As I write this it seems to have been raining for the last couple of months, the hot and sunny start to summer just a distant memory. September is, meteorologically at least, the start of autumn but, fingers crossed, it’s still possible to get some warm and sunny spells to make up for all the recent downpours. Keeping on top of maintenance jobs is, possibly, slightly easier at this time of year because things are slowing down as days shorten and temperatures decrease.
I know there is a trend towards not having lawns in gardens but, for many, a healthy lawn is the perfect setting from which to admire the more planted areas of the garden. Now that the risk of summer drought has passed, but while temperatures are still high enough to ensure successful germination, it’s a good time to give your lawn some ‘tlc’. If your grass is generally ‘OK’ then simply raking out the moss and dead grass, ‘thatch’, may be all that is required. If raking / scarifying your lawn reveals thin, bare, patches then overseeding with new grass seed is an easy way to improve the sward. Reseeding, or overseeding, is best done while the ground is moist but not during periods of heavy rain as this may wash seed away before it gets a chance to germinate.
Cutting the lawn as short as you dare, before doing any overseeding, means that it can be left uncut for long enough to allow germination of your over-sown grass seed before cutting again. Cutting at a slightly higher setting, after rolling the new seed into the lawn surface, should allow the newly germinated grass to get established while still keeping the lawn looking good. The application of a proprietary autumn lawn feed should improve the existing grass without harming the delicate new seedlings although it’s probably best to avoid using a ‘weed and feed’ on establishing lawns, or over-sown areas, because grass seedlings are more sensitive to the selective weed killing chemicals than ‘mature’ grass.
On the subject of killing weeds; September is generally the recommended last month to apply non-persistent, translocated, herbicides based on ‘glyphosate’ because it’s specific mode of action, disrupting the chlorophyll production in green plants, requires that the plant is in active growth. If not absorbed into a green plant it just breaks down in the soil, which is why it is ‘non-persistent’. I understand that a lot of gardeners prefer not to use any chemicals in the garden, each to their own, but chemical control of weeds is a necessary evil in gardens where there aren’t enough hours in the day to hand weed every last inch of bare soil.
In newly planted borders, where ornamental plants have yet to fully cover the naked ground, the use of glyphosate, between your planted plants, is pretty essential. Hand weeding will be necessary close to your establishing plants, because you cannot risk spraying them with weedkiller, but a combination of hand weeding these ‘intimate’ areas plus weed killing the ‘wider’ areas should keep everything under control.
Areas that are ‘clean’, i.e. free of weeds, can be treated to a generous application of an organic, sterile, carpet of mulching material which will help to reduce the amount of weeds that re-establish. ‘Mulch’ is a term that can be applied to anything that covers the ground to suppress weeds and therefore includes inert, but totally unnatural, coverings like woven plastic membranes; naturally occurring, but also inert, substrates such as gravel; naturally occurring, but not inert, substances based on composted organic matter. The latter needs to have been composted at high enough temperatures to kill all pathogens and weed seeds, to make it sterile, or else it could actually make your problems worse by introducing a whole new horror show of weeds or diseases.
Mulches based on organic matter will break down over time, that’s because they are not ‘inert’, and will require reapplication if they are to remain effective. Generally, the coarser the material in the mulch the longer it will last without needing to be topped up, so chipped or shredded bark will last longer than ‘council green waste’, but the coarser the material the less aesthetically pleasing it will be in an ornamental setting. A coarse bark mulch isn’t the best addition to a traditional herbaceous border—but is perfect to make paths through a wooded area or as a way to disguise the aforementioned, but ugly, weed suppressing fabric.
I probably should have written about hedge cutting last month, August, because that’s the traditional time to tackle evergreens, predominantly yew, but it’s still not too late in September so that any cut specimen has a chance to recover before winter arrives. Psychologically there is something very pleasing about ‘sharpening up’ the more structural elements of the garden so that the summer shagginess is removed and formal hedges, or clipped specimens, have their shapes restored before the garden descends into autumnal decay.
Before I got sidetracked into mulches and hedge maintenance I had planned to dedicate the whole of this article on bulb planting—an absolutely fundamental part of a successful garden. Ideally you will have already ordered your bulbs by now, assuming you are doing it online, because the most popular varieties sell out quickly and also because the sooner they are ordered, the sooner they arrive, and the sooner you can get them in the ground. The less time the bulb spends out of the ground, considering that they will have been harvested many weeks ago, the better able it is to establish in your garden (or pots, containers, window boxes etc.). The exception to this ‘plant now’ rule being tulips which are best left until later, even into November, to avoid the pathogen which causes ‘Tulip Fire’.
The best advice I can give about bulbs is that nothing succeeds like excess. Huge drifts and carpets of a single type of bulb, especially if you are naturalising them, is generally better than little splodges of mixed up varieties. Cramming them into containers, an idea rebranded as ‘lasagne planting’, is the order of the day and, unlike planting them in beds and borders, keeping to the recommended planting depths (generally included on the packaging or supplier website) is less important because they are programmed to flower in the first year no matter how badly you treat them.
There are just too many choices, when it comes to autumn planted bulbs, to make specific recommendations and bulb suppliers are pretty good when it comes to recommending which bulbs are best suited to which situation. One general rule is that the smaller the bulb the closer to the soil surface it needs to be planted, and vice versa, so this is an important factor when considering what to plant in existing borders; tiny bulbs are most suited to situations where they won’t be disturbed by future border maintenance. A stonking big allium (e.g. Allium giganteum) can be planted deep enough that it needs never to be disturbed again and will just go from strength to strength, year on year. I find, in fact, that alliums can practically become weeds, albeit very welcome weeds, in established borders because of their ability to both self-seed around and also propagate themselves by bulb division—that’s something to look forward to.
