If your soil does not happen to be ideal for fruit-growing, you can do something to improve it and you can choose for planting the fruits least likely to be adversely affected.
Drainage The first and most important point of all is drainage. All fruits need good drainage for waterlogged conditions in winter kill the roots by drowning.
Sometimes it is possible to lay field drains in the direction of the fall of the land or to dig trenches at least 30 in. deep, spread 9 in. of rubble in the bottom and cover with inverted turves before returning the soil. Unfortunately this procedure is seldom possible in gardens because there is no outfall without which no drain can function.
Deep digging, however, will improve surface drainage and this should be carried out over as much of the garden as possible. If you only prepare individual sites for the trees, these become miniature sumps collecting surface water from their immediate vicinity.
It is also possible to mitigate the effects of bad drainage by planting on mounds or raised beds.
Clay soil is, naturally, much more likely to collect water in winter than a light, sandy soil. To open up a clay soil, work in sandy or gritty material and vegetable matter such as well-rotted dung, peat, garden compost, spent hops, composted seaweed or leafmould. These same materials that will open a heavy soil will give ‘body’ to a very light soil.
As a general rule when preparing for fruit a piece of previously cultivated garden it will be quite unnecessary to add any manure. Over-rich soil will only encourage lush growth at the expense of fruiting. Soft fruits require a rather richer soil initially than the tree fruits and a soil containing plenty of vegetable matter which retains moisture well in the summer is invaluable.
Whether you are preparing a previously cultivated site or a piece of virgin meadowland, it is important to eradicate all perennial weeds. These can be a considerable nuisance in a fruit plot later and not easy to deal with when their roots are intertwined with those of the fruit. Where severely weed-ridden areas are concerned, it may be advisable to defer planting for a year to devote a whole growing season to fallowing the land and eliminating every weed to appear. Annual weeds can be easily dealt with by the application of a contact weedkiller. A total weedkiller such as sodium chlorate (dose: 2 oz. per sq. yd.), will make short work of all weeds but it will render the soil sterile for as long as a year, during which time it would be unsafe to plant anything.
The degree of acidity of the soil is of much importance to the fruit-grower. All the fruits we grow, but two, flourish best in a slightly acid soil. The two exceptions are blueberries and cranberries which like very acid conditions.
Because chalk is alkaline, chalk-land areas are not noted for fruit-growing. Nevertheless one often sees quite flourishing garden fruit trees and bushes in these districts-it all depends on the depth of slightly acid soil lying on top of the chalk. Provided no deep digging is practised, to stir up the chalk lumps and bring them near the surface, the natural action of rain and drainage wash the alkaline chalk particles downwards rather than up. Some fruits will tolerate a certain degree of chalkiness better than others.
When preparing ground for fruit it is prudent to test it for acidity or otherwise. Testing outfits for garden use are quite inexpensive. Make several tests, using distilled and not tap water, and average the results.
One cannot in the garden control acidity within fine limits, nor is it necessary. Ideally we should like the test to show a pH scale reading between 6.0 and 6.5. But if the test shows a reading under 5.5 spread a 3 oz. per sq. yd. Dressing of hydrated lime over the surface and lightly prick it into the topsoil. (The pH scale indicates the acidity or alkalinity of the soil. PH To indicates neutrality, readings below this indicate the degree of acidity, those above 7.0 indicate the degree of alkalinity. The scale is logarithmic, i.e. a reading of pH 5 shows that the soil is to times as acid as a soil which has a reading of pH 6 and one which has a reading of pH 4 is too times as acid as a soil with a pH 6 reading.)
It is not so easy to rectify matters if the test shows an alkaline reaction (over 7.0 pH scale). If the alkalinity is the result of over-liming in the past (old vegetable plots often suffer in this way), then of course you should not add any more lime. The addition of any humus-making material-farmyard or stable manure, garden compost or peat- will all help to reduce the alakalinity. Refrain from using old mushroom compost manure because this usually contains chalk and is slightly alkaline. In future years fertilizers of an acid nature (e.g. sulphate of ammonia) should be preferred for the provision of nitrogen.
The reason why an alkaline soil is unfavourable for fruit-growing is that in such conditions certain trace elements-quite essential but required in tiny amounts only-become chemically unavailable to the roots. The minerals chiefly concerned are iron and manganese and in chalky land fruit trees and bushes soon begin to show the deficiency symptoms of loss of leaf colour between the leaf-veins and die-back.
Simply feeding extra iron and manganese is no remedy because the ordinary fertilizers soon become locked up, too. Chemists have circumvented this by producing these minerals in a form known as chelated or sequestered and one can now buy fertilizer mixtures containing both chelated iron and manganese for application as a liquid from the watering can or as a foliage spray. The use of chelated fertilizers has made fruit thrive in gardens where it has never flourished before.
Soil preparation should be completed several weeks before planting so that the disturbed ground can settle properly. Early digging is important where manure has to be worked in (no manure should ever come into contact with the roots at planting time). Shuffling your feet over the dug soil will break up surface lumps and help to settle it.