Enjoy your garden’s spring glories – while keeping an eye on late summer

I’ve always had the gift and the curse of an overactive sense of foresight. It means I’m good at planning things, but maybe quite anxiety-inducing to be around. This week’s column is very much the product of both, but I’ve been encouraged to write it by having near-identical requests from friends arrive at the same time of year, two years running: each was planning an important celebration in their garden (a wedding and a naming ceremony) in late summer, and wanted them to be in full bloom for the occasion.

As a royal parks gardener once said to me: “If it could be May for ever, I’d be happy.” It’s a glorious month: everything is soft, fresh and dewy. There’s enough anticipation in the ground and the air to inspire a daily inspection of what’s arrived overnight. The days are long, but nothing feels overbearing yet. The thud and the inevitable horticultural failures of midsummer, the dry ground and drying lawns, are on the distant horizon. Lovely May.

The anxiety-inducing planner in me wants to heartily encourage you to pause this reverie to imagine August or September. You stopped watering regularly a few weeks ago, when you went on holiday. The slugs returned during that miserable grey bit in July. But more than this: your garden looked heavenly in May, and so you considered your job done and didn’t want to believe there were four months of good garden time ahead. Now all the flowers have gone over. It is somewhat depressing.

But it doesn’t have to be. Now is the time when you can give a gift to your future self and add plants that will offer late summer colour.

It perhaps isn’t surprising that I tend to make gardens that look best in late summer – I’ve thrown my own life-event parties then too. I love that last-chance-saloon feeling that arrives with the autumn equinox; I love adding plants that catch September’s spiderwebs and sticky sunsets.

Here are some guaranteed bangers: Japanese anemone; Agastache; Achillea; Hylotelephium (or sedums); Salvia (they’ll keep blooming into November); Altheas, I have the smaller, more ditsy A. cannabina and its half-sisters, what I think of as the posh hock, Alcalthaea suffrutescens ‘Parkfrieden’ and ‘Parkallee’, in both the gravel bed, where they romp away, and the shadier beds. Persicaria are reliable doers in beds throughout the summer, their elegant foliage politely filling in gaps, but P. amplexicaulis shoots out long floral spears in deep pinks and reds, or white (‘Alba’).

These are my favourites, but I want to impress the need to find some of your own. By now you’ll have the makings of a colour palette, and an awareness of where the gaps in your beds are; it’s not too late to plonk some 9cm pots in and make your future self grateful.