My "Red Masterpiece" tea rose leaves are turning brown at the tips, then are curling up! Never have seen this before on any of my roses! So, far this season, this rose has not produced one bud!
Salt Burn
Symptoms include the edges of the leaves turning brown.
This common problem is caused by a buildup of salts in the
soil and subsequently in the plant tissue. Salts can accumulate
from inefficient watering practices or if an excessive amount
of fertilizer is used. Symptoms typically are the browning of
leaf margins of browning of the entire leaf (Fig. 7). Avoid this
problem by periodically watering slowly and deeply to leach
3The University of Arizona Cooperative Extension
Sulfur or fungicides can be applied to the foliage as a
preventative or to treat powdery mildew. To avoid burning
the foliage, do not use sulfur when the temperatures exceed
90 degrees F.
Rosarians who exhibit in shows usually begin their
management program before powdery mildew appears
because it is difficult, if not impossible, to eradicate once
it becomes established. They spray with a fungicide
immediately after pruning in January or February.
Fungicides work better as a preventive measure early in the
season before the mildew takes hold. As with any product,
follow the instructions exactly. It is also a good idea to test
a few leaves first before spraying the entire plant.
Crown Gall (Agrobacterium tumefaciens)
Due to stringent screening by many rose growers,
crown gall is not commonly found in rose plantings. This
destructive disease causes a warty looking gall at the base
of the canes that can vary from the size of a pea to the size
of a fist. (Fig. 6). Gall development causes gradual plant
decline. The bacteria may arrive on contaminated nursery
stock and once introduced, the bacteria persist in the soil
for several years. Infection takes place through wounds.
To prevent the disease, examine plants for galls carefully
prior to purchase and prevent injuries during transplanting.
There is no treatment. Remove and destroy infected plants.
Do not replant roses, pyracantha or stone fruits in a place
where crown gall is present.
Other Problems
Salt Burn
Symptoms include the edges of the leaves turning brown.
This common problem is caused by a buildup of salts in the
soil and subsequently in the plant tissue. Salts can accumulate
from inefficient watering practices or if an excessive amount
of fertilizer is used. Symptoms typically are the browning of
leaf margins of browning of the entire leaf (Fig. 7). Avoid this
problem by periodically watering slowly and deeply to leach
salts past the root zone. Also, carefully follow the instructions
on fertilizer containers and do not over apply. ("If a little bit
is good, then a lot must be better", does not hold true for
fertilizer!) By applying the fertilizer in a 'split application', i.e.
applying half the recommended amount in two applications
timed about 2 weeks apart will minimize the potential for
fertilizer 'burn'. Water thoroughly before and after fertilizing
to help prevent burn
