It looks like we are all in for some rougher weather in the next couple of weeks.
To be fair, we don’t need wall-to-wall sunshine for the sort of jobs we need to do in September – tidying up shrubs, perhaps, planting clematis or repairing bare patches in the lawn…….
Shrubs in autumn
Are you getting a bit itchy about tidying up summer flowering shrubs like Buddleia and Hydrangea as they flap about in the autumn winds? Me too. Do be a little circumspect about this though, because cutting them back now can trigger some fresh new growth which could get badly clobbered by winter cold and weaken the plant dramatically. It’s generally better to leave this job until spring, if you can bear it, especially with Hydrangeas.
I’m actually more gung-ho with Buddleias and Lavateras round here (they grow so readily, it wouldn’t hurt them to endure a little restriction!) – they’ll probably get their usual ‘tidy-up trim’ now and a proper crew-cut in early spring.
Some plants however are rather apt to produce weak, spindly, dead, diseased or simply unproductive shoots right in the middle. The centre becomes matted with this stuff, restricting airflow and causing even more disease problems. In September, have a poke about in the middle of plants such as Choisya, Laburnum, Robinia, Acer etc. and clean out this sort of rubbishy growth.
You can trim back late-flowering shrubs like Fuschia and Abelia in autumn when they have finished flowering (I’m not touching my Abelia yet though – it’s still in full fig, and utterly a-buzz with foraging bees!). Tidy up Lavender, Rosemary and Cistus too (but please be careful not to cut into the old wood of Lavender and Cistus – I killed a fabulous Cistus once by being too harsh with the pruning ☹️).
With young shrubs you’ve planted in the last three years or so, take a critical look at them. I would suggest that you don’t do anything for the first season or two – let them produce all the shoots and foliage they want to. After that time, sort out which are the weakest shoots and cut them out – the idea is to persuade your new baby to be concentrating on developing the strongest shoots that will form the main framework. Now all you have to do is consider when your plant flowers and make a note to prune it straight after that each year – e.g Forsythia in late spring, Philadelphus in mid-summer, and so on.
Just to finish these tips about shrubs, early autumn is THE best time to move evergreen ones – the soil is still warm, and the roots can get nicely settled before winter sets in. Water it well the day before, lever it up with as much soil as possible around the roots, put it straight into its new position, backfill with soil then soak it again. Sorted.
Ornamental grasses
You may have read in last week’s blog about my severe overhauling of several of my flower beds. I’ve been digging out and dividing perennials like a demon, while keeping the roses, shrubs and grasses in situ and adding others. By the way, my long-handled perennial spade has hardly left my hand since I started this work – what a weapon it is! If you haven’t got one yet, please do check them out in our online shop – it’s a game-changer, a bit like our razor-hoe is for weeding.
Anyway. This gardening labour brought me into close contact with my ornamental grasses and reminded me to mention that this is an excellent time to collect seeds of these grasses. They have soared in popularity in recent years but so has the price of them – you could save yourself a lot of money and it’s easy to do:
- Choose a dry day to cut off mature seedheads with a short length of stem.
2. Make a note of the name of the grass on an envelope.
3. Gently pull the seedheads apart, clear away any chaff and seal the cleaned seeds in the envelope.
4. Keep the envelope in a cool, dry place until next spring when you should sow them thinly into modules of peat-free compost.
Gardening shorts
- I’ve been planting some new clematis varieties – this is a really good time to do it. Clematis is one of the few plants that benefits from NOT being planted at the same level that it was in the pot. Position it deeper than that, so that the soil comes right up to the lowest set of leaves. Fork the soil at the base of the deep hole you’ve dug and mix in some compost or well-rotted manure. Soak the hole with water.
Backfill the hole with more of the soil/compost mixture, firm it down, and water the whole site well. If you’re planting your new clematis next to a wall or a fence, dig your planting hole at least 30 cm (1 ft) from it, and position a bamboo cane to guide the clematis stems towards it.
- Keep your lovely autumn dahlias coming by dead-heading them regularly – remember, the pointy ‘buds’ are finished, the plump rounded ones are just coming……………
- Stop feeding greenhouse crops of melons, toms, peppers etc. They need to focus on ripening their remaining fruit now rather than developing more.
- Rake over patches of lawn that got damaged over the summer by flopping plants, the tread of many feet, football goalmouths etc. and sow grass seed there to repair them – it should germinate quickly now the autumn rains are arriving.
There is a small shrub from South Africa that looks exactly like it would love very dry soil but in fact prefers wetter ground, and Louise Sims loves it for its elegant, upright form and pretty flowers. No wonder it’s one of her Great Plants this Month:
Are you preparing to divide perennials this autumn. It’s a pretty physical job but this tool makes it a whole heap easier. Find it in our online shop:
💚 The costs of keeping our site working and safe are going up. We want to go on sharing everything for free without adverts, but if you enjoy our weekly posts, the price of a cup of coffee would be extremely helpful in paying the bills! Thank you 💚
Just click on the image to see if you fancy any of these!
NB If you’re not already a subscriber and you’d like a bit more gardening chitchat from the3growbags, please type your email address here and we’ll send you a new post every Saturday morning.
One reply on “Let’s give shrubs some love! Gardening tips for September”
I remind my (new to gardening) sister in law – when deadheading dahlias, Pointy is Past.