This week, refresh tired-looking herbs, prepare cabbage for harvest, and add a splash of colour to your plot for autumn
Mint is beginning to look tired, so remove a small section of a plant, cut it back and repot into fresh compost. Place on a sunny windowsill to give you fresh mint during autumn and winter. This works with chives, too.
October is also a good time to take bay cuttings from a growing tip around 15cm long. Strip lower leaves and remove the soft tip. Insert into a pot filled with a 50:50 mix of peat-free compost and either sand, grit or perlite. Place cuttings in a protected place, either an unheated greenhouse or against a wall that’s not south-facing.
Check your cabbages
Cabbage white butterfly activity should be low in October, so I remove all the protective netting to allow light and better air circulation around my kales and winter cabbage.
Once the netting is removed, take the opportunity to clear away any dead or tired leaves from around the base of the plants.
As the cabbages hearten up and reach a good size, start to strategically harvest them at intervals along each row – this will encourage better development of the remaining plants on the plot.
One of the many challenges gardeners face is how to keep our plots colourful in autumn. Asters are an incredibly diverse and reliable group of perennials. Commonly known as Michaelmas daisies, many asters now have the botanical name of Symphyotrichum. Most need a reasonable garden soil which doesn’t dry out and will grow in full sun or partial shade.
My top three are: Symphyotrichum novae-angliae ‘Violetta’ (right), which is mildew-resistant and perfect for the back of a border; it reaches 1.5m, is a strong grower and doesn’t require staking. Rich purple flowers appear from September. Aster × frikartii ‘Mönch’ produces masses of lavender-blue flowers and grows to around 90cm tall; Symphyotrichum lateriflorum var. horizontale grows into a dense mass of tiny pink and white flowers to a height of 1m.
October is a great time to take cuttings of buddleia, the aptly named butterfly bush. Find pencil-thick stems, cut a piece about 25cm long, just below a bud at the base and just above a bud at the top. Remove leaves from the lower two thirds of the stem and push six of these cuttings into a 3l pot filled with peat-free compost mixed with a little perlite or grit. You should have lovely, rooted plants by next summer. Buddleia tolerates most soils and has a long flowering period.
Two projects to plan
One of the most beautiful ways of growing a rose is through a tree, achieving a naturally dramatic effect.
The type of rose that you choose will be dictated by the size of tree. Smaller trees, such as birch, cherry and unproductive fruit trees, suit less vigorous climbing roses, whereas more rampant rambler roses suit larger trees and conifers.
I’ve found that by tying a piece of rope into the canopy, then spiralling the rope loosely around the trunk and anchoring it into the soil at the base of the tree, I get something to tie the rose to. Plant the rose on the north or shaded side of the tree as close to the trunk as you can. Dig a hole twice the depth and width of the pot or root ball. Mulch the rose and water well for the first summer or until established. ‘Cécile Brünner’ will reach around 8m; Rosa banksiae ‘Lutea’, suited to larger trees, reaches around 12m.
I like to grow lilies in pots as they provide lots of colour in early summer – a tricky time for creating impact. ‘Mona Lisa’ and ‘Casa Blanca’ are show-stoppers because of their scent and large flowers. Plant each bulb in a small plastic pot then place in a sheltered spot. Once bulbs have emerged and reached a height of 10cm or so, transfer them into large terracotta pots in threes or fives, mulch with gravel and place where they are to flower. By starting bulbs in a smaller pot, you can guarantee that the finished pot will look full.
Tom Brown is head gardener at West Dean Gardens, West Sussex