What to Do in the Garden in August
Living North's gardening expert Ross Pearson shares his advice on what needs to be done in the garden this month
Autumn is not here, it’s not even close, but it has looked up from whatever it has been doing and started to think about putting its coat on.
I find August a strangely emotional month in the garden. After the long build of spring and early summer, the perpetual hopefulness of it all, the endless planting and staking and waiting, you have arrived. Everything that was promised in those seed catalogues back in January has now, more or less, delivered. The dahlias are hauling themselves skyward in great explosions of colour, the herbaceous borders are shoulder-to-shoulder with flower, and the sunflowers are nodding from behind the fence like large, cheerful neighbours who have had a very good summer indeed. There is nothing left to anticipate. You are, as the phrase goes, in the thick of it.
Which means there’s also a small, persistent voice at the back of my mind that’s already thinking about what comes next. I try to ignore it until at least the third week of August. There’s pleasure to be taken here, and I intend to take it.
Rudbeckia
If I had to identify the single plant that earns its keep most reliably in a late summer border, the answer would come back quickly and without hesitation: rudbeckia (Rudbeckia fulgida var. sullivantii ‘Goldsturm’, if you want to be precise about it). Other plants have had a better summer elsewhere in the garden; the thalictrum performed beautifully in June, the echinacea has been extraordinary, but nothing has the sheer, uncomplicated generosity of rudbeckia.
It wants practically nothing from you. A decent soil, a reasonably sunny position, and the occasional acknowledgment of its existence. In return, it will pump out those black-centred, golden-rayed flowers from July right through October, and look more cheerful doing it than anything else in the border. It also combines with almost everything. The deep purple of Verbena bonariensis behind it. The warm terracotta of Helenium ‘Moerheim Beauty’ beside it. A stand of ornamental grasses catching the breeze in front. Rudbeckia is the plant equivalent of someone who gets on with absolutely everyone and never causes any trouble at the party.
Plant it in autumn or spring in free-draining, reasonably fertile soil. Divide clumps every three or four years to keep them vigorous because they spread steadily but never aggressively. Unlike some perennials that sulk if you look at them wrong, rudbeckia seems to take division as a personal challenge and come back stronger.
Take stock
August is an excellent month to sit down in the garden with a cup of tea and a notebook and write down what has worked. Not to make anything better right now, it’s far too late for that, but because the things that you resolve to change in September are almost always forgotten by March. Write it down. The corner where nothing thrived. The combination that looked terrible. The variety you will never grow again. This is genuinely useful horticultural work, and it counts even if it involves sitting in a deckchair.
Collect seed
The dahlia seeds are not worth saving (the offspring will be unpredictable), but annual cornflowers, nigella and calendula will come remarkably true and reward you generously next year for the 10 minutes spent collecting them into a brown paper bag. Wait for a dry morning, when the seed heads are fully brown and papery, and label everything the moment you collect it. The confidence you feel in August that you will remember which is which in February is entirely misplaced.
Take cuttings from tender perennials
Pelargoniums, salvias, osteospermums – any plant you have been nursing through the summer that cannot survive a northern winter in the ground. Take semi-ripe cuttings now and pot them into gritty compost. They will root in three to four weeks and can overwinter in a cold frame or cool greenhouse, giving you next year’s plants for nothing.
Earth up celery
If you are growing trench celery, give it its final earthing up now, leaving just the tops of the leaves exposed. The process blanches the stems, softening both the colour and the bitterness, and the results are so dramatically superior to anything shop-bought that it seems almost unfair to compare them. Tie the stems loosely with string before you earth up to keep them bundled and upright.
Sow overwintering onion sets
Japanese overwintering varieties (‘Senshyu Yellow’ is a reliable one) can go in from late August onward. They will establish before the cold closes in, overwinter as small plants, and race away in spring to give you a harvest four to six weeks ahead of your spring-sown crop. It is a modest act of foresight that pays back handsomely.
Check squash
If your summer has been anything like mine, the courgettes will have gone entirely off script by now and you will be excavating vegetables the size of small submarines from beneath their enormous leaves. Lift the developing fruits off damp soil by resting them on a tile, slate or straw. This prevents rotting on the underside and also makes you feel very professional.
There’s a saying we hear all too often as we creep ever closer towards shorter nights and cooler days: ‘It’s all downhill from here’. It’s not meant as a complaint. It’s uttered the way a fell-walker might say it, at the summit, whilst looking out over a beautiful valley. There is pleasure in the descent too, and the light on the way down is different from the light on the way up.
I have been thinking about that phrase a lot lately, standing at the edge of the borders in the early morning with the golden light doing its thing. The season is at its fullest. The garden has delivered everything it promised. There is a kind of peace in that, if you can stop yourself reaching ahead to the next thing.
August asks you to be where you are. The borders will not be like this in October. The ducks, who have no opinions whatsoever about the turning of the seasons, are demanding their breakfast with considerable urgency. The plum tree is finally ready to harvest.
This is the summit. Enjoy the view.
