It’s always a bit mysterious when a plant doesn’t bloom. After all, most bloom annually. How then to explain why a plant doesn’t flower at all?
Often one of your friends suggests what seems to be a logical answer. “If your plant doesn’t flower, it’s because it’s a male.” Well, that does sound logical… but it’s totally false. You see, male plants also bloom. In fact, they have to. If they didn’t and therefore didn’t produce pollen, how would female flowers receive the pollen they need to produce seeds?
Perfect and Imperfect Flowers
In fact, the vast majority of flowering plants, about 90%, are said to be “perfect”: that is, they are hermaphrodites (bisexual) and carry both stamens (male) and at least one pistil (female) in the same flower.
When a flower does not have both sexes, it’s said to be imperfect. Some plants, for example, are monoecious: there bear separate male and female flowers on the same plant. Squashes (Cucurbita spp.), begonias (Begonia spp.) and most conifers belong to this group.
About 6% of plants are dioecious, that is, they produce male flowers (with stamens) and female flowers (with a pistil) on separate plants. This is notably the case with hollies (Ilex spp.) and kiwis (Actinidia spp.). Do note though that both plants, although one is male and one is female, do bloom.
So Why Do Some Plants Not Bloom?
Let’s return to the initial problem: how to explain why a plant doesn’t flower. Here are some of the (many) possibilities:
- It’s not mature enough. True enough, some plants bloom within months of sowing, but others wait several years before they start. In the case of large trees, it’s not at all unusual for it to take 40 years before the first flowers appear.
- It may not bloom annually. There are plants that bloom only every two years, and others that flower even less frequently. If you take notice of it in an off year, no, it won’t bloom.
- It has been incorrectly pruned. This is a common occurrence in home gardens. If you prune a plant while it bears flower buds, even if they’re still nearly microscopic, that will keep it from blooming. To avoid this situation, and if you have a good reason to prune (few plants need to be pruned on a regular basis), always prune it after the plant blooms.
- Maybe it did bloom, but you didn’t notice. Not only are some flowers pretty insignificant, but they may also bloom for such a short period or at such odd hours that it’s unlikely you’ll notice them.
- It’s not growing under the right conditions. This is the number one reason a plant doesn’t bloom. The plant may lack light or receive too much light, the soil or air may be too humid or too dry, it may be too cold or not cold enough in the winter or too cool or too hot in the summer, the soil may be too poor (or too rich)… and the list goes on and on. In fact, three cheers for the capacity of plants to adapt to new conditions, because it’s almost surprising that a plant removed from its natural environment and cultivated in a very different climate still manages to bloom, yet so many do.
As a laidback gardener, it’s up to you to grow the plant under conditions the most closely meet its needs. Then all you have to do is wait patiently for it to start to flower!