Planting and maintenance of shrubs and climbers

Planting time for shrubs always used to be spring or autumn for evergreens and anytime when dormant for deciduous varieties. Now that most kinds are available as container-grown plants, do these restrictions still apply?

Container-grown shrubs can be planted at any time of the year, but the fact remains that those planted at the traditional planting times will need the least attention. If you plant in summer, for instance, you must pay particular attention to watering, for if the rootball—which is usually of peat compost—is allowed to dry out, it will be very difficult to wet it again thoroughly; it will tend to drain very rapidly, and the plant will suffer.

I am planting up a large area with shrubs this winter. Should I plant them closer than is really necessary and so get good effect fairly soon, or should I plant at final spacings?

The problem with planting fairly close with the idea of thinning out later is that, when thinning becomes necessary, it may be difficult to bring yourself to do it! Rooting out thriving plants is not easy and you may find that those which remain have become spindly as a result of having to compete for light.

I suggest that, provided you buy good-quality plants, you plant them at their final spacings and fill the gaps with ground-cover plants. The latter will keep down the weeds, look attractive, and not impede the growth of the shrubs. Annuals and bedding plants are cheap infilling alternatives.

I sent off for some shrubs last winter, but when they arrived the ground was frozen. I was not sure what to do with them. Could you advise me?

Most shrubs and climbers, and especially deciduous ones which are sent out by mail order, are despatched with bare roots, not in containers. If they dry out they will die. When they arrive, and if there is no soil at all on the roots, stand them in a bucket of water for a day or two in a cool but frost-free place until the soil is in a fit state to receive them. Alternatively, store them for longer periods with their roots in moist peat.

Those that arrive with some soil on the roots, probably wrapped in netting, are best watered carefully with a can fitted with a fine rose, and stored in moist peat. As soon as possible after their arrival, dig a trench in a vacant bed of soil, lay in their roots, and replace the earth. lHealed-in’ like this the shrubs will stay in good condition for many weeks until the planting site is frost-free fully prepared, and in good condition.

We are recommended to use farmyard manure when planting shrubs, but I cannot get it locally. What is the best alternative?

Good farmyard manure, well-rotted, is probably the best organic material to use to improve soil structure and encourage the development of humus ; but there is a number of more easily available alternatives and I suggest you use whichever of these is easiest to obtain.

Garden compost is easy to make, and a couple of home-made bins will produce a continuous supply. The contents of used growing bags are worth having, and you can sometimes get this material in bulk from commercial tomato growers. Spent mushroom compost, which usually contains at least some stable manure, is very good, although it contains chalk and may have an undesirable effect on lime-hating plants. There is also peat; but if you use it you should add two or three handfuls of bonemeal or Growmore fertiliser to each bucketful. Lastly, there are the proprietary brands of bulky organics; although they are mostly good, they are rather expensive.

I would like to train some climbers on the wall of my house but do not want to use too many nails. What is the best way to go about it?

There are two good ways. For small areas you can put up trellis; for larger areas it is better to put up a permanent wire-support system. Trellis can be attached to the wall with screws and plastic plugs after you have drilled holes with a masonry drill. To support wires, plug the wall and screw large vine eyes into the brickwork 1-1.2 m (3-4 ft) apart and at vertical intervals of 450-600 mm (18-24 in). Plastic-covered wires can then be threaded through the vine eyes and tensioned by means of eye bolts at one end.

To get some extra height in my borders I want to grow some clematis or climbing roses. What is the best way to support them?

Rustic poles make the most unobtrusive supports. They should be about 3 m (10 ft) tall and must be hammered at least 450 mm (18 in), and preferably 600 mm (24 in), into the ground Paint them with a good wood preservative (not creosote) first. A few cross-pieces will help support the plants that can be trained along them. Clematis can be supported on tubes of special clematis netting: 2 m (6 ½ ft) lengths of netting are nailed to 2.4 m (8 ft) stakes, which are hammered 600 mm (2 ft) into the ground. This support is really suitable only for those late-summer-flowering varieties which can be cut back in spring to keep them to a reasonable size.

A wound has appeared at the base of a shrub in my border and it refuses to heal. What can I do about it?

It sounds as if the base of the stem has been damaged in some way, probably by hoeing. Take care when working through the border not to hit stems. The wound can be repaired by cutting away any rough parts with a sharp knife and painting the wound with a proprietary wound paint.

How can I protect my lobster-claw (Clianthus) and mimosa (Acacia dealbata) from frost in the winter?

The simplest way to protect shrubs in general is to attach netting to the wall above the plants and then to roll it down and fix it to the soil in front of the plants whenever frost threatens. This will provide a surprising amount of protection— but remember to remove it on warmer days.

Are there any particular problems involved in planting a climber to run up into a tree?

There are a number of important points. Pick a self-clinging variety—one with thorns, tendrils, or suckers—or a twiner. Plant the climber about 1 m (3lA ft) away from the trunk so that the tree does not take all the moisture from the shrub’s soil. Prepare the soil well with plenty of organic matter, and provide supports to lead the shoots into the tree. It may be necessary to tie a stake to a branch to keep it secure. See also 269.

