Bougainvillea

Bougainvillea

Bougainvillea can be used as a house plant or hanging basket. In the landscape, it makes an excellent hot season plant, and its drought tolerance makes Bougainvillea ideal for warm climates year-round. It is native to the coasts of Brazil and has a high salt tolerance, which makes it a natural choice for every region. As a woody clambering vine, Bougainvillea will stand alone and can be pruned into a standard, but it is perfect along fence lines, on walls, in containers and hanging baskets, and as a hedge or an accent plant. Its long arching branches are thorny, and bear heart-shaped leaves and masses of papery bracts in white, pink, orange, purple, and burgundy. Many cultivars, including double flowered and variegated are available.

flowering

Blooms occur only on new growth, so new growth on plants is vital to the achievement of flowering. Bougainvillea normally flowers during the short days of winter, but blooms are highly dependent on temperature.

control flowering

Bougainvillea will flower sooner and more profusely with high light intensities, moderate temperatures, and longer nights. Short day lengths enhance flowering: 8-11 hour day lengths with high light intensity and temperature above 14-18oC. Heavy shade inhibits flowering. Drought stress can stimulate flowering even under long day lengths.

cultural practices

Pruning plants too frequently will inhibit flowering. Too much fertilizer will add growth but inhibit flowering. Nitrogen and phosphate are critical to flowering, but do not over fertilize. Keep soil moisture on the dry side.

cultivation practices

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    climate and spacing

    Well-drained, slightly acidic (pH 5.5-6.0) with good aeration and drainage is ideal. Avoid soil mixes with high peat levels and water retention. Bouganvillea grow best in full sun. High light intensity is required for good flowering. Low light and shady areas are not suitable, as the plants will drop their bracts.

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    propagation and media

    Bougainvillea roots best from semi-hardwood cuttings with 5-9 nodes in length.

    Bougainvillea has an extremely fine root system, and should be planted in well-drained soils. It takes 6-12 weeks for rooting. Transplant young plants with caution to avoid damaging the roots, and always apply a broad-spectrum fungicide drench when planting cuttings and again after transplanting to prevent root rot.

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    Plant growth regulators

    To induce lateral branching, applications of BA (benzyl adenine) at 50–100 ppm can be made when the plant tips are pinched back. Apply one spray 24 hours after the first pinch and another spray 24 hours after the second pinch. Dikegulac sodium at 14 g/litre can be used for second pinch-plus-BA application to improve branching.

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    irrigation and flowering

    Bougainvillea tolerates drought and if possible irrigation should be adjusted to be a little on the dry side. They are sensitive to overwatering but should not be allowed to completely dry out.

    Blooms occur only on new growth, so new growth on plants is vital to the achievement of flowering. Bougainvillea normally flowers during the short days of winter, but blooms are highly dependent on temperature.

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    fertilizer

    Bougainvillea needs regular fertilizing with formulations having NPK ratios of 1:1:1 or 2:1:2. Applications of soluble minor elements help prevent leaf chlorosis. Micronutrient applications can be half the recommended rate, twice a year.

     
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    pruning

    Regular pruning is necessary to shape the plant and direct its growth because the shoots often grow vigorously. Flowers are borne on new growth, so pinching back and pruning is necessary to induce new growth. Pruning should be done after flowering has finished, as this encourages the new growth on which the next flush of flowers will occur.