Tall summer volunteers

Saturday, 16 January 2010

Cleome hassleriana, left, with Salvia Indigo Spires, right

No, I'm not talking about those handsome volunteer lifesavers at the beach in summer, but about some good-looking annuals from the plant world. Descendants of original plants I sowed 15 years ago, they appear of their own volition in my garden every spring from seeds shed the previous autumn - hence the term 'volunteers'. They have become the stars of my summer garden, giving a feel of abundance and spontaneity in borders which might otherwise have been dull and contrived.

Such happily self-seeding plants are not recommended for tidy gardeners who like to be in total control! From year to year, you'll have no idea where they will appear, and few take too kindly to being transplanted to a 'better' spot. It is a matter of culling out the seedlings that really are in the wrong location and allowing a lucky few to grow to maturity in their chosen places. Most are tough plants, which will grow in indifferent conditions, but all will respond gratefully to a little extra care. Rigorous deadheading of spent blooms is a no-no if you want subsequent generations of plants to appear! Mulching of areas where you don't want them to pop up is wise. None should be allowed to escape into bushland or pastures.

Amaranthus caudatus

The most statuesque of these plants is often known as love-lies-bleeding (Amaranthus caudatus, ht 1 - 1.2m), which can assume the dimensions of a small shrub in a couple of months. Its plush burgundy tasselled flowers arch from the top of the rhubarb-coloured stems like a floral fountain. It brings a dramatic, tropical effect to summer and autumn borders and looks stunning with dark-leaved companions such as Alternanthera or Canna, as well as rich purple or blue flowered Salvia. A beautiful purple-leaved form exists: I am not keen on its more upright flowers but I love its foliage. Amaranthus thrives in a sunny position and can cope with dry conditions. Be sure that you are in love with it before you plant a single, tiny seed: because once you introduce it to your garden, it will be there every summer!

Cleome hassleriana

Another giant enjoying the same sort of growing conditions is the spider flower (Cleome hassleriana, ht 1 - 1.5m). Above bold, palmate leaves, rounded heads of whiskery pink, white or lavender blooms like friendly flower people are held on increasingly long necks as summer progresses. They provide a superb background mass of colour and exotic form over an extended period. If you tip-prune them when the seedlings are small, a more branched plant will result, with multiple blooms.

Atriplex hortensis var. rubra

In moist, fertile soil in a sunny spot, red orach or mountain spinach (Atriplex hortensis var. rubra) may grow 1.2 - 2m tall; it will be shorter in less favourable conditions. Its sumptuous purplish-red, arrow-shaped foliage is its main attraction, the flowers being insignificant. However, when its purple seedpods develop, these are very decorative. The leaves are as effective in combination with the blue, pink or lavender flowers of a cool-coloured garden as they are with hot oranges, yellows or reds. When you tire of it, you can eat the plant's leaves in a salad!

Verbena bonariensis

Butterfly-attracting Verbena bonariensis (ht 1 - 1.5m) is regarded as a weed by some gardeners, but few other plants have the ethereal grace of its tall skinny stems topped with dainty lilac-purple posies. It looks best at the front edge of a border, to break the monotony of low plantings without obscuring other plants behind it. It also looks effective grown with ornamental grasses to create a meadowy look. It will grow simply anywhere, in any soil, but does best in full sun. I cut mine back by half periodically through summer, which gives them a new lease of life; some plants survive through winter, but there are also plenty of new seedlings each year.

Take a chance on one or more of these annuals next summer!