Preparing the Soil for Growing Roses
Preparing the Soil
Most amateur gardeners have to accept their garden as it stands in relation to the house; but within these limitations it is certainly worth considering the particular requirements of. A look at the gardens of neighbouring rose growers is usually very helpful. Most gardeners are willing to talk about their successes — some even about their failures. The latter information, especially if it can be related to local conditions, can be very valuable if you are in your early days as a rose grower.
Roses generally succeed best in open, sunny positions, as long as they have some protection from cold winds from the north or east. If large trees or hedges are used as protection, make sure they are at a sufficient distance to ensure that they do not impoverish the, dry it out, or overshade it. Indeed, soil that has been well prepared for roses will itself encourage tree or hedge roots to spread unless a barrier such as corrugated iron or asbestos sheeting is used. You should therefore think carefully before planting trees or vigorous shrubs near your roses. In particular, trees such as weeping willows and poplars should be kept as far as possible from rose beds.
Climatic conditions must also be considered; areas of high rainfall will limit the choice of varieties, and adequatemust be ensured. In such areas the large, full-petalled roses usually favoured by exhibitors will be disappointing and so should be avoided. Most roses intended for display are grown in beds or borders cut out of a lawn. The site must be well prepared manually or mechanically and good drainage must be ensured, or results will be disappointing. Generally this can be achieved by thoroughly breaking up the subsoil over the whole area, thus avoiding the creation of a sump where a bed has been made on heavy soil and no drainage outlet is available. If your garden is on heavy land and a local ditch or a drain is available nearby, laying field drainpipes to it will help, especially if you cover the pipes with gravel or other porous material.
In the absence of an outfall, a soak-away at the lowest part of the garden is a suitable alternative. Dig a large hole 1 m (3 ft) in diameter and about twice as deep, replacing the subsoil with broken bricks or hardcore. Cover with turves or brushwood to within about 450 mm (18 in) of the surface, and then fill up with soil. Such a soak-away should be capable of dealing with surface water. These days, and most notably in south-eastern England, so much new building has taken place that drainage, especially in the summer months, has become more than adequate for plant life. Given proper drainage, what really matters is the top spit – 300 mm (1 ft) – of soil, in which most of the fibrous feeding roots of roses will remain when conditions are to their liking.
It has been customary to advocate deep cultivation for roses. Within reason, this is sound advice, especially if you remember the cardinal principle of keeping the fertile top spit on top and the subsoil below. By all means improve the subsoil by turning it over, breaking it up, and incorporating any organic material you can spare. This is, of course, hard work unless you are young and fit. Personally, having reached an age when I no longer indulge in unnecessary hard work, I confine my efforts to a depth of 600 mm (2 ft) – and then only because my roses are usually planted to remain in the same position for at least 12 years and possibly longer, depending on the variety.
Preparation of the bed by double digging is a simple operation, especially if it is square or rectangular in shape and large enough to enable it to be split into two halves. Remove one spit of soil 400 mm (18 in) wide and 250 mm (10 in) deep from one half and place it at the same end behind the other half. Loose soil can also be cleared. Now dig up the subsoil, using a fork if it is heavy clay. In the case of clay take the opportunity to fork in gypsum at the rate already mentioned. This not only renders the clay more porous, thus improving drainage, but helps to liberate nutrients which will benefit the roses. Gypsum should not be used, however, in well-drained soils.
The next strip of soil can now be turned over on top of the first forked-up strip of subsoil, incorporating with it any organic humus-forming material such as peat, leaf-mould, or farmyard manure. If grass turves have been lifted from a new garden or bed, these should be chopped up and placed on the forked-up lower spit. An organic fertilizer, such as bone meal or hoof-and-horn meal, should also be forked in generously, if you can afford the considerable expense. Peat can be applied to a thickness of 100 mm (4 in). Use the loose soil in the second trench for levelling up the surface of the first strip, and proceed with the work. The last open trench will be filled by the soil removed at the beginning. Do not be alarmed that the level of the bed is higher than before; it will soon settle, especially if a few rainstorms occur. This preparatory work is best done in early autumn, to allow some consolidation of the soil before planting takes place. I hope you will not regard all this work as being too laborious. Remember it is only before planting that such an opportunity occurs and, as you enjoy your roses over many years, you will come to regard it as time and effort well spent.
Deep cultivation by digging on light sandy soil is not really advisable, especially if the subsoil is also sandy, because digging will further increase the drainage and so will reduce the moisture content to unacceptable levels in summer. Rather than disturb the subsoil, concentrate your efforts on making the top spit more water-retentive by adding manure, chopped turf, heavy topsoil, or any other humus-forming material. A heavy dressing of bone-meal and/or hoof-and-horn meal will help to repair the shortage of nutrients. A generous mulch of peat or compost after planting will help to conserve moisture. On light soils it is also advantageous to keep the finished surface of the bed somewhat lower than the surrounding area, especially if irrigation in summer is required, as this ensures the rose receive the full benefit.
While this preparatory work is going on it is a good idea to have a few sacks or a polythene sheet to protect the surrounding grass and minimize clearing up. The same sheet can be used later to protect the bed from frost or heavy rain before planting.