Bougainvillea Winter Care Tips and Common Pest and Disease Control Methods

As is well known, the flowers of the bougainvillea are unusual and beautiful, covering the branches when in bloom. They usually bloom in summer. Bougainvillea needs strong light; in semi-shade it will drop its leaves and flowers. So how should we keep bougainvillea alive in winter?

How bougainvillea overwinters in winter

1. Overwintering location for bougainvillea

Bougainvillea is not cold-tolerant. Once the temperature drops to 6-8 degrees, it needs to be moved to a different spot for care. Bougainvillea cannot survive winter outdoors in the open ground. Placed in a sunny, wind-sheltered spot outdoors, in a double-layer plastic film shed built against a north-facing wall, bougainvillea can overwinter. Alternatively, place it on an enclosed south-facing balcony, on a raised spot 40-80cm high that is wind-sheltered and sunny; overwintering is then relatively safe, and if it can be bagged for warmth, even better.

2. When to move bougainvillea indoors

Move it indoors when the temperature reaches 8 degrees. In the south this is generally mid-to-late November, and in the north around late October.

3. Overwintering care for bougainvillea

Pruning and tying

Before moving it indoors, prune the bougainvillea, keeping the main branches and some flowering branches, to reduce nutrient consumption.

Stop fertilizing and control water

In winter, temperatures are low and water evaporates slowly; reduce watering and keep the potting soil on the dry side. Stop fertilizing to prevent vigorous vegetative growth resuming after being brought indoors due to higher temperatures, which would weaken its cold tolerance.

Bougainvillea enters a brief dormant period in winter and may drop its leaves. After dormancy and leaf drop, water as little as possible; if the soil is too dry, water a small amount (of warm water) locally around the edge of the pot.

Controlling aphids

In winter, when the plant is moved indoors, aphid infestations are very likely before the leaves drop, and timely control is needed.

Increase temperature, ventilate, and supplement light

After moving indoors, place the plant in a well-ventilated, sunny spot with a suitable temperature for care. Usually, pay attention to opening windows for ventilation so the environment does not become stuffy and hot.

When to move bougainvillea back outdoors

Bougainvillea should be moved back outdoors rather late, in late March. On the balcony, as temperatures rise, new buds begin to sprout; by Qingming, some have already begun flower bud differentiation. If moved outdoors at this time, the flower buds may freeze and it cannot bloom in May. So wait until the lowest temperature is stable at 12-15 degrees before moving it outdoors, in April to May. After moving it outdoors, prune away dead branches and useless branches to beautify the plant's shape.

Common pests and diseases of bougainvillea and their control methods

Bougainvillea is also called paperflower. Its common pests are mainly scale insects, and its common diseases are mainly leaf spot and brown spot. With careful care and observation in daily maintenance, similar pests and diseases can still be avoided.

Leaf spot symptoms: The spots are initially yellowish-brown, surrounded by a yellow-green halo, then expand into nearly round or irregular spots with dark brown edges. In the later stage, small black dots appear on the spots.

Control methods:

If a small number of spots are found on the leaves, apply miconazole nitrate cream to them and cut off the branches with more disease. In the early stage of the disease, 50% carbendazim wettable powder at 500 times dilution can generally be used for control, spraying once every 7-10 days. In severe cases, according to the actual situation, spray once more on the fourth day, then once every 7 days. For 3-4 consecutive times, the control effect is good.

Bougainvillea brown spot symptoms: Brown spot mainly harms bougainvillea leaves, producing yellowish-brown to light brown spots with a diameter of 0.1-0.5cm on the leaf surface.

Control methods: When a small number of diseased leaves are found, remove and burn them promptly. In the early stage of the disease, use 70% mancozeb wettable powder at 400 times dilution, spraying once every 10 days, for 3-4 consecutive times.

Bougainvillea scale insect symptoms: In environments with poor light, inadequate ventilation, and high temperature and humidity, various scale insects are prone to infestation. When affected, many small white bumps appear on the leaves, affecting their ornamental value. Later, the scale insects suck the leaf sap, causing leaf damage and affecting plant growth.

Control methods: If a small number of scale insects are found, they can be washed off with clean water or scraped off with a bamboo stick.

In severe cases, 45% malathion emulsifiable concentrate at 1000 times dilution can be sprayed to kill them. For home care, try not to use chemical pesticides; even when promptly spraying biological agents, pay attention to the concentration to avoid affecting family health.

The habits of bougainvillea

The suitable growth temperature for bougainvillea is 15-30 degrees Celsius, of which May to September is 19-30 degrees Celsius, and October to April of the following year is 13-16 degrees Celsius. In summer it can tolerate high temperatures of 35 degrees Celsius, and in winter the ambient temperature should be maintained no lower than 5 degrees Celsius, otherwise it is prone to freezing and leaf drop.

Bougainvillea likes light and is a sun-loving flower. Insufficient light during the growing season will cause the plant to grow weak and affect bud formation and blooming. Therefore, throughout the year, except that newly potted seedlings should first be placed in semi-shade. In winter it should be placed by a south-facing window.

Bougainvillea likes loose, fertile, slightly acidic soil and dislikes waterlogging. When potting, use one part each of leaf mold, peat soil, sand soil, and garden soil, and add a small amount of decomposed cake residue as base fertilizer, mixing them into a potting mix. Flowering plants should be repotted and the soil changed once a year, preferably before budding in early spring. When repotting, use scissors to cut off overly dense and aged branches.

In spring and autumn, water once a day; in summer, water once each morning and evening; in winter, when temperatures are lower and the plant is dormant, watering should be controlled, and it is best to keep the potting soil in a moist state.

When to prune bougainvillea

When growing bougainvillea, it can actually be pruned all year round, usually multiple times, but not excessively.

Pruning bougainvillea is generally done after the peak flowering period. Once the peak flowering period has passed, prune and cut off all the remaining flowers. This can reduce nutrient consumption and accumulate nutrients for the bougainvillea's next bloom.

Pruning during the growing season is generally for shaping the bougainvillea. See which branches are not suitable to keep and cut them all off. This can also encourage side growth and increase the number of flowering branches.

In daily pruning, you need to prune those branches with poor growth and maintain the plant shape so it reaches its best state. After flowering, besides cutting off the spent flowers, also cut off branches that affect growth and ornamental value. The remaining branches do not need pruning; just tidy them slightly, and do not prune heavily.

Having said all this, it is not easy to care for and cultivate a bougainvillea well. In our lives, bougainvillea can be seen everywhere, blooming in masses, with red flowers and green leaves enhancing each other, offering a uniquely fresh flavor. Although bougainvillea is not perfect, it gives people a feeling of calmness, not at all delicate or artificial. The more brilliant the sunshine, the more gorgeous the bougainvillea.