Bougainvillea

Bougainvillea Plants and Varieties

Bougainvillea, a brightly coloured climbing plant, thrives in a wide range of climates, from temperate to tropical. Many gardeners have successfully grown them in pots and containers. Keep an eye out for new cultivars, including dwarf, trailing, and standard varieties, which are readily available.

With a multitude of varieties, Bougainvillea flowers come in various colours, from white to deep pink. While they can be trained or pruned into standard plants and grown in containers, they are typically used as climbing plants.

Bougainvilleas are natural climbers, and in their native habitat, they often weave through trees with their roots in cool soil, reaching for the sun. They adapt well, whether trained to cover a fence, draped over a pergola or arch, or grown on a pole or column. The lower-growing varieties can serve as ground covers, form mounds, or even create a semi-formal hedge. Remember that their thorns can be sharp, making them effective natural barriers.

For good flowering, plant them in a warm, frost-free location with well-drained yet moist soil. Bougainvillea plants are available for sale online.

Dwarf Bougainvillea, also known as Bambino Bougainvillea, is the latest addition to the market. These are perfect for pot or large hanging basket cultivation and can also be grown as standards with some selective pruning that is not difficult to do.

Bougainvillea glabra is a naturally smaller growing species with flower colours ranging from white to purple. It’s long-flowering and a sought-after garden plant. The larger Bougainvillea spectabilis features cream flowers and red to purple bracts. Lastly, Bougainvillea peruviana is more of a scrambling and less dense variety, with crimson flowers ranging from light to dark and offering repeat flowering.

Also, there are hybrids that combine traits from these three types.

It’s important to note that not all dwarf varieties grow the same way. Some may reach around 1 meter, while others can grow up to 3 or 4 meters. This is still much smaller than the larger types, which can easily reach heights of 15 meters or more under favourable conditions.

How to grow Bougainvilleas

Just like most plants, you need to prepare the soil first. If you’re using pots, use a high-quality potting mix, and since Bougainvilleas are relatively nutrient-hungry, regular application of a high-potash fertilizer is necessary.

You’ll need a humus-rich, moist, and well-drained soil for Bougainvilleas. They thrive in a bright, sunny spot, but try to provide some shade for their roots by mulching around the base. Keep in mind that they don’t like to be disturbed once planted; their roots are quite delicate and can easily break, so take care when planting.

Bougainvilleas can also be grown in pots if desired. During the flowering period, they need plenty of water, but be careful not to over-fertilize, as this can result in lush foliage with fewer flowers.

When it comes to watering, exercise some caution. While these beautiful flowering plants don’t like to dry out too much, their flowering is more prolific during the warmer months when the soil is somewhat dry.

Pruning Bougainvilleas

Pruning is important to keep your Bougainvilleas in shape, control their size, or train them as standards. You can prune twice a year as needed.

Sometimes, Bougainvilleas may produce long water shoots, which can be trimmed or removed.

Propagation

Propagation from cuttings is fairly simple. Take a 15 cm semi-hardwood cutting, apply rooting hormone powder if desired, and place it in a warm, shaded area with humidity until new growth emerges. Keep it consistently moist. Before planting it outdoors, allow it to acclimate and become hardier.

Grow Flowers not Thorns

Bougainvilleas tend to develop more thorns when they are growing vigorously. This can result from over-fertilisation and aggressive pruning. During rapid growth, the flowers that appear on the left axils are replaced by thorns.

Excessive watering can also lead to flower drop and the growth of thorns instead.

So, if your Bougainvilleas are becoming thorny rather than producing flowers, it’s best to stop fertilisation and avoid overwatering. Another strategy is to grow them in containers, where their root growth is restricted, increasing the likelihood of better flowering.

Is there such a thing as a thornless Bougainvillea?

As its name suggests, Bougainvillea arborea is almost thornless and grows more like a tree. However, currently, this variety is not available in Australia. On the other hand, the dwarf varieties have significantly smaller thorns.

Summary Information

• Soil – As long as the soil is well drained, these plants are not fussy.
• Position – Best grown in full sun.
• Height – The height they will grow depends on variety – dwarf types from 1 to 2m, larger types to 12m.
• Flowers – Papery flowers in various colours from white through to red, purple and orange. Flowering is reduced in shaded areas.
• Flowering time – Long flowering in warmer climates. In cooler climates, flowering time is spring to summer.
• Leaves –  Foliage is alternate, mid green and on thorny stems.
• Pruning – Best time for pruning is after flowering.

Problems

A lack of flowers is usually due to insufficient sunlight, with the plant needing at least 6 hours of direct sunlight daily (not filtered sunlight) as a minimum for good blooms. Insufficient sunlight encourages more foliage growth.

Excessive watering can also hinder flowering. Spring and autumn often provide better flowering conditions than the peak of summer.

When growing in containers, ensure the pot is large enough but not too large – almost potbound is ideal. As the plant grows and the potting mix becomes exhausted, you may need to repot it but take care not to disturb the roots.

Bougainvilleas can be affected by frost, so it’s advisable to avoid frost-prone areas. In cooler climates, avoid planting them in areas exposed to cold winds, as this can lead to tip burning.

Varieties and Uses

You can find dwarf cultivars that grow to around 60cm. They can be used to create mounds, standards, or even serve as ground cover plants. Some cultivars have a weeping habit and can be used as trailing plants or in hanging baskets. One example is the ‘Klong Fire‘ variety, which is both dwarf and semi-thornless, featuring beautiful red flowers, and it’s available at retail nurseries.

Other Climbing Plants

• Clematis
• Mandevilla
• Lapageria
• Climbing roses
• WisteriaWisteria
• Hardenbergia (happy wanderer)Hardenbergia (happy wanderer)
• Pandorea (bower of beauty)Pandorea (bower of beauty)
• Lonicera (honeysuckle)

Bougainvillea not Flowering?

These plants require sunlight to flower, preferably at least 6 hours a day, and they appreciate some humidity. Additionally, when a Bougainvillea has undergone heavy pruning, it tends to focus on new growth (as self-preservation) rather than producing flowers.

Another theory suggests that they flower more abundantly when their root growth is restricted, such as when they are potbound. Therefore, it’s best not to use pots that are too large for the plant.

Avoid overwatering and excessive fertilising, as this can promote vegetative growth rather than flowering. Using a bit of sulfate of potash can help encourage flowering.

Bougainvillea varieties are available for sale from the following nurseries

 

DIACO'S GARDEN NURSERY
Online and Retail Melbourne and Geelong based garden centres. Check out their large range of indoor and outdoor plants, Australian Natives, Fruit Trees and Edibles, Succulents, Gardenias, Camellias, Hydrangeas plus a full range garden products for delivery in Melbourne.
www.diacos.com.au