A branch on my birch tree has broken in a gale, but it is still partly attached to the tree. What should I do?

Generally speaking, trying to repair a broken branch is not a good idea. The break is usually so ragged that the fibres could never be fitted together again and the wound will never heal properly. It is usually far safer to remove the branch cleanly, and paint with a bituminous wound dressing .

What can I do to help my hardy fuchsias to over-winter successfully?

In the coldest areas you have no option but to take cuttings and overwinter the plants in a greenhouse or conservatory. In warmer areas you can help them survive by not cutting the stems down in autumn, by making some holes around each plant with the tines of a fork to help water drain away, and by piling leaf mould, ashes, or soil around the base of the plant to protect it. Some varieties, incidentally, are hardier than others, the toughest being Fuchsia magellanica, F. ‘Riccartonii’, and F. ‘Mrs Popple’.

I planted a camellia a few years ago and it has done very well. Unfortunately, when I build my house extension the camellia will be in the way. Can I move it, and if so how should I go about it?

Camellias and other fibrous-rooted evergreens such as rhododendrons can be moved quite safely, at the right time of year—in September-October or April-May. If you have plenty of warning (say, six months) of the need to move, cut a circle around the plant by slitting the soil vertically with your spade. For a plant up to 1.2 m (4 ft) high, the cut should be about 300 mm (12 in) from the stem; for plants taller than 1.8 m (6 ft) it should be about 600 mm (24 in) from the stem. The slit, which should be to the depth of the spade blade, will cut some outer roots and encourage others to grow nearer the centre of the rootball.

Prepare the new site with plenty of organic matter, such as peat, and then, immediately before moving, thin out the shoots a little to compensate for the unavoidable root loss. Lift the shrub gently, keeping as much soil as possible on the roots (wrap them in polythene if necessary). Plant it carefully, replace the soil, water it in well, and stake it unless it is in a very sheltered spot; if the site is especially windy, put up a plastic wind-break. Keep a vigilant eye on the soil, watering it as necessary.

We are always recommended to dead-head flowers and house-plants. Should shrubs also be dead-headed?

Ideally, shrubs and climbers should be dead-headed, too, except those grown for their fruits; but the fact is that with most shrubs it is not practicable. It is, however, definitely worth doing with buddleias as it prolongs their flowering season; and it is always recommended for rhododendrons, although on all but the smallest specimens it is a long, fiddly job. Hydrangeas should also be deadheaded—but not until spring, as the old flowers help to protect the following year’s flower buds.

I think that I ought to be feeding my shrubs to get the best out of them, but I am not sure exactly what I should do. Can you advise me?

The best way to feed shrubs once they have been planted out is to mulch them with a layer of organic matter spread around the base of the stem, usually in spring when the soil is moist .

Leaf mould or well-rotted weed-free compost is a suitable material; but the simplest way to go about mulching is to rake all the fallen leaves on to the border in autumn and let them rot down. This also helps keep the soil moist. However, bacteria use up a lot of soil nitrogen when they rot down the leaves; so to make sure that this nutrient is not in short supply, scatter a handful of sulphate of ammonia over each square metre (square yard) of soil in spring.

I have a large lawn. Can I spread my lawn-mowings as a mulch under shrubs?

There is a problem with using lawn-mowings. Most lawns contain weeds and weed grasses, particularly annual meadow grass, and if mowings containing the seeds of these unwanted plants are spread on the border, it will soon be full of weeds as well. It is better to compost the mowings, either on their own with a special activator or mixed sparingly with other material in the compost heap.

In my small city courtyard I have a number of shrubs and climbers in tubs and urns. My problem is that they seem to dry out very quickly. What can I do about it?

Some types of container dry out more quickly than others. Terracotta and concrete containers lose water through the sides and so need watering more frequently than others. Wooden containers are better in this respect, especially if painted, while plastic glass-fibre containers lose none. The best thing to do is rig up a semi-automatic watering system using a narrow-bore plastic pipe connected to a water tap. Nozzles are fitted to the pipe at intervals so that when the tap is turned on water trickles out into each pot.

I grow a number of shrubs and climbers in pots. How and when should I feed them?

In the growing season feed them every two weeks with a balanced liquid fertiliser, or use a proportionately weaker feed every time you water them. If you have a semi-automatic watering system for them, you can buy a diluter that will automatically put feed into the water supply.

Can you explain how to prune flowering shrubs?

There are two basic groups of flowering shrubs. One group flowers in summer and autumn on the tips of shoots that grew earlier the same season. The group includes buddleias, large-flowered and cluster-flowered roses, caryopteris, St John’s wort (Hypericum), and some clematis hybrids. These must be pruned hard back in spring as growth is beginning, so as to encourage development of strong new shoots.

The second group includes plants that flower in spring on shoots which grew the previous season. This group includes mock orange (Philadelphus), forsythias, flowering currants (Ribes), weigelas, and beauty bush (Kolkwitzia). It is less vital to prune these; it is done immediately the flowers are over, and it involves removing the branches that carried the flowers. Shoots that will flower the following spring will already be growing and must be left unpruned.

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