When plants won’t flower

I have been writing garden articles for many years, and am very frustrated when gardeners ask me why certain plants won’t bloom and I don’t always have an answer.  When they ask me why their lilacs don’t bloom, I usually know the answer to that. It could be due to the fact that they’ve pruned the lilac in early spring before bloom time or in the fall. Spring bloomers like lilacs set buds that will be flowers next spring right after the current year’s bloom so late pruning removes those buds. University of Minnesota Extension Horticulturist Mary Meyer states that come spring, these plants just don’t have the energy reserves to set new blooms.
Mary also writes that peonies that were recently transplanted or planted too deep is a key reason why peonies fail to flower. Peony buds need exposure to cool temperatures, which they get when they are planted 1 ½ inches below the soil surface. Any deeper and the flower buds may not get cold enough.
Tulip bulbs decrease in size as they age, and the bulbs lack the capacity to produce more than just a few leaves and no flowers. If your tulips aren’t producing any flowers it may also be that the deer have been feeding on them.
With apples, the age of the tree can affect flower formation. Some kinds like the Zestar variety seem to flower at a young age, which is faster that the Honeycrisp variety.  At the Almelund Threshing show, we get lots of questions about apples and a common one is, “Why don’t my apple trees flower or produce fruit?” Dwarf and semi-dwarf apple trees will produce two to three years earlier than standard trees. I keep good records on my apple orchard, and at least three times in recent years I had a killing frost at bloom time which killed the flowers and cut the yield. One year I got exactly five apples on sixty apple trees.
Mary’s article goes on to say if you are having trouble with plants flowering, you should consider the site. A shady site will limit what plants can grow and flower and plants that flower and produce fruit require full sun which is 8-10 hours of sunlight for the best performance. Plants that grow well in shade to part shade are hostas, ferns, and coral bells. I even have some daylilies that have adapted to shade and flower nicely.
Compacted or shallow soils will limit the size of the plant by reducing the root system.  Sandy soil is low on nutrients, keeping plants from reaching their full potential. Have a soil test done to learn what amendments you can add to the soil to enrich it. If your sunny spot has become shaded due to other larger plants like trees, consider removing or trimming back those trees or larger plants. Above all, choose the right plant for the right spot whether it’s shady, sunny, dry or wet and incorporate good organic compost to improve your garden site.

Leave a Reply

Your email address will not be published. Required fields are marked *