Garden Detective: Getting rid of cottony scale
Cushiony scale on blueberry twings growing in reader Kathy Mosinka's Valley Stream garden. Credit: Handout
Pick or rub them off by hand or with a toothbrush, and give your plant a nutritional boost in spring with a dose of fish meal, blood meal or feather meal.
Thinning plants by removing crowded branches will help to increase air circulation throughout the plant, decreasing susceptibility to powdery mildew and other fungal diseases. Spraying healthy plants with one tablespoon of baking soda diluted in a gallon of water will work as a preventive, but to eradicate an already existing infection you'll get better results if you spray with a fungicide labeled for use against powdery mildew.
Be sure to clean up fallen leaves and other plant debri, and dispose of it all in the trash to prevent a reinfection next year.
The brown spots on the underside of your gardenia's leaves are likely scale insects. Scale secrete a sticky substance called honeydew after feeding on plant sap. And it's the honeydew that attracts yellow jackets (and ants). Rinse the plant with a strong spray from a garden hose to remove any other insects. Then, apply horticultural oil spray to remove the scale, taking care to coat the undersides of leaves.
Once indoors, gardenias will require regular watering, the most sunlight possible and a humid environment that isn't too warm. They won't likely bloom indoors but should remain healthy if those needs are met. Your plants also will benefit from applications of a slow-release azalea fertilizer, which will fortify them for another round of blooms next summer.
Once that happens, even if replanted in loose soil, roots won't be able to stretch outward unless they're "teased," or loosened, to enable them to resume normal growth. This also explains why your plants failed to thrive: Their roots, whose job it is to bring water and nutrients to the plant, and anchor it into the soil, couldn't function properly.
It's always a good practice to slip plants gently out of their pots at the nursery before purchasing, so you can check the condition of the roots. But mildly to moderately pot-bound plants don't necessarily need to be avoided.
To tease the roots, scrape a pair of pruning shears or scissors around the outside of the rootball. Sometimes, I just snip inch-long sections all around; sometimes, I just pry the bottom of the root ball apart with my hands. Any of these methods will free the roots and stimulate them to grow outward into the surrounding soil.
