Persicaria are rampant ground cover plants, considered by many gardeners as much a nuisance as weeds. But here Richard Orton of Lewis Cottage, near Spreyton, argues that these invasive plants can be very welcome in a large garden and can even have a place in smaller gardens. He also provides some tips on what to be doing in your garden in the coming weeks.
Persicaria are a fabulous group of long lived, durable plants with dock like leaves that are topped with masses of generally upright, narrow, almost poker like flowers for a long period over summer, in various shades of red, pink and white. Happy in most soil types, some will make significant clumps over time. Most like a sunny open aspect, but many (such as P.bistorta superbum) will tolerate some light shade.
P.wallechii is one of the tallest (up to 2m) and in my view one of the most attractive, but will outgrow its welcome if left unchecked. The pure white flowers in late summer give off a heady honey and almond scent. At Lewis Cottage we have it in an isolated bed to restrict it.
At the other end of the scale is P.orientalis, an annual variety that is perfect for smaller gardens. It goes by the wonderfully romantic name of “Kiss Me Over The Garden Gate”. Easy to grow from seed, it will self seed freely in well drained soil.
The tall narrow flowers of Persciaria lend themselves to the planting scheme known as ‘prairie planting’ mixing wispy grasses and late-flowering perennials in large drifts to create a naturalistic appearance. Varieties such as the tall P. Alba, deep currant coloured flowers of P.Blackfield or orange/pink flowers of P.Orangefields really come into their own.
Not all Persicaria are grown for their flowers; some having very insignificant flowers are grown for their coloured leaves. P. Red Dragon is one of the most popular of these with its deep claret-coloured leaves acting as a perfect foil in a mixed border. Its sister plant P.silver dragon has paler leaves with much less of an impact.
P. runcinata Purple Fantasy is dramatic,with its purple striped leaves shaped almost like a perfect V. It spreads like crazy creating a delicate blizzard of stems clambering through the border. If it gets too much, chop it right back to the ground and watch it revive over a couple of weeks.
P.virginiana Painter’s Palette always divides opinion. Its variegated leaves and rather gangly habit makes it less popular than most Persicaria but it works well for lighting up a dark space, as does P.Golden Arrow with its lipstick pink flowers and chartreuse coloured leaves.
Despite their reputation there is a Persicaria suitable for every garden, just do the homework to find out which is best for yours.
Jobs to be getting on with in the next month:
- Prune summer flowering shrubs, such as climbing hydrangeas, once the blooms are finished.
- Dead-head annual bedding plants and perennials to encourage them to flower into the autumn and stop them self-seeding.
- Cut back faded perennials to keep borders tidy.
- Cut back herbs to encourage a new flush of tasty leaves you can harvest before the frosts.
- Collect ripe seeds and store them for next year. Leaving some seed heads in place can be attractive and allows the plant to self-seed in the surrounding soil.
- Mow meadows now to help scatter established wildflower seeds.
- Take cuttings of your favourite tender perennials such as pelargoniums to propagate them for next year.
- Water sweetcorn plants regularly and feed with tomato food to get the best cobs.
- Apply a high-potash fertiliser such as tomato food once fruits start to form on peppers, cucumber and aubergine plants.
- Limit the fruits on a squash plant to about three, but make sure they are well established before pinching out the surplus.
- Spring-sown carrots and beetroot will be ready to harvest now, but can be left in the ground to keep growing.
- Lift and dry onions, shallots and garlic once the foliage has flopped over and yellowed.
- Harvest French and runner beans little and often to prevent them from setting seed.
- Scoop floating weed and algae from ponds.
Further information on Lewis Cottage garden can be found here
