IT HAS been a beautiful autumn so far. Summer container displays have hung on to the last. You may not have felt able to rip out tender plants still in flower, but now is the time to prepare the pots for winter.
If you used fresh compost in the spring, and there are no signs of maggoty vine weevil grubs, there is no need to replace it; but add a sprinkling of slow-release fertiliser. It is worth raising the pots up slightly to aid drainage, using pieces of tile or specially designed pot feet. Incidentally, the old advice to use broken flowerpots in the bottom of the pot has been shown to make no difference whatsoever to plant health. If that is the one piece of gardening lore you have inherited, go with it if you like; it won’t hurt.
Planting density needs to be higher than for summer displays, as each specimen will not put on much growth. Be generous with plants rather than pots. Favour the completely frost-proof plastic and fibreglass (fake terracotta and lead are surprisingly good these days), and put the rest away till spring. A shallow saucer filled with water could form part of a group of pots and offer water for winter birds.
Unless you are going minimalist, with one block of the same plants, mixed displays benefit from a taller, shrubby element planted centrally or centre-back. Clipped box is the classic example. Viburnum tinus and Viburnum x bodnantense “Dawn” both flower through the colder months, and the latter has the most intoxicating scent.
A daphne (also scented), or a small-leaved hebe such as Hebe pinguifolia “Pagei” also work well. Rosemary, bay, or sage could provide for the kitchen as a bonus. The coloured stems of a dogwood such as Cornus “Midwinter Fire” make a lovely focal point.
Once this “anchor” is in place, plunge bulbs around it down into the loosened compost, aiming for a depth of twice the height of the bulb. Dust them with chilli powder if squirrels are a menace in your area. Then you can overplant with a mixture of foliage and flowering plants.
Aim for different textures: a fern (try Polystichum setiferum); something grassy, such as the sedge Carex oshimensis, or coal-black Ophiopogon planiscapus “Nigrescens”; some broader leaves, such as variegated Arum italicum “Marmoratum”; or a heuchera and a trailer, for which you can’t beat ivy.
Finally, infill with plants that will offer some blooms during our darkest months. Violas are more reliable than pansies: “Avalanche” is particularly good. Primula and polyanthus do not get into their stride until spring is in the air, but some seasonality is no bad thing. You can liven up the show instantly by inserting seedheads such as alliums, or coloured stems cut from a garden.
Shelter from cold and wind will help a container’s occupants. Evergreens go on losing water through their leaves, and cannot replace it if they are in frozen compost. A protected corner may be in a rain shadow; so the odd watering might be needed; but, on the whole, winter pots are a lot less work than their showier summer equivalent.