Gardening Tips

Are you feeling seedy? Gardening tips for September

Image of Elaine

Most of us have experienced some fierce storms this week and guess what?!  Most of us got (very) wet AGAIN, as well as windswept. 

Oh well, it’s still far too early in the year to curl up in front of the fire with a copy of Gardeners World magazine and a glass of red, so let’s get on with some autumn gardening tasks like cutting back climbers, planting autumn bulbs and…

Going for a hack

Lots of climbing plants have revelled in this summer’s damp conditions and gone mad.  Ivies, honeysuckles, wisteria, rambling roses, Virginia creeper……..they all seem to have put an extra yard of growth this year beyond the usual.  You may have been away on holiday as well, just to add to the jungly chaos of your return.  September is a good time to tackle them. Most have finished flowering, and much of the hard labour of summer is behind us so we’ve got a bit more time for a serious tidy-up. 

September is a good time to give beauties like this Jasmine ‘Clotted Cream’ a good prune


I had just such a jasmine (J. officinale ‘Clotted Cream’) which had gone berserk and outgrown its space at least five years ago.  I think it still had lots of its sweetly-scented flowers but they were so high up or obscured by the mountains of foliage, that the plant might just as well NOT have had them.  Time to wield the secateurs with determination.  For all the daintiness of its blossom, jasmine is a tough plant and can take a serious cutback, and that’s what it got!

Just got to tackle my overgrown mountain of jasmine!

It had covered so much ground with its dense branches, I was able to rake over all the soil revealed by the pruning, and sow grass seed into at least 3 square yards.  

The resulting hacked-about shrub is not frankly a thing of beauty at the moment, but that’s okay.  All will be well next summer.  

Also cut out the flowered shoots of rambling roses and tie in the new ones, trim back all the shoots on wisterias to two buds, cut unruly honeysuckles back hard (another very tough plant generally), tidy up star jasmine (Trachelospermum) and chocolate vine (Akebia quinata). It’s just a case of telling them that they’ve had their fun and now you’re taking back control…

Feeling seedy

Lots of plants will be going to seed now, and it feels almost criminal not to be collecting this marvellous free harvest. I’m thinking of things like foxgloves (Digitalis), love-in-a-mist (Nigella), sunflowers (Helianthus), Cosmos, Allium, honesty (Lunaria)Aquilegia, Verbena bonariensis, poppies (Papaver), Primula.etc. 

Seedheads of plants like foxgloves will provide you with such bounty

Seeds from ‘species’ plants will reliably result in plants very similar to the parent plant, but seed from cultivars (when a species plant has been given a specific name) will be much more variable. You’ve enjoyed the lovely flowers and now they are giving something more – the means to make more gorgeous plants!

You need a dry, windless day for this job, and the seed-pods need to be ripe, which generally means they have changed from green to brown. The trick is to collect them when the seeds have ripened but before the plant has dispersed them. I hold a paper bag or an envelope underneath the seed-pod and give it a tap. If a few seeds fall out, they are ready to harvest.

Collecting seeds using an envelope or paper bag

Don’t use plastic bags for seeds because you want any remaining moisture to dry up. Seeds can easily rot if they are enclosed in plastic.  Then snip off the entire seedhead and let it drop into the bag. Do scribble on the envelope what plant you took the seedhead from – I have an embarrassing number of envelopes of seeds from…who knows where!

Leave them in a dry airy place for a week or two to dry out completely. Then, sift out the seeds from the pods, bits of stem and chaff. If you leave this on, it can be another way that the seed is affected by damp or mould. Primula seed can be sown fresh, but otherwise transfer the seeds to neat little white envelopes, LABEL THEM (!), and store them in a wooden box in a dry, cool, dark place until springtime.  If you have a lot of seeds, please do think about donating them to a seed-distribution service, or share them with friends.

Gardening shorts

  • Take advantage of garden centres selling off their garden furniture stock cheaply to make way for all the Christmas winter wonderland stuff – you can pick up some very good bargains!
  • Great friend of the 3Growbags, Bill Tait, has some brilliant advice about what to do with gladioli bulbs in Autumn:

‘Cut them about a foot (30cm) above the ground and leave them there until late October/ early November. Then lift them, remove as much soil as possible and store them somewhere cool and dark.

‘By December the remaining foliage will have dried out and is easily removed from the top of the new corm. Carefully, ‘unscrew’ the old corm off from the undersides and then store the corms in a cool, frost-free place. If it’s too warm, the corms will break into growth prematurely. Discard any corms which look dodgy.

‘Often, there are two or three new corms growing from an old one so who needs to but new corms each year?’

Look after gladioli bulbs over the winter months for glorious colour next year
  • Youngest Growbag Caroline has survived clematis wilt! As I said in my last Grow-how column, Autumn’s a great time to plant new clematis but you must remember to plant them quite deep and here’s why:
Caroline’s clematis suffered a bad bout of wilt…

In August Caroline sent a baleful WhatsApp saying ‘Wot has happened to my clematis?’ Well it got attacked by clematis wilt, that’s ‘wot’. I told her to cut off all that dead top growth and because she had earlier followed my ‘big sister’ instructions to plant her clematis at least two inches lower than it was in its original pot, her plant was able to create new shoots from those buried stems, and it’s looking frankly FINE now. It’s so important to encourage the younger generation, don’t you agree…

…….and now it’s absolutely fine!
  • Finish digging up your potato crop. The longer you leave them, the more likely they are to be attacked by slugs and other critters.
Dig up your potato harvest before the slugs start getting interested
  • I have a little gardening tale. We had a huge tree branch come down on a small island of shrubs in the lawn in June, and it broke many of the branches of a white buddleia. So we cut the whole buddleia down to near the ground, and thought ‘oh well, if it doesn’t survive, it was only a buddleia’. It has thrown up splendid new shoots and is now in full flower, covered in fluttering insects at least six weeks after other buddleias were in bloom. I can see how being able to make buddleia flower later, would really help extend the nectar season for butterflies, hoverflies etc. I might do it again next year!
You can make a buddleia flower later to keep the butterflies and hoverflies happy well into autumn – who knew!
  • Laura’s been planting autumn bulbs this week – watch her video on how she did it…..

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Rudbekias are going great guns right now but it they’re a bit hefty for your planting style – what about this little belter? It’s one of Louise’s Great Plants this Month

If you’re preparing to plant your crocuses or iris reticulata – this is the tool for you – in our online shop now

By the3growbags

We're three sisters who love gardening, plants and even the science of horticulture but we're not all experts. We'd love everyone even remotely interested in their gardens to be part of our blogsite.

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