News & Updates:

Die-back in roses has never been recorded authoritatively in Australia as a distinct infectious disease. Overseas it has been described as a fungus disease due to Gnomonia rubi. So far, in this country it is always merely a terminal symptomatic phase and secondary to some other factor. The most common forms are:

1. Constitutional die-back, such as in Pernetianas and Wichuraianas. In the former, almost every year, part of the plant dies but strong new branches grow. It is not infectious, is unavoidable, and varies in degree with soil and atmospheric conditions. In most Wichuraianas nearly all of the preceding year's wood dies.

2. Die-back that is secondary to defoliation caused by heat, drought, spray-burn or black spot.

3. Die-back as the terminal phase of rose wilt.

4. Die-back during winter or early spring due to the effects of cold conditions on immature wood.

5. Die-back due to deficiency of one or more plant foods, especially potassium, nitrogen, calcium, phosphorus, copper, boron, and zinc.

6. Die-back due to senility, injury, inefficient drainage, canker, sunburn, and other minor causes.

It is useless to attempt to treat the symptom, die-back; one must discover the cause, and then adopt appropriate measures.