Provide landing pads for insect pollinators and predators and your garden will be first stop for their services.
Storm Aileen has scooted through, the land is a sodden sponge, and I’m out photographing red admirals in a dry crack between September’s relentless downpours. A whole troupe of Vanessa atalanta seems to have blown in with Aileen: seven, eight – or more? The odd peacock is flashing its airborne eyes at me, but it’s red, black, blue and white wings that fill the warm, sunny interludes of this drowning start to autumn. The usually skittish admirals seem as tinged with soggy torpor as I am; they’ll even let me brush my fingers over their weary wings.
Getting eye to eye with butterflies is one of September’s purest delights; it’s one reason we long for those bursts of delayed summer that send autumn into sheepish, albeit temporary, retreat. Eyeballing butterflies – or bees, hoverflies or anything else you fancy – is far more likely if you ensure you have plenty of what all our airborne insect allies need: landing pads. My garden has been rich in them this summer, and plans are afoot to add more of these pollinator platforms.
My definition of a ‘landing pad’ is any plant which marshals together a large number of its flowers into a solid, organised and flattish head. The big round faces of my sunflowers are not a single flower (like say a tulip), but a compressed collection of smaller flowers or florets, in this case arranged on a green circular disc. So a single sunflower is actually a well-organised gang of smaller florets, each nurturing its own seed (in a pre-evolved life the florets would have been strung out evenly along a flower stem). Nature has upped the odds of pollinating insects visiting sunflowers by compressing their offerings into a big, unmissable and – this is crucial – accessible head that insects can alight on with ease: easy-landing flowers, if you like. A number of other insect-pulling plants in the daisy family (Asteraceae) have evolved in a similar way: think Calendula, cosmos, Doronicum, Echinacea, Helenium, Inula and my heart’s desire, dahlias. It’s my deluge-defying dahlias that are the stage for the vanessas’ current raindrop-dodging antics.
Not all landing pads are engineered this way. Two others which see frantic traffic all summer here are native plants: hogweed (Heracleum sphondylium) and wild angelica (Angelica sylvestris). Instead of packing their florets into a solid disc, clusters of them are lifted up on individual stalks fixed at a common centre, forming a flattish or curved raft of massed flowers called an ‘umbel’, which insects can easily set down on and range over. Their kin are known as the Umbelliferae (or to be really modern, Apiaceae). Think bronze fennel, or carrot, parsnip and parsley; the latter trio make excellent touch-downs if you let them bolt and flower in your veg patch. The herbs sweet cicely (Myrrhis odorata) and lovage (Levisticum sylvaticum) are both perennial umbels. Here, I let hogweed and angelica run free on the wild banks, sowing themselves. They guarantee an airborne pool of beneficial insects, including tiny parasitoid wasps (which inject their fatal eggs into aphids and caterpillars), in the garden all summer long. Big wasps, which devour many plant pests whole, visit them too.
Other plants have touch-down potential. Although Achillea is kin to sunflower, its landing pads are structured similarly to those of the Umbelliferae tribe, and boast real pulling power with honey bees. Ice plant (Sedum spectabile – we’re supposed to call it Hylotelephium spectabile nowadays) is another. Its fleshy heads are at their zenith now, sending bees and butterflies into rapture.
Although it’s too late now to sow annuals such as sunflowers or dahlias, this is a good time to install more perennial plant-once-flower-forever landing pads in your garden or allotment. The soil is still relatively warm, which will encourage pot-grown perennial plants to root out and get a foothold before winter bites (choose peat-free plants grown without systemic pesticides).
All of the floral landing pads on my patch come into service at nature’s pace, but I’m keen to tap into and extend their potential, especially during spring in my greenhouse. There’s a whole stretch when we’re sowing and getting plants going in the relative shelter of a greenhouse (or polytunnel) when – especially in a topsy-turvy season – few insect allies are about to help curtail pests like aphids. That’s when I pray for the first hoverflies to appear, so they can lay their eggs next to aphid outposts (their larvae then eat them), or for early parasitoid wasps to fly on in.
I already utilise one of nature’s finest and first-to-flower landing pads, the dandelion – by growing it in pots. I bring the pots into the greenhouse in January, where they’re gently egged on by the sheltered conditions. Coddled, they flower weeks ahead of the first outdoor plants (which grow everywhere), meaning I can lure early hoverflies into my greenhouse by putting the plants just inside the doors on warm, sunny days. I also stand some pots outdoors in the garden, to give freshly awakened bumblebee queens a pollen/nectar boost. Alongside dandelions, I have pots of autumn-sown calendula (pot marigold); ‘Winter Sun’ can produce its orange pads right through a mild winter, sprinting on in spring.
My plan is to pot up more cultivated perennials to line up alongside my wild ones. One that looks especially promising is leopard’s bane (Doronicum orientale), which flowers in early/mid spring but ought to shine earlier if potted and mollycoddled under cover. It should be a hit with hoverflies, and I’ll plant some for the bumbles out in my perennial beds. If I had soil beds in my greenhouse, I’d plant permanent groups of landing pads near the doors, which you can also do in a polytunnel (in a big tunnel you can mix perennials in among transient crops to encourage a self-contained ecosystem, as savvy organic growers do). But for me it’s pots, peat-free compost and landing-pad-perennials at the ready. The dandelions might feel nudged off the top spot, but they’ll rub along fine.
A rainbow chases off another shower and the vanessas are back, flitting between glinting floral pads. Let the eyeballing commence.
Text and images © John Walker
Find John on Twitter @earthFgardener