There are a number of decisions of a design nature that determine whether or not your roses will look good. There are also special seasonal tasks, such as pruning, that are essential for success. But sandwiched between the two, are the basic cultural requirements that have to be met in order to get the most from the rose bushes. These requirements could be termed the preconditions for success.
Choosing the right location.
Roses require exposure to at least six hours of direct sunlight in hot Mediterranean climates, mostly in the morning. In regions with less light intensity, they probably need more. Roses should not be planted under trees, not only because of the shade, but also because they compete poorly with the trees' roots. For the same reason, they should not be planted too close to shrubs either.
While roses can thrive in hot, dry climates, they suffer in warm, humid ones. Gardeners can unintentionally create excessive humidity, by planting the bushes where there is insufficient movement of air, or by placing the plants too close to each other. Whatever the cause, humid conditions are ideal breeding grounds for fungi that plague roses, such as powdery mildew. It is important therefore to know the width of the plants' growth, and to fix the distance between the roses, accordingly. Do not be tempted to over-plant.
Soil conditions
To grow well and flower profusely, roses need highly porous soil. If the earth is clumpy and hard, it must be broken up and improved with massive quantities of compost. In either very heavy, clay soil, or alternatively, extremely light, sandy soil, some 60 liters per square meter, is by no means excessive. In medium, loamy soils on the other hand, about 20 liters should suffice.
While many wild species of rose are of Mediterranean origin and even harsher Central Asian climates, the cultivated varieties that make up the bulk of garden specimens are not especially drought resistant. In areas without summer rain, it is essential to supply them with regular water. Unquestionably, drip irrigation is preferable to overhead sprinklers, because not only do the latter waste more water, but they add 100% humidity into the bargain! Never forget that an improper watering regime is liable to deplete the soil of oxygen; a condition to which roses are particularly sensitive.
Mulching the soil
Covering the soil with an organic mulch helps to reduce water loss, retard weeds, and perhaps most crucially in hot climates, moderate the temperature at the topsoil level. In my view, mulching with an aesthetically pleasing material like wood chippings is preferable, design wise, to under planting the rose bushes with flowers. While in cultural terms, infinitely improved growing conditions are attained, without the roses having to contend with any competition from rival plants.
About the Author
My name is Jonathan Ya'akobi. I've been gardening in a professional capacity since 1984. I am the former head gardener of the Jerusalem Botanical Garden, but now concentrate on building gardens for private home owners. I also teach horticulture to students on training courses. I'd love to help you get the very best from your garden, so you're welcome to visit me on http://www.dryclimategardening.com or contact me at jonathan@dryclimategardening.com
