What to do in September
Gardening in September
September can be a very busy time in the garden and yet also very relaxing as there is not much of a rush to get anything done. Although there is a great deal of putting to bed, trimming and pruning and general tidying up to be done, very few of the jobs at hand have a tight deadline and so a gardener gets a chance to enjoy the last bright and hopefully warm days of late summer, early autumn without having to rush around madly.
If you have some patches which looked a bit bare and miserable last spring, now is the time to think about putting in some bulbs. All kinds of bulbs for spring colour can go in in September and it is a good idea to have a careful look at the heights of the flowers and the exact time they flower before planting. Some of early ones such as chionodoxa not only give your garden a bit of a lift after the darkness of winter but also spread like mad, so be sure to leave them plenty of room. Planting bulbs is the job many gardeners like the best – the trick is to forget where you put them, so you get a lovely surprise in spring! One tip for anyone with squirrels or mice problems – plant a few holly leaves with the bulbs to give any hopeful snackers a surprise as well.
Many of the jobs the garden will give you to do in September are to do with keeping it tidy and clean. If you leave old flowers on roses and other shrubs they will waste energy setting seed but not only that but you will be encouraging mildew and other diseases which will overwinter if it turns out to be mild so that you start the next spring with problems already in place. Trim back any spindly growth on shrubs and trees to keep a compact shape, but make sure that the centre doesn’t get too dense. Plants need light and air to stay healthy and if the middles get too crowded the branches will die back and you will get at best an ugly lop-sided plant, at worst a dead one. If you wish to save some seed though for next years sowing do so then when the seed has been collected trim the plant back or remove if its an annual.
There won’t be swathes of fallen leaves yet, but it is still good practice to keep the garden free of trimmings and any fallen fruit or twigs. If the autumn turns out to be too wet for too much gardening, these will lie over the winter and can again cause mildew and damping off of plants.
In the vegetable garden you should be still getting harvests of summer vegetables and the early winter ones may be ready now; September can be a really bumper time for the allotment gardener or anyone who has a vegetable patch, no matter how small. If you have an area you can have under cloches or as a small cold frame, spring cabbage and cauliflower can be sown in September. A few winter lettuce will make a nice change in your salads in the dark days to come and they can go in now as well, as can broad beans and peas for next year – choose an early variety.
If you are planning to store any of the harvested fruit you have picked you will have to learn to be strict with yourself and discard anything that is damaged as it will contaminate the other fruit and you will lose it all. If you have a lot of fallen apples or other fruits, freezing them as a cooked product is the best way to make sure you don’t waste anything. If you have been growing strawberries, you will probably still be harvesting some late varieties and of course they don’t freeze well. Making excess fruit into jam is one way of keeping the fruit through the winter, but eating them warm from the September sun is even better! You can pick the last few berries while you are working on the strawberry patch making new plants for next year from the runners.
The colours of September are beautiful, with golds and oranges the predominant shades, along with the lovely smokey grey/blue of Michaelmas Daisies. Autumnal plants tend to be tall as they reach towards the weaker autumn light, but there are some lovely little surprises at ground level such as the hardy cyclamen hederifolium which will start to come through before the end of the month. If you have planted these under trees, be careful when you mow towards the end of September so they are not cut down; because the flowers come through before the leaves they are not always that obvious. And if you haven’t planted any – make sure you do it now for next year. They are so pretty and a welcome splash of colour as the days get darker. You can buy them as corms or sometimes in the green.
If you have been thinking about planting a new lawn and haven’t got round to it, September is really the last chance this season. If you leave it any longer you won’t have a chance to give it that essential first cut and the weak new blades of grass will be very prone to mildew. Before you do cut that brand new grass, make sure that the mower is really sharp, or you will just tear it up. You will have to make sure that the new area is protected well. Leatherjackets are near the surface in the autumn and birds, especially starlings, can play havoc with a new lawn as they dig for them.
On any lawn, new or established, you will probably find that there will be a lot of worm casts. Worms tend to be nearer the surface in autumn than in summer – many people think they like the warmth of the summer but in fact it is moisture they go for, not heat so they are deeper down in June, July and August. When they come back up, their casts can be a problem, especially on a thinner lawn. Brush them off before they can get trodden in, or you will get bald patches. The same, sadly, goes for moles – if you have just enjoyed a nice molehill free summer, prepare to repel them again in September; if you have a mole problem where you live, this is when they come back with a vengeance.
Ponds and pond plants
If you have a pond, there is loads to do in September. It needs a thorough clean out and you should really take the opportunity to really thin out the oxygenators and any plants which are crowding the water. In any pond a good rule of thumb is that less than 50% of the surface should be covered by broad leaves such as water lily. Plants like iris and bulrushes can be very invasive and although it always seems a shame to thin out lovely things like flags, it really has to be done, especially if you have fish. The water can get very hard for them to tolerate if it is too crowded by vegetation. If you like to encourage wildlife to your pond, don’t be too drastic, as they like cover round the edge, but too much debris in the bottom makes the environment too unhealthy and eventually even the less choosy pond life will go elsewhere, if it can.
Plan for next year and cuttings
September is primarily a month when the gardener gets a chance to have a critical look at the garden while there is still time to do something to improve it for next year. Trees and shrubs do well when planted in September because they have a chance to make some root growth which protects them from wind rock in the winter. You can also take semi-ripe cuttings to bring on for planting out next spring. If you have plenty of room for over wintering cuttings, you can take fuchsia and geranium cuttings from all your favourites and have lots of plants for filling in gaps in the spring or to exchange with friends.
Frosts are not that common in September but you should keep an eye out on the forecast just to be sure. The season of mists and mellow fruitfulness really describes September to a t and is almost the perfect combination of looking forward to the new season and enjoying the last fruits and flowers of the summer just coming to a close. With roses and raspberries still going strong, and the first autumn crocuses and cyclamen beginning to show through the grass, September is where summer and autumn meet with the very best of both worlds. Even the most reluctant of gardeners should enjoy gardening in September.