Roses, ideally like a deep, good quality loam, not waterlogged or sour, but well supplied with plant foods and stiff enough to allow the roots to find a congenial cool run. Yet many successful rose growers have to produce their plants and blooms under quite contrary conditions to these. They have had to make the most of what they possessed and their success should be an encouragement for anyone who feels he has little chance of excelling because his garden is not composed of just the sort of soil which he has been given to understand is essential.
With good cultivation and the proper manure, almost any garden may be made to produce satisfactory roses. Roses do not liked to be dried out, yet they appreciate enough sun to ensure thorough ripening of the wood. The more open the beds are to light and air, the better. If the soil is naturally light and quick draining it must have sufficient organic matter added to ensure that during a dry spell it will not become parched. Organic matter is equally useful on clay soils to improve their texture and prevent them cracking in hot weather.
While partly rotted organic materials provide the basis of nearly all natural plant food taken up by the roots, they also act as a sponge, holding on to soil moisture which would otherwise be lost. At the same time soil texture is improved enormously by the air spaces left as the material breaks down further into humus and it is from this that clay soils particularly benefit.
Humus itself is the end product of the complex breaking down of organic materials added to the soil. It takes some time to reach this state which is why you provide regular dressings of organic matter to your roses.
Humus can be provided in a variety of ways where the most well known variety is well rotted farmyard or stable manure. Other varieties are decayed vegetable matter and lawn mowing and other garden refuse, stacked for a few months and turned occasionally.