Plant Watering Requirements for a Bougainvillea

Bougainvillea flower more with minimal watering.

Bougainvillea produces cascades of brightly colored pink or purple flowers throughout the summer months. A tropical perennial, bougainvilleas grow in most climates, though they may need overwintered indoors. Proper watering encourages the most blooms and helps ensure a long and abundant flower display.

Soil and Moisture

Bougainvillea grows poorly in heavy wet soils. Soils rich in organic matter provide optimum drainage but don't dry out too quickly, which helps ensure the roots have access to the correct amount of moisture. Compost amendments improve the drainage and moisture qualities in both clay and sandy soils. In areas with extremely poor soils, planting bougainvillea in a raised bed or container filled with quality soil provides the correct moisture qualities for healthy plant growth.

Bedding Plants

Since bougainvillea flowers best in full sun, beds may dry out quickly which necessitates more frequent watering but too much moisture inhibits flowering. Spreading a 2-inch layer of mulch over the bed after planting keeps the soil cooler so moisture doesn't evaporate out as quickly. A well-mulched bed requires watering every seven to 10 days except for in extremely dry weather when more frequent irrigation is necessary to prevent decline.

Container Plants

Many gardeners grow bougainvillea in containers so they are easily moved indoors during the winter months, since the plants can't tolerate frost. Container-grown plants require more frequent watering because soil in containers dries out much more quickly. Watering when the top inch of soil feels dry until the excess moisture drains from the bottom of the pot ensures the entire soil ball becomes moistened. Potted bougainvillea may require daily watering during the hottest part of the season.

Forcing Bloom

While bougainvilleas perform best in soils that remain moist throughout most of the year, during the flowering period some drought stress encourages a more abundant blossom display. Both bedding and container plants flower best when the soil is kept slightly dry from spring until the flower buds begin to swell. Watering only when the leaves begin to show the first signs of wilt, then allowing the soil to begin drying again before the next irrigation encourages the buds to form and open.

References

• Texas A&M Extension; Growing Bougainvilleas; Samuel Cottner, et al.
• Louisiana State University Extension; Bougainvillea; February 2010