Foxgloves are at their best this month and once again, in our garden, they have bagged places rather better than the ones I put them in. They seed copiously into the chip-covered paths up the bank and every autumn I shovel up seedlings and replant them at the edges of our plot. They are supposed to do that handshake-with-the-wild thing you read so much about – provide a transition between the garden and the landscape.
Instead, they roar up into vast spires in the flower garden, where I have not noticed their rosettes swelling between the iris and the spurges, the thalictrum and the angelica. And when I do notice them, I haven't the heart to pull them up. So having melted quietly away in the darkish, dampish corners along the hedges where I thought they should be, they queen it in the borders instead.
These are not even fancy foxgloves, just plain old purple (and occasionally white) ones. But they are clever. They've put themselves in good company: with the acid yellow-green heads of the short-lived perennial spurge, Euphorbia oblongata; with the elegant pale green stems of the caper spurge (Euphorbia lathyris); with the dark purple flowers of columbines.
The two spurges and the columbines also brought themselves to the party without an invitation. "Go away," they are all shouting. "We can get on very much better without you." That's probably true, but each year, I learn something from the self-seeders. A good stand of purple foxgloves has joined a group of alliums and some thalictrum in another part of the garden (I did plant both of those) and the three make good companions. But it would be even better with a more interesting foxglove. So this week I have been sowing seed of 'Pam's Choice' (Thompson & Morgan £2.19) to give flowers next year.
It's a selection of the wild foxglove (Digitalis purpurea) with big creamy-white flowers spotted and blotched inside with deep burgundy, a stunning thing when it is growing well. Like the wild foxglove, it is a biennial, making a rosette of leaves in its first season and running up to flower in its second. June is the best month to sow a wide range of biennials such as evening primrose, sweet Williams, sweet rocket, honesty and little pom-pom daisies to line a path or fill a pot.
Spring, of course, is the major season for seed-sowing, but this June slot tends to get forgotten. Yet biennials can provide big features in a planting – foxgloves 5ft high, sweet-smelling rocket 4ft high, honesty with flat disc seed pods that you can use in winter flower arrangements. You get a lot of plant for your effort.
And the effort is actually very little. You can sow in a drill in the open ground, as you might do with vegetable seed. As with any seed, you need to prepare the ground properly, raking it, knocking out any lumps, and damping down the earth if it seems dry. If scrabbling cats and birds are a problem, protect the drill with netting or a length of chicken wire.
When the plants seem reasonably advanced (with leaves a couple of inches long) ease them gently out of the soil and plant them in fresh ground, with enough room for each plant to develop into a meaty rosette. Then in early autumn, you can shift them into their final positions. Both these shifts are easier after rain, when the ground is moist. But whether it has rained or not, you should water the plants well after you've replanted them.
I prefer to sow seed thinly in 13cm (5in) pots, where I can more easily keep an eye on them. They'll germinate in 2-3 weeks. Before the seedlings get too big, prick each one out into a 8cm (3.5in) pot and grow them on in a cool place. By the time the roots have filled the pots, you may already have identified places where you can set the plants straight into their final positions. If not, grow them on in larger pots or in a spare piece of ground until that time comes. They need to be settled in by early autumn. Because the leaves are poisonous (the heart drug, digitalis, comes from foxgloves) rabbits leave them alone. So do slugs and snails.
This is the basic routine for all biennials, all of which should be sown by the end of the month. Foxglove, honesty and evening primrose are all enthusiastic self-seeders. If you don't like that kind of thing, uproot the plants before the seedpods ripen. Self-seeding white foxgloves gradually revert to purple, but you can tell them apart even at the seedling stage. Plants that are going to bear white flowers have none of the purple staining on leaves and stem that the purple-flowered ones have.
Anticipation is one of the great delights of gardening and next summer seems far enough away from the disasters of the present (lemon verbena not coming back to life, badger rootling among some rare trilliums, beetle on the lilies) to encourage dreams. Scanning seed catalogues gives the same vicarious thrill as reading recipes. You mull over the ingredients, imagining what the final dish will be like. Dilettantes stop there. Real enthusiasts go the whole hog and try the thing out for themselves.
Each possibility raises yet more possibilities. Perhaps there should be white sweet rocket among the shuttlecock ferns of the hammock house bed? The scene up there could do with an uplift after the brunnera has finished its blue spring thing, and the planting in that bed is deliberately planned in big waves of only a few things: shuttlecock fern, evergreen mounds of shrubby hare's ear (Bupleurum fruticosum), brunnera and the fabulous soft shield fern, Polystichum setiferum 'Bevis'.
If you are growing from seed, you can afford big waves of things and the rocket (Hesperis matronalis 'Alba') costs just £1.69 for 250 seeds (Thompson & Morgan). The standard version is mauve, but it is a muddy colour. The white sings out more clearly. It is perfectly happy in semi-shade, which is a useful trait, and insects love it.
Evening primrose (Oenothera biennis) I've never sown, but I've never been without it either. It's an incredibly successful biennial, native to the eastern states of the US. The flowers (a soft yellow) have a few built-in disadvantages. They are short-lived and they are not at their best during the day. But they smell gorgeous, like many plants that peak in the evening. I try and pen them up in the furthest, wildest part of the garden, where they wrestle for space with seedlings of the herbaceous geranium 'Brookside'. Maddeningly, since all that space is left to its own devices, it's been looking rather good this month. It's yet another case of "Go away you meddling idiot".
Thompson & Morgan, Poplar Lane, Ipswich, Suffolk IP8 3BU, 08445 731818, thompson-morgan.com