“What is the gray powder on the leaves of my plants, and how can I get rid of it?”
Powdery mildew is a type of fungus that grows on plants at the end of the summer, when there are cold nights. On woody plants such as lilac, powdery mildew is only an aesthetic problem, and will not harm the plants. Garden flowers like roses, phlox, bergamont and delphinium are negatively affected by powdery mildew and should be sprayed with lime sulfur to kill the fungus or natural, homemade fungicides. For recipes see: Plant Diseases
“What are the black growths on plum tree branches and how can I get rid of them?”
Black covering parts of plum tree branches is due to black knot, a fungal disease. To control: in the spring when the tree is still dormant, cut the branches that have the fungus off, four to six inches inward from the affected area. Then when the buds start to come out, spray the whole tree with lime sulfur, and repeat seven days later. Make sure all infested trees in the area are treated, otherwise you could have a reoccurrence.
“How can I get rid of weeds?”
- To get rid of weeds in the garden, the best remedy is the simplest: Pull it out. Try to get as much of the roots as possible. Plants will try to regrow from any bit of root that is left. For really bad weeds, don't put them in the compost after you pull them out, throw them out instead. After pulling weeds, mulch the area with grass clippings, leaves, plastic mulch or wool blankets (old ones you don't want anymore).
- Pouring boiling water on some weeds can kill them.
- Having healthy, vigorous plants will also prevent weeds from taking over.