I have two magnolia trees that are more than 5 years old and will not bloom; also a big beautiful wisteria that will not bloom. Can you help me, please?
The Gardener’s Answer
Hello, Pat in Kentucky: Please correct me if I am wrong but I think that I just answered your magnolia question. As far as your wisteria not blooming, these vines can take up to seven years to bloom, sometimes longer. This is especially true for both Asian (Japanese and Chinese) native species. Do you know which one you are growing and if it was grown from a cutting or a seedling? For best results in terms of flower production, vines grown from cuttings are a better choice as opposed to seedling grown vines. In general, native species such as the American wisteria (Wisteria frutescens) and the Kentucky wisteria (Wisteria macrostachys) bloom sooner than the Asian ones. Named cultivars such as ‘Amethyst Falls’ and ‘Clara Mack’ tend to flower sooner so depending on which one you are growing, the age of your vine, the nutrient level, and light availability could all be reasons for the lack of blooms on your vine. Wisteria are really tough plants and opposite of what we typically think of in terms of getting our plants to bloom; they tend to bloom when they are stressed, so severe pruning can encourage to them to bloom. Root pruning as well as shoot pruning is recommended. Late spring or early summer is the best time to prune since these woody vines produce buds in the early spring on old wood. Pruning before then can actually remove potential flowers for the upcoming season. Too much fertilizer is a bad thing for these vines, especially fertilizer high in nitrogen, because it encourages leafy growth instead of blooms. If your vine is not given a minimum of six hours of direct sun it will likely not bloom.