Bougainvillea only grows leaves and won't bloom: causes and solutions

Many people love bougainvillea because it is easy to care for, has a beautiful plant shape, bright flower colors, and a long blooming period. Whether grown as a potted plant or trained to climb in a courtyard, it is very eye-catching. A beginner grower asked, why does the bougainvillea I grow only grow leaves and not bloom? What are the causes? What solutions are there? Let's find out together.

1. Causes of bougainvillea only growing leaves and not blooming

1. Overwatering

Many growers, when they notice their bougainvillea is not producing leaves, mistakenly assume it is caused by a lack of water. So they water it heavily. In fact, this not only fails to help, but may also cause root rot due to overwatering.

2. Insufficient light

Bougainvillea loves light very much. If light is insufficient, its photosynthesis cannot work properly, so leaves will not grow, and even existing leaves may develop problems.

3. Insufficient nutrients

The nutrients referred to here are fertilizers, but this is rarely the reason leaves fail to grow. As long as we fertilize regularly, its nutrient needs can be met. However, the possibility of leaves failing to grow due to insufficient fertilizer cannot be ruled out.

2. Solutions for bougainvillea only growing leaves and not blooming

1. Long sunshine hours and strong light

Bougainvillea needs sufficient light to grow and bloom normally. Even during hot midsummer, it should be placed in a spot with ample light. The optimum temperature for bougainvillea growth is 20-30°C. If light is weak and sunshine hours are short, bougainvillea grows poorly, with thin, elongated branches and pale green leaves, and generally only grows leaves without blooming or blooms very little.

2. Scientific watering measures

Bougainvillea has many leaves and large leaves. Combined with high summer temperatures and high water evaporation, scientific watering measures are needed. In the early summer growing season, appropriately increase watering to promote branch and leaf growth. Around mid-August, control water 3-4 times at the right time to shift vegetative growth to reproductive growth and speed up flower bud differentiation; when flower buds appear in the leaf axils of branch tips, increase watering.

3. Fertilize properly

Because bougainvillea blooms heavily and has a long blooming period, it consumes a lot of nutrients. In addition, potted plants have limited soil and limited nutrients, so nutrients need to be replenished in time. Therefore, during the bougainvillea growing period, pay attention to supplying fertilizer and water.

In early summer, apply one more quick-acting fertilizer mainly based on nitrogen to promote branch and leaf growth; during the vigorous growth period, apply an organic liquid fertilizer mainly based on phosphorus once every 7-10 days, preferably fully decomposed oil cake fertilizer water, to accelerate flower bud differentiation; before and after the blooming period, increase phosphorus and potassium fertilizer. For example, spraying the leaves with 0.3%-0.5% monopotassium phosphate can promote continuous blooming on extending branch tips.

4. Light and ventilation

Bougainvillea is a sun-loving plant. To make branches and leaves grow normally and increase the number of bloomings, bougainvillea must be placed in a location with ample light and good ventilation, allowing it 8 to 12 hours of light per day.

3. How to force bougainvillea to bloom?

Prepare a somewhat large cardboard box. At around 4 p.m. each day, place the potted bougainvillea inside to shade it from light, then take it out again at around 8 a.m. the next day to receive light, and place it in a sunny spot on the balcony, ensuring the bougainvillea can get more than 8 hours of light each day.

Bougainvillea likes fertilizer and light. Doing water control and light-shading treatment before the blooming period can make bougainvillea bloom more and more brilliantly. If you find it troublesome to move a cardboard box around, you can also use a black plastic bag for light-shading treatment.