Weather and the Gardener
Although good weather and skilful gardening will encourage plant growth, there are other things which prosper under favourable conditions and are less welcome in the garden, namely, pests and diseases.
The weather is the controlling factor which determines the rapid increase of a pest or disease. Warm, dry weather seems to favour the prevalance of garden pests, although it can also accelerate the mulitplication of their natural predators.
Wet and humid weather is more favourable to most diseases such as potato blight, and July is the month when spraying against blight is most important, especially f outdor tomatoes are being grown nearby, as they are also subject to this disease.
Notice should be taken of the weather forecasts when selecting the time to spray, because it is no use applying a dust or spray to plant leaves if it is going to be washed off quickly by rain. Rain, however, can help to wash in a top dressing of fertilizer or other surface treatment.
Trees and Shrubs
Some trees, shrubs and climbers giving a good display in the month of July include forms of catalpa (Idian bean tree), magnolia, liriodendron (tulip tree), Buddleia davidii (butterfly bush), calluna, baboecia and erica (heaths and heathers), cistus (rock rose), escallonia, fuchsia, hebe, hydrangea, hypericum (St John's wort), lavandula (lavender), olearia (daisy bush), philadelphus (mock orange), potentilla (cinquefoil), rhododendron, yucca, clematis, jasminum (jasmine), lonicera (honeysuckle), passiflora (passion flower) and polygonum (Russian vine).
Pruning
Continue lightly pruning those plants which flower on the current year's growth, such as jasminum (jasmine), philadelphus (mock orange), deutzia, cytisus (broom), helianthemum (rock rose) and Choisya ternata (Mexican orange blossom).
Hedge Pruning
Trim to shape any hedges that require attention, either using shears for formal hedges or secateurs for informal ones. Hedging plants usually requiring treatment now include berberis (barberry), cotoneaster, pyracantha (firethorn), rosmarinus (rosemary), hebe, fagus (beech), ilex (holly), Carpinus betulus (hornbeam), taxus (yew), ligustrum (privet), buxus (box), evergreen ceanothus, deutzia, laurus (laurel), Crataegus monogyna (quickthorn), Chaenomeles japonica (Japanese quince) and Osmanthus delevayi. Burn all prunings.
Flowers
Divide overgrown and weakly clumps of bearded irises, Iris germanica, and replant in well-dug soil enriched with 130g per sq metre (4ox per sq yard) of balanced fertilizer.
Watch out for twisted, curled and needle-like leaves on phlox which indicate an attack by eelworm, a pest which is microscopic and which lives only in the stems, never invading the roots. Wait until autumn, then dig up and burn infested plants and perpetuate your stock from root cuttings.
Scatter a high-potash fertilizer over the root areas of plants such as salvias and solidago which are beginning to bloom. This will accentuate the flower colour and increase the plants' resistance to pests and diseases.
Disbud early chrysanthemums, removing all but the terminal bud on each stem if you want large, show-quality blooms in autumn. Go over the plants several times each season.
Save seed pods for earlier flowered aquilegias, lupins, oriental poppies and some other plants that set viable seeds freely which can be gathered now and sown immediately to raise new plants. Germinate them in shallow drills 15cm (6in) apart in a hummus-rich patch of ground in full sun.
Alpines
Take cuttings of dianthus; pull out growing tips (called pipings) and insert in pots or trays of sandy compost in a cold frame shaded from bright sunlight. Water with a rised can to keep the soil just moist but not soggy.
Keep up a war on weeds, pricking over the soil with a long-handled 'hand fork'. This is a most useful tool, allowing you to probe far back into the rock garden without treading on and damaging plants.
Bulbs
Plant Amaryllis belladonna, a spectacular late summer/autumn flowering trumpt 'lily'. Set the bulbs with their bases 15-20cm (6-8in) deep and resting on a 2.5cm (1in) layer of sharp sand if the soil is heavy and inclined to lie wet after heavy rain. Groups of six or eight bulbs will provide a breathtaking spectacle when few other bulbs are in flower.
Cyclamen coum, C. europaeum and C. neopolitanum may also be planted. Set corms about 5cm (2in) deep in peat-enriched soil. Plant in groups of seven or nine for good effect.
Vegetables
A sowing of lettuce will provide heads in the autumn, and turnips sown early in the month of July will give storeable roots in the autumn given good growing conditions. Carrot and beetroot can be sown up until about the middle of the month in the south to mature before the winter, usually on land cleared of earlier crops. Make a further sowing of parsely for use in the spring.
In northern gardens, seeds of spring cabbage should be sown at the end of July for transplanting in September. If, for any reason, the garden looks as if it is going to be short of brassicas in the winter, sow spring cabbage in situ in the second half of July.
Planting Brassicas
Plant out, from seed beds, brassicas required for winter cropping - winter-hardy cauliflower, winter-hardy cabbage, kale, sprouting broccoloi and savoy. This is often a difficult time to get plants established because temperatures are high and it is dry. Transplant in the evening rather than the morning, plant firmly, having scraped aside dry surface soil to expose the moist soil 5-8cm (2-3in) down. Water plants thoroughly.
Runner Beans
Runner beans should be growing towards the tops of their supports and when they have reached them, the growing points should be pinched out. There is no point leaving them to grown on as a means of producing a late crop. Plants stop cropping because beans are left to mature instead of being picked regularly.