By Jackie Hunt, Turn End’s Gardener
Well, we have certainly been blessed with an Indian Summer this year! Unusally warm temperatures and low rainfall mean that I have delayed many autumn jobs. The weather is forecast to become a little cooler and wetter in October, so I have a long list that I’ll be hoping to be able to tackle this month:
1. Lift and divide and make new plants
Autumn is a good time to divide herbaceous perennials that have finished flowering and are now putting their energy into developing roots. Many herbaceous plants benefit from division every two to three years to keep them healthy and vigorous. It is also a great way to make new plants for elsewhere in your garden or to share with friends. Pick a day when the soil is dryish and easy to work (but when decent rain is forecast or you’ll need to keep remembering to water!). Cut back flowered stems and gently lift the clump with a fork and shake off excess soil. Gently tease apart individual plantlets or clumps, such as Pulmonaria, Ajuga, Geranium and Epimedium. You may need to use two forks back to back to split up large clumps of fibrous rooted plants such as Hemerocalis (day lily), or a spade or knife to cut up woody Hellebores and fleshy Delphiniums. Replant as soon as possible and keep well watered. You can also pot up and grow on divisions, overwintering them in a frost free place.
2. Give your lawn some TLC!
If your lawn has suffered from this prolonged dry weather and wear and tear, early autumn is a good time to undertake some renovations. The grass will have time to respond before temperatures fall and growth stops. If you have a problem with moss, you may like to apply a moss killer – we use a combined moss killer and autumn feed (follow the manufacturer’s instructions for application method and timing). Autumn feed is higher in potassium and phosphates to encourage grass health, winter hardiness and root growth. When the moss is brown or blackened get a good work out by using a spring-tined rake to scarify, which is giving the grass a really good comb to remove the dead moss and debris (or if you have a large lawn, you can hire or buy a scarifying machine). You can then aerate compacted areas by spiking the ground with a garden fork. Where grass is sparse, sprinkle with grass seed before finally top dressing with a mixture of three parts loam, six parts sharp sand and one part compost. Work into aerated areas with a besom broom or back of a rake. As autumn progresses you should also raise the height of cut on your mower and reduce frequency of mowing.
3. Plant bulbs for early colour next year
I am always in awe of the spring flowering bulbs, battling through winter’s frozen soil to bring such joy and colour early in the year. We love trying new bulbs every year. Spring flowering bulbs should be planted in autumn and Narcissi (daffodils), Crocus and Hyacinths are best planted by as early as you can in autumn. Many hardy bulbs originate from places with warmer, drier summers than ours, so choose a warm, sunny site with good drainage. Buy firm, plump and healthy looking bulbs and plant them as soon as possible – they may flower less well if stored for a long time. Most bulbs look best planted in decent sized groups. Check the planting depth on the packet, but most bulbs are planted at a depth about three times the height of the bulb. Plant with the pointed end facing up and at least twice the bulb’s width apart. We like to add bonemeal to the planting hole because it provides Phosphorus to encourage roots to form. Bulbs also make a great display in containers – we use a mix of two parts loam, one part compost and one part grit. Keep slightly moist and place in a sheltered spot over winter, and you may like to cover with netting to stop squirrels or mice tucking in!
4. Sweep up leaves and make nutritious leafmould
You know autumn is well and truly here when the leaves start falling and blowing into little piles around your garden. Clear them up regularly and add to your compost heap. If you have nice small, soft leaves from trees such as oak, beech or hornbeam you can collect them to make leafmould, which is great for improving soil or as potting compost. Tougher, bigger leaves such as horse chestnut, walnut and sycamore are best shredded first before using to make leafmould. Conifer needles and evergreen leaves such as holly and Aucuba are also best shredded , and then added to the compost heap rather than used for leaf mould. You can also collect leaves with your lawn mower, which shreds the leaves and adds nutrient rich grass clippings to your leafmould. Place your leaves in a bin liner, moisten them if they are dry, and pierce holes in the bag. Then tie them up loosely and stack them up out of sight – they will take up to two years to rot down.
5. Bring in tender plants and wrap up delicate ones
It seems impossible that it will ever turn cold, but October is normally the month when I expect our first frosts. Before the first one, bring in your pots of tender plants. If you have large pots that you can’t bring inside, try to move them to a sheltered spot near the house and wrap up well in horticultural fleece or specially made jackets (both of which you can buy at garden centres). You can also give a nice winter coat of fleece to slightly tender shrubs in borders such as Olearia and Myrtle – I make a simple frame of canes then wrap round 2-3 layers of fleece and secure with string. Protect the base of shrubs and the crowns of slightly tender herbaceous plants with a thick, dry mulch. You will also need to lift tender plants such as cannas as dahlias. When the first frost blackens them, cut back the stems to about 10-20cm. Carefully dig them up with a fork and remove loose soil. Plant cannas straight away in pots or trays of coir, sand or composted bark and kept just moist in a light, frost free place such as a greenhouse until next spring. After lifting, dahlias should be stored upside down for a few weeks to dry off. Brush off any further dirt, then bury them the right way up in trays of dry sand or dry compost with just their stems showing. You can store them in a frost free place such as garage or shed.
6. Order seeds to sow next year
Just as the garden is going to sleep, it is exciting to plan what you can grow from seed next year. We like to order tender annuals to grow in pots and to fill in gaps in the borders, such as Ipomoea, Cosmos and Nicotiana. I have also just sowed hardy annuals such sweet peas, which I will over winter and will hopefully get growing away quickly next year. Also collect seed from your own garden plants on a dry day. Keep each type of seed in a labelled and dated paper envelope and store inside a tin.
Jackie Hunt has been the gardener at Turn End since 2010.