September in the garden: plant, clean & enjoy the late summer colours

Stake Dahlias and Chrysanthemums 

If you grow dahlias or chrysanthemums, remember that, especially when in flower, they are bulky plants and liable to wind damage. To avoid them being blown over, make sure they are well supported with stakes – bamboo canes are ideal. 

Winter Bedding Plants

Don’t forget that there are great bedding plants that you can plant now that will flower through winter. They’re especially good for cheering up the tubs and containers on your patio, or for window-boxes.

Sow Late Salads 

You can still sow the seed of quick growing salads and radishes for picking in a few weeks, but they will grow even better if you cover the seed with a cloche.

Maintain Pond Plants

The foliage of many pond plants will be beginning to die off. If possible, clear it out so that it does not decompose in the water. Similarly, remove the dead flowers from water lilies. This will help keep the water clean and healthier for your pond life. Keep on clearing dying foliage through the autumn to avoid having to dredge next spring. 

Take Cuttings 

It’s a good time of year for taking cuttings from a variety of perennials. You should take your cuttings from the new shoots of the plant that have not produced any flowers – called non-flowering stems.  

Trim Lonicera Hedges 

If you have evergreen or deciduous lonicera hedges in your garden, this is the time of year to give them their main annual clip – to maintain the shape, and to encourage new growth for next year.  

Get Ready to Leaf Mould 

Collecting leaves is an essential autumn job, but you should make use of your work and start making leaf mould. Make sure you have got something ready for collecting and holding your leaves. 

Care for Camellias 

Camellias are making their new buds for next year’s flowers now. So, if you grow them in pots or other containers, make sure you look after them with regular water and perhaps an occasional feed to guarantee success. 

Prepare for Tree Planting 

The best time to plant trees is between autumn and early winter. Preparing the ground a few weeks in advance will pay dividends. In the area where you intend to plant, fork over the ground, and dig in some good compost or leaf mould for soil enrichment. 

Planting Bulbs in Borders 

It’s bulb planting time, and it’s important to appreciate just how adaptable bulbs are. Lots of different bulbs are ideal for growing in borders to make a spring display before shrubs come into flower.  

Trim Hardy Perennials 

There aren’t hard and fast rules about autumn tidying and cutting down hardy plants in borders and containers. Some, for instance ones that are not very hardy, are probably best left with a bit of protective growth to help ward off frost. However, many of the hardiest, for instance hardy geraniums, will benefit from a close trim now. It will mean they produce vigorous fresh growth and form a nice shape next year. 

Clean That Greenhouse 

This is time to give your greenhouse a good wash off, especially if you have covered the glass with summer shading. Plants, seeds, and cuttings will benefit from the maximum amount of light possible during the coming months, and clean glass makes a big difference. 

Plant Roses 

Most roses come in the containers in which they’ve been grown so that they can be planted at most times of the year, but to fit in with the plant’s natural cycle, planting in the autumn is probably best. It means you’ll allow the plant the winter to settle its root system and become established before the first season of growth. 

Clear Up 

The season for garden debris, leaves etc. is about to begin, and it’s important to remember that if you have any kind of fruit trees or bushes, you should keep clearing up excess fruit to minimise the risk of disease spreading. However, don’t forget to leave a few for the wildlife to enjoy during the winter months.  

Dig the Veg Garden 

If you have a veg garden – or smaller patch – it is likely you have got some areas of bare earth after summer crops have finished. This is the ideal time to dig it over thoroughly – before autumn rain or frost make the job harder – and dig in a generous amount of enriching manure.

Lift Your Potatoes 

You have probably eaten all the potatoes you have been growing from the spring, but if you have any still in the ground, or grow them specifically for winter use, they should be lifted and stored now. If you leave them in the ground the steadily dropping soil temperature, autumn rains, and possible early frost are all threats. Dig them up with a fork, separate the potatoes, and leave them on the surface for a couple of hours to dry off. They should be stored in a damp, dry, and frost-proof place. 

Early Sweet Peas 

Gardeners are competitive and love being one step ahead, so if you have a cool greenhouse or somewhere else suitable, try sowing some sweet pea seed this autumn and growing the plants on through the winter. You will be able to boast your first blooms early next summer, while most people are still looking at tiny buds. 

Lead Image: Leigh Clapp

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