“What happened to my roses?” Q&A with Chalet’s Jennifer Brennan
Jennifer Brennan of Chalet answers some questions from gardeners on ABC 7 Morning News, June 30, 2009.
“What happened to my roses? The leaves look like tan colored pieces of paper that are ’see through’.”
The culprit: a rose slug, actually the larva of a small sawfly, which scrapes the cells off the back of the leaves. The good news is this will only happen once a year, the bad news is the eggs will drop to the ground under the rose and will happen the following year. Spray the plant with a systemic insecticide (Bayer Rose & Flower Systemic Insect Killer), so when the eggs get laid, the newly hatched larva will be killed.
“My plants were looking so happy and healthy during this cool spring, then 2-3 weeks ago the leaves started turning yellow and the plant just stopped growing. What is wrong and can they be saved?”
Spring ‘09 has been one of the wettest. When rain saturates the soil so frequently, all the air and Oxygen gets pushed out of the root zone, drowning them. Leaves need all the essential “building blocks” to grow, and the lack of oxygen means the lack of chlorophyll, which will make the leaves yellow - chlorosis. Using a root hormone (Root & Grow) with fertilizer (Espoma Soil Perfector) can help plants recover more quickly.
“My plants have a white powdery covering. What is wrong and what caused this to happen? Is there anything I can do to cure it and prevent it?”
This is a fungal leaf disease called Powdery Mildew, a fungus active when temperatures are cool or cold in standing water. The spore can germinate and inoculate the surface of the leaf. The mycelium then grows across the surface of the leaf, blocking out the sunlight. This can be cured with systemic fungicides (Concern Copper Spray or Espoma 3 in 1) that will prevent and cure the disease. Immunox will stay in the plant tissue for 14 days. Sulfur or Copper in sprays works well. Re-application after rain or watering is required.
“Many of my plants have large notches missing, what is causing it and is there a control?”
Rabbits are the worst offenders, here. Juvenile rabbits do not have the sense of taste or smell so repellents won’t work on them. Hot pepper spray, however, repels juveniles. Keep rotating the repellents to keep the rabbits confused and not trusting of your “restaurant.” Some recommended sprays are Liquid Fence, Bobbex for Rabbits and Repels-All.
The Gypsy Moth larva…
A terrible insect infesting Northern Illinois. The larva are too large to control with many insecticides, so watch out for the adults moths. Contact insecticides, like Bonide Household Insect Control with 4 month residual action can kill the adults, Golden Pest Spray Oil will saturate the egg masses and kill the eggs - currently the only product that will do so.
Tags: ABC 7 Morning News, Chalet Landcaping Nursery and Garden Center