We have had just some seriously blowy interludes here – tail-end of Storm Boris, apparently (no barracking at the back, please) – and it’s a reminder that the year is moving on apace.
The autumnal vibe means there’s all sorts of prep to be done in the garden before the cold sets in, including sowing hardy annuals, tidying shrubs and potting up herbs, amongst other things…
Sow hardy annuals
Hardy annuals are …..well….hardy, which means that they can stand frost. Mostly you would sow them in early spring though, to flower for one summer and die in the autumn. But it’s perfectly possible, even desirable to sow HA seeds now. You get stronger plants and earlier flowers next year. And if you are the sort of person who’s organised enough, you could sow some of the same seed again next spring as well, to keep your annual display going from May to October!
Californian poppies are a good candidate. Also. Ammi (or Orlaya), Cerinthe, marigolds, Malope, Nigella (love-in-a-mist) and lots of other seeds can be treated like this. Just sow the seed into pots of compost in a cold greenhouse or frame. Or simply into raked, clean soil outside where you want them to flower.
I find it’s better to sow into short lines if you’re doing this because the seedlings are alarmingly indistinguishable from germinating weed seeds when they are small! You really don’t see the lines once the seedlings have been thinned in spring and are flowering.
It seems a bit mean, but if you’re growing them in the protection of a greenhouse and they develop some flower buds over the winter, you should snip them off, so that the plants concentrate their minds growing strong roots instead. Plant the pot-grown ones out into the garden or pots where they are to flower, in early spring.
Shaping up the shrubs
This is not generally the time to go bonkers with the pruning saw, and though you may be tempted to hack back all the late-flowering shrubs like Buddleia and Hydrangea, it’s actually better to leave them until early spring because pruning might trigger fresh new growth that will be clobbered by winter cold and weaken your plant.
It could however be a good moment to peer into the centre of shrubs and trees and cut out any dead, diseased or otherwise unproductive shoots and twigs you find. If the middle has become matted with such material, the air flow can become restricted through the plant and more disease problems can result.
Some of the weakest thin branches growing the centre can be cut out and any small branches growing at a daft angle making the plant look ugly. Some things like acers are particularly prone to this sort of growth, but lots (Choisya, Laburnum, Robinia etc.) might also appreciate a once-over round about now.
Divide and multiply
Don’t forget that September is a very good time to divide herbaceous perennial plants. This is a very effective way to a) renovate old clumps so that they flower better, and b) make new plants to grow elsewhere or give away.
If you dig up the clump, you’re likely to find that the middle of it has become woody and unproductive, as I did while I was dealing with Sanguisorba the other day. Discard this section, and hack off the more vigorous sections with roots attached, growing on the outside of the clump. These are the bits that you can replant into good soil now ready to flower magnificently next year.
I always chop the top growth off too, because I want the ‘new’ plant to concentrate on making good strong roots before winter sets in rather than maintaining foliage that will soon die down anyway as the plant enters dormancy.
Ornamental grasses
Don’t do this dividing trick now with ornamental grasses though – the divisions have a depressing tendency to rot in winter damp and chill, so leave dividing these until the spring. You could certainly collect some grass seeds now though of attractive ones such as Cortaderia (pampas grass), Briza, Festuca, Miscanthus, Pennisetum, Stipa, Eriophorum (this is that lovely fluffy-looking hare’s tail cotton grass) and Anemanthele (pheasant grass).
Collect short stems of these on a dry day, clear away the chaff, stalks, etc, and keep the seeds in a paper envelope in a cool dry place (labelled) ready to sow in spring into pots of peat-free compost.
Gardening shorts
- Bring in pots of parsley, sage, rosemary and thyme (tra-la 🎵🎵!!) for better pickings in the winter, and keep them in a cool, bright place.
- You know I’m always on about my perennial spade, well I’ve found yet another use for it – it’s great for clearing moss, weeds and crud out of ancient stone steps – who knew! I don’t know if Adam Frost has used his for that purpose yet, but I do know that it’s rarely out of his hand when he’s appearing on Gardener’s World. The shrub rake is also an invaluable tool at this time of year when there is so much clearing up to be done. We have both these great tools in our online shop – do have a look:
- There you are; I’ve given you a load of tasks to get on with, and I’m sure you can add a load more! But don’t forget to take time to appreciate the special moments of this early autumn season – sunset colours among the flowers ( look at the feature pic this week!), spiders’ webs and heavy dews, the lower longer light of the sun through tree branches – it doesn’t have to be all slog on the downward slope to winter out there!
If you have a garden pond, September is often a very good time to overhaul it as Laura did last year, with excellent results! She’s updated her video on how to go about it with some footage of the finished product:
NB After our very popular piece about Gardening for Well-Being last week, we were invited to talk on this subject on the radio programme ‘Sunday Gardening’ broadcast simultaneously on Radio Kent, Radio Sussex and Radio Surrey. So Laura will be doing just that this Sunday, September 22nd, so listen out for her interview starting at around 11.15.
For those that aren’t familiar with the programme there are more details on how to tune in on their Facebook Page and if you want to submit a gardening query to their friendly experts the new email is Sunday.gardening@bbc.co.uk
Here’s a plant that makes even non-gardeners sit up, according to Louise, our resident plantswoman. It’s a vine, but her admiration for it has nothing to do with grapes……..
Summer’s over – time to tidy up!
While enjoying our lovely autumn, there’s no doubt leaves are starting to build up and parts of our garden are starting to look a bit tatty. This is a fantastic tool for putting that right and keeping your borders looking tidy.
Even More 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 “Prepping and planning – Growhow tips for September”
Thank you for the advice about not dividing grasses in the autumn.