My Plants Won't Bloom: Troubleshoot Here!

MAY 04

You spend hours pouring over gardening books, magazines, and websites looking for the perfect blooming plants for your gardens. You make your selections, plant your plants and then wait, anticipating a magnificent show. And then…no blooms! Why?! By asking a few questions, you can troubleshoot here:

Are the plants less than three years old? Early on in life, many woody plants go through a period of growth called the "juvenile stage" in which the plant does not flower. During this stage you'll see leaves and new growth, but flowering is prevented by a chemical balance that focuses energy on root development and foliage production.  This stage can last two to three years in shrubs and more than five years in trees. There is nothing you can do to speed this along; be patient and know your plant is doing what it is supposed to do. Age also plays a factor in the blooming of older plants.  Some older plants produce fewer blooms as they age while other older plants bloom magnificently before they die. It is nature's way of producing seeds for future generations of plants.

Do you have crape myrtles that aren't blooming? Crape myrtles are one of the last trees/shrubs to leaf out and do not flower until late summer. Newly planted crape myrtles may bloom very sparsely or not at all for the first few seasons after being planted. Make sure it's getting at least 5-6 hours of sun; crape myrtles need that sunshine to bloom!

Do you have lots of foliage but no blooms on your hydrangea? Lack of flowering in plants can also be related to improper pruning. Prune spring flowering trees and shrubs immediately after they bloom. If you prune these plants during the summer, fall or winter, you will be removing next season's flower buds. For summer blooming plants, such as crape myrtle, roses and butterfly bush you should prune in late winter or very early spring. Hydrangeas can set buds on old, new or both types of wood. If you aren't sure, a good rule of thumb is to prune right after they finish blooming.

Are your plants lush and green, with very few, if any, blooms? If you know you have pruned properly, the problem could be a soil/fertilizer imbalance. Nitrogen, an element in fertilizer and often used in higher ratios for lawn treatments, pushes vegetative growth.  If you have your lawn treated, chances are you have higher levels of nitrogen in your soil. To restore balance, add phosphorous-rich fertilizers or bone meal. You can also water the plant thoroughly to wash the excessive fertilizer through the soil. It may require a year or two before the effect will be apparent on trees or shrubs. Annuals and roses, on the other hand, are heavy feeders and require ample fertilizer to bloom profusely throughout the spring and summer.

How has the weather been? Temperature can play an important role in the flowering of many plants. When winter temperatures are extremely cold, flower buds may be killed; and therefore, the plant will produce fewer flowers. Usually you can see the brown and dead flower buds on the plant. The same situation can happen in the spring if there is a late freeze. Flower buds which have swollen and are ready to bloom may be killed if temperatures drop below freezing even for one night.

Do your plants sometimes flower well one year and not at all the next? Some plants are subject to a phenomenon called "alternate flowering." This type of plant will flower heavily in one year and then fail to flower for one or two additional years. This is a natural phenomenon and there is nothing you can do to prevent the occurrence. Flowering dogwoods and crabapples are often subject to alternate flowering.

Are your plants getting the light they need? Sun loving flowering trees and shrubs require at least 6 hours of full sun to bloom profusely. If there is not enough sun, the plant may grow, but won't flower as expected. Shade loving plants still benefit from a few hours of morning sun to bloom well. Flowering trees and shrubs which are planted in very shady spots will produce few or no blossoms.