up any scented-leaf pelargoniums still outside and pot them up as winter houseplants. Most will remain happily on a sunny window ledge for much of the winter, to be cut back early next spring.
Bulbs and Tubers
You can continue to plant spring bulbs in the still-warm ground, to give them the longest possible growing time ahead of next year.
Alliums are also happiest planted while the soil is still a little warm in early-mid Autumn, in contrast to tulips, which benefit from going in to the ground when the temperature has dropped (when the diseases and fungus that they are prone to during the warmer months have died off).
Plant peonies this month as well, and established peony plants should be pruned shortly after the first frost.
Brighten up shady bits of your garden with spring-flowering, shade-tolerant bulbs. Go for snowdrops for January and February, followed by Anemone & narcissi for March and April, finishing with bluebells in April and May.
If we have early frosts, remove dahlia and gladiolus bulbs and tubers from the ground, cutting back their stems to approx 5cm from the roots first. Leave the bulbs somewhere warm and dry for a couple of days. Then store in dry compost in a box lined with newspaper, or in a pot, somewhere warm and dry, until spring. Alternatively, mulch your dahlias in late autumn under several inches of mushroom compost or similar and just clear this away once the worst of the frosts are over in the spring.
Lift and divide large clumps of crocosmia, and replant into freshly prepared soil. If you have any spring bulbs in storage that you lifted earlier in the year, now’s the time to check them over before replanting. Dispose of any that are showing obvious signs of rot, or that feel soft to the touch.
Pot up roots of lily of the valley to provide fragrant winter flowers. Any spent compost from containers of summer bedding can be spread around the borders to use as a mulch.
Plant new amaryllis to give you beautiful flowers for winter and early spring. Plant them firmly, cramming the soil around the bulb. Amaryllis like their soil rich, but exceptionally well drained.
Plant some mini iris (Iris reticulata and Iris histrioides) for pots inside, cramming them into pots with the bulbs almost touching. Planted now, they will be in flower in February when forced on a sunny windowsill.
PERENNIALS, SHRUBS AND TREES
Pruning and Tidying
Keep weeding. Perennial weeds may pull out easily now, but make sure that you don't leave any of the root to overwinter!
Bring tender plants, eg. pelargoniums, in out of the frost and begin to cut them back.