Caring for Trees and Shrubs in Mid Spring

Supporting

If you have not already got supports in place for some of the climbers, you should get them fixed early this season. Clematis will be growing very fast and may be halfway up a wall; in warm gardens eccremocarpus shoots may be long enough to start flowering. Panels of plastic-covered trellis, or horizontal wires spaced 30cm (i2in) apart, attached to wall nails, are amongst the strongest and most convenient supports for wall climbers.

If you have climbing roses, wisteria, Russian vine (Polygonum baldschuanicum) or honeysuckle scrambling over pergolas, archways or fences, make sure that they are stout enough to support what will eventually be a considerable weight of vegetation when dry, and half as much again when wet. Summer gales can be almost as fierce as winter gales and, once these climbing plants are blown down, their effect will never be the same again for the rest of the season. Repairing the damage is such a thankless and complicated job that it is tempting to cut everything off at ground level and be without any display until next year. So, if you make everything much stronger than you think it need be, you will be greatly relieved later on.

Protecting

New growth on any plant is vulnerable to cold but, at night, and even during the day, is still possible. Young shoots caught by frost will die back from the tip and can then be infected by fungus diseases, such as grey mould; this compounds the damage, and flowering though it is probably not practicable to growth, you will have favourite shrubs, plastic netting, newspapers or thin nylon) can be draped over them until the risk has passed.

Protective mulches which have been put over the crowns offender plants, such as fuchsias, eccremocarpus, romneya, solanum and cerarostigma, in late autumn, should be removed carefully, as the plants will have started to sprout at the beginning of this season.

Thinning

Apricots, peaches and nectarines, which are wall-grown, will have set their blossom by now in all but the coldest gardens; when the fruits are about the size of a marble, you can start thinning. Do it gradually over about two weeks until they begin to ‘stone’, the sign of which is that the fruit stops swelling. After this, they will have a small natural drop and you can then do a final thinning, if necessary.

Start by taking off fruit growing towards the wall, then take one away from every pair and eventually remove some of the remainder so that there are about 12 peaches to every sq m (sq yd) and 20 nectarines for the same area.

Apricots have a heavy natural drop and should not be thinned until after this, when they can be spaced in the same way as nectarines.

Increasing

There is still time to graft, as the bark will lift easily all the time the sap is rising, from early to late spring; if, however, the buds on the scion start to sprout, the scions will no longer take and the grafting cannot be done for another year. Another method of increase, used on ornamentals, is layering, and there are many shrubs, climbers and roses which can be easily propagated in this way. Choose a good shoot which grew last year and which is growing close to the ground; make a cut upwards on the underside, opposite a joint, through part of the stem. Pull the stem down to the soil so that the cut is in contact with it and peg the shoot down or hold it in place with a stone. The cut should be made several centimetres (inches) from the tip. When the layer is pegged down, the end of the shoot should be bent gently upward and tied to a cane.

If you layer the plants now, they should have rooted and be ready for lifting and planting in the autumn. .Many will root if layered any time between spring and autumn, but doing it now docs mean that they can be planted at one of the most suitable times. Plants to layer include rambling and climbing roses, rhododendrons, viburnums, magnolia, laurel, spotted laurel and various other evergreens. It is worth trying this method on any shrub with conveniently low-growing shoots; even if you do not want the rooted layers as new plants, they increase the visual effect of the parent plant so that it provides an even better show.

Layering shrubs: Choose a young shoot near to the ground, make a cut partially through it on the underside, wedge open, and pin down into good soil or compost.

Many woody plants can be grown from seed sown in spring, and mid-spring is probably the best period. It can be sown outdoors in a seed bed, where the soil has been dug in winter, and then raked to crumb-like consistency on the day of sowing. As seedlings have a particular need for the mineral nutrient phosphorus, superphosphate should be mixed in a week or so before, at 30g per sq m (1oz per sq yd). Seeds of the more tender species can be sown in cold frames using seed compost and seed pans or direct into the frame soil suitably prepared. Germination may take any time from a few days to a year.

Seeds of some plants need stratifying. Top-fruit stones and pips will germinate well but the resultant plant will not be the same variety as its parent. Moreover, seedlings tend to be very vigorous and either do not come into bearing at all or do so after ten years or more. Seedlings of ornamentals will also be different from their parents, and if you want exactly similar varieties or hybrids, you will have to use vegetative methods of increase: layering, cuttings, budding or division.

Weeding

From now until the end of autumn, weeding will be necessary at intervals, but it is not nearly such a problem as in the kitchen garden or where the herbaceous plants are grown. If you like clean rose-beds, there is a weedkiller which will keep the weeds at bay for the season, or you can use mulches. Ground-cover plants are another possible way of keeping down weeds, but it does mean trampling on them when pruning and feeding the roses can be awkward.

The same weedkiller can be used round certain shrubs, climbers, hedges and fruit, as the makers direct, but a better method is to mulch heavily. It does the plants a power of good as well. Of course, if you have specimen shrubs, trees and fruit growing in a lawn, or if you have an orchard down to grass, the weed problem can be ignored, if you like. Lawn weeds can be left alone, provided they do not overwhelm the grass, and an orchard mixture of grasses and clovers will effectively keep out other plants.

Grass cutting

Orchards down to grass should be cut now and kept at about 10cm (4in) until the end of mid-summer, when they can be left, though for convenience at fruit-picking time; the grass is probably better kept short.

Making a compost heap

Do not put prunings on the compost heap unless summer ones, of soft green shoots; those with bark or hard, tough tissue should be burnt. The resulting ash will be rich in potassium.

You can make the heap out of the orchard mowings, weeds, dead flowers, leaves (not evergreens, they are too tough to rot down well) and soft prunings. Build it with 23cm (9in) layers of vegetative material alternating with 5cm (2in) soil layers, up to 120-150cm (48-60in) high, enclose it with wood or polythene and cover when finished. It should be ready for use in autumn.

Ringing

Pear trees can be ringed at blossom time.

Treating pests and diseases

This is the season when greenfly and caterpillars will eat blossom as well. Vine weevils start eating holes in the edges of rhododendron leaves nearest the ground; slugs will attack the new shoots of fuchsias, hydrangeas, romneya and tree peonies. Rabbits may also attack these succulent shoots. Mildew may appear or continue to spread on roses, apples and pears, and infected shoots should be cut out. Scab on apples and pears may infect leaves and bad infections are likely to occur in warm, rainy springs. Rose black spot may appear or continue to spread. If peach-leaf curl on peaches, nectarines, almonds and apricots appears, pick off infected leaves and cut out infected growth as necessary; destroy all diseased prunings.

Young clematis may go off suddenly with clematis wilt; cut the shoots concerned down to ground level as soon as seen and cover the cut surfaces with a fungicidal wound-sealing compound. Spray new growth with a fungicide.

If you had grease-bands on the trunks of fruit trees, they can be removed now, as they will not be needed until late summer, when the adult winter moths begin to appear.

more on Shrub and Tree Garden Guide for Mid Spring …

30. August 2011 by admin
Categories: Trees and Shrubs | Tags: , , , | Comments Off on Caring for Trees and Shrubs in Mid Spring

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