As summer makes way for autumn, days shorten and temperatures are cooler. Colours in the garden are fading, while seeds and fruits ripen. With cooler temperatures, wildlife begins to prepare for winter, fattening up off autumn’s bounty and seeking safe places to roost and shelter at night. Resident birds are quieter now, no longer needing to defend territory and many visiting birds, such as swallows, have begun to migrate south. Peacock and small tortoiseshell butterflies can be seen feeding on nectar while they prepare for winter hibernation in sheds, crevices or tree holes.
In the garden
While September hues are more muted there is still plenty of colour to be found. Gardens with late summer and autumn flowering plants can still look vibrant. Flowers in bloom include the bright yellow daisy heads of the black eyed Susan, Rudbekia; Tulbaghia violacea with delicate clusters of lilac flowers dancing on tall, clump forming stems; the flat headed flowers of the iceplant, Hytophelium sp. (formerly known as Sedum spectible); the star burst thistle flowers of sea holly, Eryngium sp.; the yellow plumes of native species golden rod, Soldagio; the blousy, soft pinks or whites of Japanese anemones such as Anemone ‘Dreaming Swan’ or Anemone x hybrida ‘September Charm’; Asters, Aster frikartii and Aster novi-belgii with their brightly coloured, daisy like flowers, loved by bees and of course the many brilliant Dahlias.
All of these plants provide a late season boost of nectar for insects. If you look closely at these autumn blooming plants you will see they are likely to be crawling with bees and butterflies. Overwintering butterflies, such as the small tortoiseshells, need to take on large quantities of nectar to survive hibernation. Many of the late flowering plants, such as the goldenrod and sea holly, will also have attractive seed heads that can last well into winter and provide seeds and shelter for insects and birds.
Bright berries are appearing on many earlier flowering shrubs such as the firethorns, Pyracantha; Cotoneaster, Viburnum sp and sea buckthorn, Hippophae rhamnoides and many roses have formed colourful hips. As well as adding colour and form to an early autumn garden, these berries provide food for a wide range of birds, mammals and other creatures.
Traditionally gardens were tidied in autumn but this reduces forage and shelter for wildlife. Structural standing seed heads look beautiful covered in frost and will provide food for wildlife throughout the winter. Piles of logs, twigs, fallen leaves and hollow stems provide habitat and shelter for ladybirds, amphibians and other creatures.
Plant spring flowering bulbs
It’s time to plant spring flowering bulbs. Daffodils, crocus, hyacinth and allium should be planted in early – mid autumn to enable them to establish and build energy to flower next season. As a general rule plant bulbs to a depth of about 3 times their diameter with a handful of organic compost added to the planting pit to encourage healthy root growth and sand or grit at the base to prevent rotting. Planting in informal groups of 3, 5, or 7 gives a more naturalistic effect. In larger areas, such as lawns, throw handfuls gently and plant them where they land. If planting daffodils, crocus or other bulbs in grass consider that the foliage should not be cut back for 6 weeks after flowering so the area planted will not be able to be mown during this time. Crocus, allium, snake’s head frittilary and grape hyacinths are particularly good for wildlife, providing early nectar for pollinators.
Cover ponds with a net to catch fallen leaves
For those lucky enough to have a pond, it is a good time to place a net over the top of it to collect fallen leaves from any surrounding deciduous foliage before the autumn leaf fall starts in earnest. Fallen leaves will eventually turn to a silt in the pond, increasing nitrates in the water and risking clouding the pond the following year. It is better to prevent this happening than having to clear the pond of rotting leaves. Use rocks, sticks or pins to hold a reasonable finely meshed net in place taking care not to damage healthy aquatic foliage or tie it higher up between surrounding tougher trunks or stems or well secured canes.
Plant out biennials and perennials
Plant out any biennial plants sown earlier in the year and they will have a head start on those planted in the spring. If you didn’t have time to self sow then it should still be possible to buy plants now. These includes foxgloves, Digitalis sp; wallfowers, Erysium sp; and violets, Viola sp. September is also a good time to plant new perennial plants as the soil is still warm and there is generally more rainfall for them to root in a little before their winter dormancy. Be aware of the eventual height and spread when deciding on an appropriate spot to put them. Be sure to water the plants in well and keep a weather eye out for the possibility of a drier autumn spell in case they need continued irrigation.
