Action for September Borders, ponds and patios
Borders - what to prune now
Trim summer-flowering heathers. Use shears on larger plants but take care not to cut into old wood and take off the faded flowers.
Cut back overgrown climbers. Trim Boston ivy, Virginia creeper and Chinese Virginia creeper as necessary once the leaves have fallen.
Trim soft growth of ivy. Prune away from walls, windows and doors. More severe ivy pruning is best done early next year in the spring.
Trim shrubby honeysuckle. Give hedges a final trim towards the end of September.
Look after your herbs
Tidy flowering tender herbs
Now’s the time to tidy flowering tender herbs such as marjoram and oregano. Cut back the stems to just above ground level. This will give them a good chance to recover with some new growth before the first frosts arrive.
Divide overgrown herbs
Divide clumps of overgrown herbs such as chives, marjoram, mint and lemon balm. This will rejuvenate them and stop them – particularly rampant spreaders like mint – from taking over the rest of your herb garden. Replant the divided sections elsewhere in the garden or grow them in pots.
Potting up and taking cuttings
Pot up herbs such as mint, chives, parsley and thyme to bring indoors or under cover so that you can make use of them over winter – they will die back if left outside.
Take cuttings of woody herbs such as rosemary, bay, sage and lavender. These can all be quite short-lived and so taking cuttings will give you more plants to replace any that are past their best.
Look out for black spot on roses – dark spots with yellow edges or dark blotches. Pick off any affected leaves and collect those that have fallen onto the ground. Throw away or burn the leaves to prevent the disease spreading.
This is a powdery white deposit on leaves, stems, flowers and fruit – it can be a real problem in September. As well as looking unsightly, it can lead to poor growth, dropping leaves and discolouration.
It’s often worse if plants are overcrowded or short of water. Keep plants well watered and try to avoid wetting the leaves. Remove the worst-affected parts of plants.
- Cover your pond with netting to stop autumn leaves falling in.
- Divide overcrowded plants that may be growing at the edge of the pond and cut back dead or dying leaves.
- Prepare gunnera for the coming frosts. Cut off the leaves, cover the crown of the plant with straw or fleece and put the cut leaves on top, weighed down with a few big stones or bricks.
Plant now for spring colour
Plant up windowboxes, pots and hanging baskets for winter and spring colour. We used miniature cyclamen and a flowering hebe and looked for larger examples of those already in flower because plants don’t grow much in lower temperatures.
Pop in spring-flowering bulbs such as tulips to keep colour coming. Add a slow-release fertiliser – see our for Best Buys – and put drainage material such as stones at the bottom of containers so the compost doesn’t get too wet.
Shrubs in pots
Shrubs in container displays such as aucuba and euonymus, and pot-grown trees such as magnolia may well have filled their pots with roots.
Take the plant out of its pot, loosen any compacted roots and cut off those that are circling round the inside of the pot. Repot in a larger container or plant out in the garden.