It’s such a wonderful time in the garden as the weather cools and we (hopefully) start to get some rain. But it’s also incredibly busy and the myriad of jobs can seem overwhelming. We created this list to help prioritise and balance our efforts between current season tasks and preparing for future seasons.
1) Autumn Flowering Plants
Dahlias
• Deadhead regularly for ongoing flowers
• Early autumn fertilise (I use sudden impact)
• If you want to save seed, stop deadheading 6 weeks before season end so seed can develop (for me that is the week before Mother’s Day so 23rd March)
• Keep corralling so big plants don’t blow over in high winds
• Photograph flowers, check labels and correct any mistakes!
• Watch for powdery mildew – remove foliage if isolated
• Cut for vases and enjoy.
• Once they finish flowering, leave to die back. If very heavy rain is forecast, cut back green growth and lift dahlia clump.
• Into winter, dig and divide tubers (or leave to overwinter in the ground).
Heirloom Chrysanthemums
• Earlier in autumn, take the last set of cuttings from non-flowering stems.
• Tie up and corral to a stake for support as the plants get bid.
• Disbud for larger flowers. I disbud some and allow sprays of flowers on other stems.
• Fertilise as buds start to appear (I use sudden impact granules or seasol foliar spray)
• Enjoy the late season colour and the flowers for Mother’s Day
Seed Saving
• Save seed as plants go dormant. My favouite plants to save seed from (throughout the year) are: dahlias, Italian ranunculus, chocolate lace flower, sweet William, sweet pea, sea holly, echinops, echinacea, hollyhocks, queen anne’s lace).
General Maintenance
- Remove any diseased plant material and bin (don’t put on the compost heap)
• Leave seedheads to feed overwintering birds and plant matter so beneficial insects can shelter.
• Keep weeding – easier when the weeds are little – and hopefully before the weeds go to seed.
• Mulch to help smother weeds.
• Add compost to new and existing beds.
2) Planning for Winter and Spring
Sowing Seed
• Once the ground is slightly damp, direct sow seed of larkspur, foxglove, delphiniums.
• In trays, sow seed for biennials to flower from winter to late spring (e.g. honesty, wall flowers, hollyhocks)
• In trays, sow seed for winter flowers (e.g. ornamental kale, stocks, snapdragons). Protect from the Cabbage White Butterfly until the weather cools and they disappear.
• In trays sow seed for next year’s perennials (e.g. seaholly, echinops, rudbeckia, echinacea). If you get heavy frosts and don’t have a greenhouse, buy plants or do this in early spring.
Spring Bulbs
• Start to order your spring bulbs in late summer. Italian Ranunculus, Ornithogalum, Anemones (Mistral are the best), Watsonia, Cottage Gladioli. Tulips for pots.
• Plant spring bulbs as the weather cools (typically from late March) to overwinter in ground.• Plant garlic cloves around your flowers for companion planting.
Propagation
• In late summer to early Autumn take cuttings of hydrangea and viburnum.
• Every 2-3 years, divide perennials such as alstromeria, crocosmia, hellebores, geranium, salvias, ornamental grasses, bearded iris and sedum. If the plant is still flowering or actively growing, wait until spring.
Planting Out
• Autumn is the best time to add new plants to your garden. Every year I add South African and Australian natives to our flower farm tree line. Also hydrangea, viburnum, astilbe, hellebores, salvias, clematis, geraniums, etc (the list is long!)
• Order bare root roses if you haven’t already and plant out in winter.
Enjoy autumn in your garden.