Lifting and dividing congested and spreading clump forming perennials when they are not in active growth will reinvigorate them, keep their spread in check and provide new plants to use or give away. First lift the clump out of the bed by teasing all the way around its base using a hand or garden fork whilst applying gentle upwards force to encourage it to lift away from the soil. Shake off excess soil from the roots back into the planting pit. Separate the plant by hand into distinct smaller plants, either tease smaller distinct plantlets away from the clump or pull more firmly on stronger more fibrous rooted clumps. On larger, heavier clumps, use two forks back to back to form a dividing lever to pull apart larger, firmer clumps or use a sharp knife to divide dense and woody clumps. Aim for good sized new clumps with at least 3-5 healthy shoots. Trim off dead or damaged foliage or roots with a sharp clean knife or secateurs and replant the required new clumps in their chosen space or pot up for later use. Add organic matter to the soil, firm the plants in and water well.
Keep collecting seeds for sharing, storing or for planting next season. Try to leave some seed heads on the plants too – they can look very attractive going into winter and provide valuable food for birds and shelter for insects. Store seeds in a cool, dry and dark place. Label the containers with the plant name and date of collection.
Make a habitat box or shelter for hibernating insects
There are many different types of insect hibernation boxes or shelters, many are easy to build, take up very little space and can help beneficial creatures survive the winter. Ladybirds shelter in dead wood, drilling holes in a log and leaving it in a warm dry place, with a roof or cover to keep it dry will create a space for them to overwinter and be ready to tackle aphids in the spring. Twigs and hollow stems, set in a small, simple timber box and hung on a wall or fence may help lacewings that like ladybirds eat aphids. Designs and instructions for making bug boxes, large and small, can be found online.
Gardening tasks in September
- Have a gentle tidy. Remove and destroy diseased foliage and clear fallen leaves if they are in access areas and risk becoming slippery. However leave areas of potential shelter in less disturbed areas as well as healthy stems and attractive seed heads that will provide winter forage for birds and mammals and shelter for insects.
- If planning a bonfire, dismantle the pile and rebuild it in another place before lighting to avoid harming toads, frogs or hedgehogs which may have taken up residence.
- Continue to deadhead to promote a last flush of flowers.
- Plant spring flowering bulbs. As a general rule plant bulbs to a depth of about 3 times their diameter with a handful of organic compost in the planting pit to encourage a healthy root growth and sand or grit at the base to prevent rotting. It may help to use a bulb planter for larger bulbs.
- Collect seeds for next season. Store seeds in a cool, dry and dark place. Label the containers with the plant name and date of collection.
- Cover ponds with a net before the autumn leaf fall starts in earnest. Use rocks, sticks or pins to hold a reasonable finely meshed net in place taking care not to damage healthy aquatic foliage or tie it higher up between surrounding tougher trunks or stems or well secured canes.
- Plant new perennial plants. Be aware of their eventual height and spread when deciding on an appropriate spot to put them.
- Renovate or plant a lawn from seed.
- Relocate evergreen shrubs.
- Divide and replant congested herbaceous perennials.
- Give hedges a final trim before winter.
- Take notes of gaps in your planting and areas that have worked or been problematic to prepare for rethinking in the following growing year.
National Trust: How to Help a Hedgehog and Protect a Polar Bear
A book for children aged 5-8 on wildlife and the environment.
How to be a Bad Birdwatcher
“Look out of the window. See a bird. Enjoy it. Congratulations. You are now a birdwatcher.” A book for lay birdwatchers.
Things to see, places to go
Capital Growth Training: Growing Autumn and Winter Vegetables
This session will go through the best vegetables to grow in our lovely winter climate, while looking at the challenges that growing in winter brings and how to work around them.
5 September 2018, 6pm-8.30pm
The Skip Garden, 1 Tapper Walk, King's Cross, London, N1C 4AQ
Herbal Medicine Workshops: Herbal Tinctures for Digestion
An introduction to tincture making and how to make medicines for internal use at home, led by Phytology Medical Herbalist Molly Maitland.
8 September 2018, 11am-1pm
Bethnal Green Nature Reserve, Middleton St, London E2 9RR
Wildlife Gardening Forum Conference: New Findings in Wildlife Gardening Science
Hear directly from active researchers about new discoveries and current research in the understanding of garden wildlife.
29 September 2018
The Trinity Centre, Bristol BS2 0NW