My garden’s blue period

In the garden as in life, some days are good, some not so good. In southern England, the Saturday before last was heavenly. On September 23 I was free to enjoy ideal conditions for gardening and I learnt as I did so. Lessons from this heaven may inspire you too.

The sight of the moment was one of my favourite Michaelmas daisies, gleaming with flowers and teeming with bees and butterflies. Anyone can grow Little Carlow, the superb aster which is now classified as a Symphyotrichum. I started with one plant of it 20 years ago and now have dozens more, even after giving many away. Its deep electric-blue flowers indeed gleam in sunshine, developing small yellow centres when they have been pollinated.

Yellow-centred Little Carlows abound now after a Saturday of intense activity by bumblebees. This lovely daisy grows about 3ft high. As the stems are wiry, it usually needs to be staked lightly from August onwards. It is best in the dry soil I can easily give it. I divide it in spring, not autumn, and check it for its one enemy, early season slugs. They can shred its narrow leaves when they appear in April. Otherwise, Little Carlow is indestructible, unless the soil is heavy and waterlogged.

In the Saturday sunshine my Little Carlows were not only humming with bees. They were graced by autumn migrants, the lovely Red Admiral and Painted Lady butterflies that were docking on the heads of flower. Recently, scientists discovered that Painted Ladies fly into Britain in great clouds from Morocco and sub-Saharan Africa, travelling at such a height that no home secretary has monitored this mass migration. Wonderfully, we have no control over our butterfly borders.

On arrival, Painted Ladies fan themselves and feed on superb non-native plants of British autumns, especially Little Carlow asters and the brilliant blue “plumbago”, Ceratostigma willmottianum, which originates from China. They do not feed on nearby nettles and British wild flowers.

Glancing sideways from my pink camouflage, a copy of the FT Weekend, I enjoyed a late breakfast in the garden and watched two dragonflies land on the table. They gave each other the cold shoulder and kept away from
the nearest Red Admiral butterfly. Looking beyond them, I enjoyed two happily evident facts. One is that my garden is now in its blue period. The other is that plants which I feared to have died in the winter are still returning to green growth.

Three weeks before, the main borders had been yellow on yellow. Tall Rudbeckia laciniata Herbstsonne was showing bold reflexed flowers at a height of 6ft. Next to it I had planted a tall yellow helenium whose flowers have a contrasting brown centre, Riverton Beauty, up to 5ft high on dry soil. Individually I recommend these two fine plants for August to September, easy choices which flower profusely, but the pairing was an accident. Haters of strong yellow in a garden would find it too much, but I like it. It has faded and given way to drifts of blue.

For years I have been growing a tall thin-stemmed aster with spires of lavender-blue flower. I have watched it flourish while its botanical name changed, becoming Symphyotrichum cordifolium Chieftain, no less. I give it high marks because it reaches 5ft and needs no staking in a well-planted border. It also seeds if it is happy. My Chieftains are so happy that they have seeded more profusely than I can control. The seedlings show in late spring wherever they have found space, even in the middle of other plants’ clumps. Never mind: in late September they turn the border into a blue haze without any attention from me.

Painted Ladies fly into Britain in great clouds from Morocco and sub-Saharan Africa, travelling at such a height that no home secretary has monitored this mass migration

Three years ago, in the interval between lockdowns, I introduced a like-minded daisy, formerly an aster, now Erigeron annuus, which I had seen used to good effect in the Lancashire borders of the top garden designer Arabella Lennox-Boyd. It too is a tall one, up to 5ft and, as it dies away after flowering, it is a blessing that it seeds freely and multiplies year on year.

I have it near a fine pale sky-blue aster with little flowers, Hon Vicary Gibbs, which is sold, like all the best asters, by Old Court Nurseries, near Malvern, who will send young plants out next May if they are pre-booked now. The combination of this white aster with the pale-blue one near the lavender-blue Chieftain looked dreamy on a September Saturday under a blue sky, broken by white clouds. I recommend them all.

In July I was still afraid that the winter had cost me my shrubby pink-flowered indigoferas and, nearer ground level, the hardiest of diascias and a rose-red little flowering shrub, a scutellaria, among my alpines. Taking time to look and think, I found all three alive, the diascia being Denim Blue, whose flowers begin as a shade of purple, and the scutellaria being suffrutescens Texas Red, another magnet for bees I much recommend.

So many plants this year have sprung back into green life after the midsummer discard that I heard TV pundits recommending. Nothing has revived dead hebes and cistus, but other damage is less the more time passes. Even the invaluable Bidens aurea has restarted, the tall relation of the half-hardy orange bidens we grow in pots. It reaches 5ft and flowers from September onwards, an excellent pair for tall daisies in their blue mist. It derives from Mexico but it survived last winter’s night of -12C.

Among the butterflies and a blue prospect, I set about clearing the inevitable weeds, never shy to breed in a wet summer. Out too came self-seeded mats of a purple-flowered origanum, a cousin of the marjoram beloved by cooks. It is another bee-friendly plant, but it strays far and wide from its parents. The state of the soil was as ideal as the weather, damp and readily workable as seldom in recent dry autumns when a chisel has seemed more apposite than a trowel. I enjoyed reopening patches of bare, clean soil, one of gardening’s pleasures, into which I sowed hardy annuals, an autumn trick that is still timely.

In our longer milder Octobers, hardy annuals will germinate in time to be thinned before winter. Frost permitting, they will then flower in May, giving us blue cornflowers, lilac corncockle and scarlet poppies when wallflowers are going over.

Clear a space and sow a packet directly into the soil. It is a gamble, one which triumphed in 2022 but failed after the frosts in 2023: I use the Californian bluebell, deep-blue Phacelia campanularia, whose seeds are now available by the 2,500 for £1.39 from Amazon.

Serene skies and workable soil give gardeners calm and confidence. In late afternoon, white-flowered autumn colchicums appeared in the lawn while I was working: they are an excellent addition to any autumn garden. As I rechecked my weeding, another beauty had opened, this time prematurely, a dark-blue flower on a mat of Gentiana acaulis.

Enjoying the wet and the sudden sun, it had jumped the calendar by six months, rounding off a day of delight with a prequel of what it will do in spring.

A perfect postscript to a perfect day.

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