Hibiscus plants are beloved all over the planet for their big, colorful blooms and relatively easy care.
These plants are most often grown in the garden, but many species and cultivars can also be grown indoors, allowing people to enjoy these wonderful plants in colder climates.
However, just because a plant is easy to grow doesn’t mean it is immune to the occasional problem.
Perhaps the most frustrating of these problems is when your prized hibiscus suddenly decides it doesn’t want to produce flowers this year.
Thankfully, a failure to bloom is often easily fixed once you identify the problem.
Reasons Your Hibiscus Is Not Flowering
There are many reasons a hibiscus plant will fail to bloom, but they all come down to simple care issues that will usually disappear once addressed.
The following causes are all known to prevent blooming in hibiscus plants, both in the garden and those grown in a container.
The root of most problems (no puns intended) is a poor watering regimen.
Underwatering the plant, especially in hot or arid conditions, can lead to stress and dehydration.
The leaves will begin to wilt, and the plant will stop producing flowers to try and redistribute what water it has as best it can.
Likewise, overwatering can actually choke the roots, preventing them from absorbing moisture or nutrients.
Poor soil quality can affect how much water a plant can absorb, either by draining it out too quickly (sandy soils) or being unable to drain (clay soils).
This will lead to the same effects as if you were overwatering or underwatering.
To fix, switch to using the soak-and-dry method and make sure the soil is nice and loamy with some perlite added to keep it draining properly.
Here are the following steps to do:
- Stick your finger in the soil and water if it feels dry 1″ to 2″ inches deep.
- Always use room temperature water and pour slowly and evenly around the plant, avoiding the foliage.
- When the ground can no longer absorb as fast as you’re pouring (or you see moisture seeping from the drainage holes of a potted plant), it’s time to stop.
This is the one factor that can’t be easily controlled when growing your hibiscus bush outdoors.
These plants prefer a moderate to high humidity level and will do well at 40 to 80% percent humidity.
Lower humidity levels will stress the plant and prevent budding or even cause existing buds and flowers to wilt and fall off.
While you can’t control the humidity outside, you can at least provide some relief.
Grouping plants, be they indoors or outdoors, can help to improve humidity through transpiration.
Transpiration is similar to sweating and accounts for more than 97% percent of a plant’s water.
This process raises the humidity around a plant to a small degree, but grouping plants can multiply the effect.
Container plants also have the option of pebble trays and humidifiers.
A good humidifier can do a lot for a plant without impacting the rest of the room.
Pebble trays form a similar function using more primitive methods.
It’s simply a tray or shallow container filled with pebbles or aquarium stones.
Sit your hibiscus plant on top of the tray and add water to it so it doesn’t quite cover the stones.
As the water evaporates, it will provide humidity for the plant without affecting the soil moisture levels.
Too much of a good thing can be very bad, and it’s not uncommon for hibiscus flowers to fail when there are too many or too few essential nutrients.
Nitrogen is one such nutrient and is essential for healthy foliage.
However, too much nitrogen will cause a plant to focus on new branches and leaves instead of flowers.
Find out What is a Good Hibiscus Food.
Phosphorus is another key nutrient that is usually important for full, healthy blooms.
However, hibiscus plants are sensitive to phosphorus buildup, so too much will stall their ability to bloom.
It should be noted that too much phosphorus will also leech potassium out of the soil.
Potassium is the third essential nutrient for plants and is a vital element of a plant’s immune system.
Ideally, you should be giving your plant a balanced liquid fertilizer, mainly if it contains essential trace minerals such as zinc and iron.
The soil should also have a slightly acidic pH, as alkaline soils can prevent blooming.
Fertilizers with natural organic compounds and amendments such as peat moss can help feed your plant and help maintain the acidity level.
There are a lot of plants out there that can tolerate shade, but hibiscus isn’t among them.
In fact, accidentally placing your hibiscus in a shadier portion of the garden can stunt its growth and prevent it from blooming.
Even if it does bloom, you won’t get a very impressive display, and the flowers may be sickly or short-lived.
Your hibiscus plant needs at least 6 hours of full sun per day for proper growth and the best blooms.
In particularly harsh climates, it’s okay to have this full exposure in the morning or evening with a bit of shade or dappled sunlight in the afternoon.
If you suspect your plant isn’t getting enough light, you can prune back any obstructing trees or shrubs, or you might need to transplant it to a sunnier spot.
While less common, some hibiscus plants are grown indoors, in which case you can simply move the container to a sunnier south-facing window.
Finally, the hibiscus is adapted for a temperature range of 60 to 80° degrees Fahrenheit.
When the temperature gets hotter, it can stress the plant, resulting in wilted leaves, bud drops, or failure to bloom.
Conversely, when the temperature dips below 60° degrees Fahrenheit, the plant may attempt to go dormant and might even suffer damage as the temperature drops.
It’s not always easy to protect an outdoor hibiscus from such changes. Still, a thick layer of mulch can sometimes help against brief temperature drops, and you may need to give the plant some afternoon shade during scorching summers.
Hibiscus plants grown in pots are much easier to treat, as you can simply move the plant or bring it inside until the temperature returns to acceptable levels.