Lovely lobelia for autumn gardens

Although most people know lobelia as a blue, pink or white-flowered bedding or container plant, it has some stunning relatives. Bedding lobelia is a small plant of bushy growth, ideal for window boxes and hanging baskets. It is rarely taller than 20cm or longer than about 40cm when trailing down.

Although it flowers profusely all summer, it is usually cast in the role of a colourful filler, ideal for setting off bigger flowers such as petunia or geranium, but not a star in its own right. Nothing wrong with that, of course, but the difference between this little plant and its elegant bigger cousins is dramatic.

The border lobelia can reach a height of one metre or more in really good soil, although it is usually a bit less than that. In complete contrast to the low-bushy habit of the bedding lobelia, these flower stems stand bolt upright, striking spires of small flowers. The individual flowers are not much bigger than those of its smaller cousin, but they are arranged in a dense spike. Border lobelias bring intense colour in late summer and early autumn – as vibrant as that of the dahlia and lending the same smouldering look.

The colour range is nowhere nearly as wide as the dahlia though and is limited to red, pink and purple. Most kinds are bright cherry-red or rich-red in colour and some have deep beetroot-red leaves. These were bred from North American species and are about 90cm tall. Cherry Ripe has rich cherry-red flowers set against green foliage that has a touch of a dark red flush. Dark Crusader has dark red flowers against dark red-purple foliage.

Bee’s Flame is a very well-known hybrid with bright scarlet flowers, dramatically set off by deep wine-red foliage and stems.

Fan Deep Scarlet has rich scarlet-coloured flowers and Fan Blue has deep-blue flowers. Fan Lachsrosa is a lovely salmon pink. The Fan Series is available as seeds from some seed houses. The series is of mixed colours and should be sown indoors in a propagator, in spring. Vedrariensis is a beautiful, vigorous variety with dark purple flowers and it appears quite a lot in gardens. Pink Elephant has somewhat paler, purple-pink flowers, a real beauty, but it does not seem to be around as much these days.

These plants are at home in moist ground and they grow very well in areas that have heavy soil. The soil needs to be opened up with plenty of organic material, to improve fertility and retain moisture. Lobelias can be grown with their roots in water and they are quite tolerant of some light shade, but their colours look better in sunshine.

The large-growing species Lobelia tupa, from South America, reaches one and a half metres, with spires of dark red flowers. It has large grey-green leaves that wash out to honey-yellow and pink in autumn. The plants can be propagated by division in spring. Use three or more clumps to increase the effect. The plants are hardly noticeable before they flower, but be warned that slugs are fond of the leaves.

Dig out docks

Docks, or dockings as they are known in some parts of the country, have been having a great surge of growth in recent weeks, with the plentiful rain and good, warm spells. This large weed often suffers from drought in the summer months because of its large, broad leaves, but it can quickly recover when rain returns. It can appear in flower beds, shrubberies and the fruit and vegetable areas. The ground is relatively soft now, which makes it much easier to dig out docks – roots and all. Loosen the soil around it with a digging fork and when the weed gives up its grip, the top and whole taproot, or roots, can be eased out of the ground. Place the roots on a hard surface, somewhere they cannot re-root, which they do readily once they can make contact with the soil.

Trees, shrubs and roses

Shrub roses and ramblers could now be pruned by removing some of the shoots that flowered. For areas due to be planted with trees this autumn, make sure all existing vegetation is completely killed before planting with two applications of glyphosate-based spray. Young trees and shrubs will continue to build reserves.

Flowers

Buy spring bulbs and plant them as soon as possible. A start can be made to dividing perennials, although it is still early, the soil being in ideal condition, and the plants often make good roots quickly. There is a last chance to take cuttings of tender plants, such as marguerites, fuchsias and African daisies, to carry over winter.

Fruit, veg and herbs

Do not let weeds go to seed now, to avoid building up trouble for the future. Raspberry and tayberry canes that have finished fruiting could be pruned out and the new canes tied into position. Finish off any remaining summer pruning of over-vigorous apples and pears, shortening the long whippy shoots to about finger length.

Lawn

There has been strong growth of grass in recent weeks, but some lawns have grown tired, as nutrients were leached out. Apply autumn lawn feed if the grass is pale. Prepare now for sowing new lawn areas, or resowing this month or next. Continue mowing regularly and rake off leaves as they fall, or chop them up with the mower.

Greenhouse & house plants

Pick grapes as soon as they are ready. Continue to remove unwanted flowers on tomatoes and allow only existing fruit to develop. Grey mould disease is a problem for many greenhouses and good hygiene is the best way to avoid it. Remove all debris and do not over-water or splash water.