Lychnis coronaria

We have had three wet British Augusts in a row and I am keeping sane by telling myself that there cannot be much more to come. Those of you on Mediterranean holidays are living in the hot conditions that nearly destroyed my garden in its youth in the 1990s. Those of you with green English lawns to mow will understand my suspicion that nature loves to rain on Saturdays.

In the third consecutive wet August there has been a great rush of green growth and a general levelling up of a season that began in May by being ahead of itself. Fortunately I had dealt with the worst of the untidy growth before rain stopped clipping. If you have not yet cut back all your hardy geraniums that have gone out of flower do the job immediately. The new winners, Rozanne and Jolly Bee, can be left alone as they are still in full flower but the lesser breeds that most of us planted years ago are transformed by a really hard clipping back to the central core, using lawn shears to speed up the job. There is no point in keeping the mildewed old top growth, which has straggled by now all over its neighbours. It belongs on the compost heap and its removal transforms the garden’s look.

I am similarly ruthless to all tall things, like verbascums or foxgloves, which flower before mid-July. A garden still full of deadheads, flopping geraniums and violas and dead spikes of flower on anything from a hosta to a delphinium is one the owner has neglected, pleading the “flowering season”.

Nepeta govaniana

Between the storms plenty of new possibilities have caught my eye. For years I have wistfully remembered monardas, not because their native name is bergamot but because they looked so good in many great gardens, especially in the north of England, which I remember from my youth. They were one of those border plants that always flowered in the first season of planting and were quick to make an impact. They spread out into a mat of roots and brought a fine range of pink, purple-red and deep red flowers to the centre of planned borders at a height of about 3ft.

The problem was that they lasted only for two or three years. I used to think the shallowness of their root-system was the culprit but the greater problem was mildew, which attacked the leaves after flowering. It was such a pest that I gave up on them. Now, new mildew-resistant forms have been bred and in this very wet summer they really deserve their fame. Look out for Monarda Squaw, one of the best, with strong red flowers and a level of health that opens a new era of robustness. Others are coming to the market and if a good garden centre says they are mildew-resistant you can assume it knows what it is talking about.

Even in heavy rain I continue to bless the tall back-row capacity of yellow-flowered Silphium perfoliatum. The family is much more familiar in the US, which is its native home, and I am surprised how slow British gardeners have been to take it up. It is the distinction of my main border in early August and is quite untroubled by rain. Its virtues include its ability to stand as high as 6ft-7ft without any staking. Perfoliatum has particularly tidy glaucous leaves. The rays of yellow flower look a bit like a super senecio with good green backing. It has a slight tendency to run by sending out roots beyond the main clump but it is not at all uncontrollable, unlike the types of helianthus on whose tuber-like roots, cousins of the unstoppable Jerusalem artichoke, I wage a furious war. Hostility is intensified by the fact that I paid good money at a nursery for the tallest and most vigorous spreader of them all.

Jolly Bee

Many of us spend August decapitating or uprooting seedlings of the white and magenta-flowered lychnis, which blow around from a parent and add odd spots of colour where we do not really want them. A few years ago I hit on something far finer, a stray plant with long-lasting, double, deep magenta-red flowers above the usual clump of grey leaves. I showed off about it and then managed to lose it in a wet winter. It seems that it left me for an honorary role on television. A very similar one is now on sale under the name Lychnis coronaria Gardener’s World and, although it is taller than the one I remember, it is an excellent plant that everyone would enjoy. I have put three at intervals in the front row of a shortish border and they have been flowering and leading my eye down the length of the bed since mid-June. It pays to take off the individual dead flowers on the stems but others will be flowering beside them. This new arrival is excellent value and very easy to please.

On one of the wettest recent evenings I consoled myself in the garden of a keen gardening friend, expecting that the rain would have reduced his superior range of plants to a look nearer my own. Sometimes it had but there was enough to remind me to revise my own shopping lists. I cannot compete with his range of dieramas, grown in raised beds of grit and rich soil and admired for their arching stems of flower, never better than on the deeply coloured Merlin and Blackbird.

However, one of his winners is so easy that I keep forgetting to install it, the pale yellow-flowered catmint, Nepeta govaniana. The point about this underexploited option is that it will also flower well in half-shade and does not need the dry, sunny ground with which I wrongly link it. It will even seed itself into new places, looking like a rare form of species nicotiana. I am always struggling to keep up continuity in the shade of east walls or lightly branched trees. The catmint family would be the last place to look but after seeing this yellow one so happy in rain and half-light I have learned from a gloomy evening to look on it with a new eye.