AboutMike Mascio Expertise I have been an avid gardener since 1985 and an AllExpert volunteer since 1998. I specialize in soil preparation, seed starting and plant propagation, flowers, vegetables, and general landscaping. I am a strong advocate of the square foot method of gardening and the use of organic controls for pests and diseases.
Question My petunias and marigolds are not growing and tend to turn a dark color on the leaves. the perennials are great but sometimes don't bloom. What's wrong? I live in western New York.
Answer I would definitely recommend having your soil tested. Many nurseries offer this service. The key is taking samples from three different parts of the garden bed and mixing them in a plastic container. What I suspect is either a nutrient deficiency or a ph imbalance. There's also the possibility of a soilborne fungus disease adversely affecting the plants. It's impossible to speculate which of the three it is without testing the soil.
Since you did mention that the perennials are growing well, but not blooming, there is a high probability that your soil is lacking calcium, iron, and/or phosphorus. The best way to correct this is by adding organic amendments to the soil. These would include aged manure, peat, and compost. They not only improve the fertility of the soil, but also improve drainage and balance the ph level to 7.0, which is neutral.
I hope this answered your question. Good luck, and please write again if I can ever provide assistance.
