Proper Care Keeps Roses Blooming

The free-flowing characteristics of roses that we now take for granted did not always exist. Work to produce repeat-flowering roses only began to receive attention in the early 1800's. It was not until the mid 1800's that the first hybrid tea and hybrid perpetual roses were developed. At that time the repeat blooming character was not as constant as in modern roses. Culture and climate greatly influenced the number of times a rose plant would flower during the summer. Even today, culture is important.

Roses are heavy feeders and a constant source of adequate fertilizer is necessary for good vigor and the accompanying flowering. As soon as the major flush of flowers has finished, a repeat fertilization, similar to the one given in early spring, should be applied. Generally, when a common garden fertilizer such as a 5-10-5 is used, about 1/4to 1/2cup may be applied per plant depending on the plant size and area to be covered. The fertilizer should be lightly scattered on the surface and scratched into the soil or mulch.

Even though rose plants may look quite lush at certain times of year, disease problems such as black spot may be beginning to develop near the base of the plant. The fungus disease causes spots on the leaves that then yellow and drop off. It is a serious rose disease and can weaken plants because they can not maintain enough foliage for good growth. Not only does black spot make plants look bad but it reduces flowering and makes them more subject to winter kill.

To keep black spot under control, regular fungicide applications are important, especially after wet periods. Among the materials, that provide good control are Triforine (Funginex), Folpet (Phaltan) or Benomyl (Benlate). In addition, spread can be reduced by picking off and destroying dropped leaves. Some roses have exhibited a mottled leaf yellowing this season. This may be an expression of a rose virus. Rose mosaic or rose yellow mosaic may be responsible.

Under certain environmental conditions the mottled yellowing of some leaves, or yellowing of the veins in other leaves, may appear. There is no known cure of these diseases once infection has occurred. It's generally felt that these two diseases don't do sufficient damage to make destruction of the plants necessary. A new disease which may be a virus sometimes occurs which causes deformation of new canes, extreme thorniness and greater red pigmentation in the shoots. When plants are seen with this type of deformed growth, they should be destroyed. The disease can be highly damaging and will spread to other plants: It has been found in wild multiflora rose in some locations.

Yellowing in rose leaves may not always be a virus problem. If the yellowing is particularly evident in young leaves it may be a problem called iron chlorosis. Although the cause is a lace of iron in the tissue, it is seldom due to a lack of iron in the soil, but to a damaged root system which is not able to absorb sufficient amounts of this element. It may appear during or after a season of extremely wet weather, when root growth has been limited. Good control of weeds as well as insect pests is also important to keep roses blooming. Mulch aids where watering is not possible, and keeps soil moisture more uniform even when plants are watered.

Source:

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