Ground Preparation

Soil Texture
Soil Testing
Soil pH

Soil Texture
The ideal soil for roses is a sandy loam soil. This texture will allow your bed to drain well, yet retain the valuable nutrients your roses need. This characteristic will also be important to reduce the chances of disease in your plants.

When trying to determine what type soil you have, note that soil consists of three main particles; sand, silt, and clay. Sand particles are the largest of the three, clay particles the smallest, and silt falls somewhere in between the other two. The arrangement of, or percent combination of the three types are normally referred to as soil structure.

If your soil is very sandy it will not hold water well, therefore, the nutrients will leach out quicker. One positive effect of sandy soil is that it drains well and provides good aeration which will promote good root growth. Sandy soil is helpful in combating soil disease that is associated with poor drainage.

Unlike sandy soils, clay soils will hold water. This is a poor quality for roses. Clay soils are good in that they will retain nutrients, however, the moisture and poor aeration are not desirable for rose beds.

Silt, or a sandy loam soil is a happy medium between the two previous soil types. The structure of this type soil gives the best of both worlds. Sandy loam soil will allow for the drainage and aeration the rose roots need to combat disease and the nutrient holding capacity of the clay soils. The ideal structure for roses would be a mixture of 30 to 50 % sand and 30 to 40% silt, with 10 to 25% clay. Usually a good structured loam soil will be loose and friable. When mashed in your hand it will compact together yet fall apart easily. This type soil structure is not usually naturally occurring. Mst flower bed have to have some sandy or clay soil added to obtain the perfect soil structure.

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Soil Testing
Like animals, plants need to eat and drink. When people maintain a balanced diet they are healthier and feel better. Like people roses will take substantially less care when they are on a balanced diet. This begins with the nutrients in the soil. In order to determine what nutrients are in the soil a soil test should be done.

It is a good idea to get a soil test done every two years or so. This test will let you know what type nutrients are in the soil. Soil test kits are available from local garden supply houses that will help in revealing the pH of your soil, however to determine the nutrient value a laboratory test may be needed. Most county extension services will send your soil for a test that will come back with recommendations for your soil. This test will also let you know the texture, the amount of organic matter, the level of plant toxins, if any.

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Soil pH
The pH shows if the soil is acid or alkaline. The only way to determine the pH is by doing a soil test. Correct pH is very important in roses. Very high pH will result in yellowing leaves, stunted growth, and in some cases reduced plant life. The pH of soil is shown on a scale of 0 to 14 . A pH of 7 is neutral. Soils that get a lot of rainfall usually have acid soil between 4.5 to 7 pH. Soils in arid regions tend to have alkaline soils in the 7.0 to 8.0 range. In soils that have too acid or too alkaline cause nutrients to become insoluble and cannot be absorbed by the roots. At the same time toxic elements are more soluble and could damage the roots.

The ideal pH for roses is 6.0 to 6.5. In this range most of the nutrients needed for roses are readily available. Roses will tolerate a pH as low as 5.5 and as high as 7.5 but they will not grow as well as they would in the proper range.

If a soil test reveals that the pH is too low, you can raise it by adding limestone. Lime is a powdery material sold in most garden centers and agricultural supply stores. Apply the lime to the top of the soil and water it in. The pH should be corrected before the roses are planted. Using the results of your soil sample determine how much the pH needs to be raised. A good rule of thumb is to use 5 to 6 pounds of lime per 1000 square feet to raise the pH 1 full point, therefore, 2½ to 3 Lbs of agricultural lime would raise a pH of 6.0 to 6.5.

To correct for an alkaline soil condition you can lower pH by adding agricultural sulfur. It is also sold in powder form. Like limestone, it can be spread over the top of the bed and wet in. To reduce the pH of soil 1 point use 1½ to 2 lbs per 1000 square feet. Alkaline soil is harder to correct. Adding organic matter will make the soil more coarse allowing better drainage and aeration. Gypsum, or calcium sulfate, is an inorganic compound often used in soils with a high sodium content to improve the structure of heavy clay that does not drain well. Gypsum will break up the sticky clay to allow air and water to penetrate more efficiently. Sand, perlite, or vermiculite can also be mixed into the soil to improve the structure of an alkaline soil.

Rose beds should have good drainage. When the soil drains too slow, the water will take the place of oxygen that is vital for root growth. To test the drainage dig a hole about a foot deep, fill it with water and let drain for 1 hour. If there is any water left after an hour the soil may need some gypsum or other amendments to allow quicker drainage.

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