Laburnum Facts

Size and Geography

• The common laburnum remains small enough at between 15 to 25 feet for use in landscapes lacking lots of space. The tree's leaves are deciduous, coming off in autumn with no "significant" color, according to the Missouri Botanical Garden. Common laburnum does not tolerate either extreme cold or heat, growing between U.S. Department of Agriculture plant hardiness zones 5 and 7.

Features

• The hanging clusters of flowers that emerge on the common laburnum resemble those of a wisteria vine. The clusters, called racemes, grow between 4 and 8 inches in length. During May and June, the yellow flowers open up. They eventually morph into 2-inch-long seedpods containing the fruits, which are similar to peas. The leaves are trifoliate, meaning three leaflets combine on one stem to form a single leaf. The leaflets, as long as 3 inches, are shades of green and hairy on the undersides.

Growing Tips

• Place a common laburnum in full sun or partial shade. Select a site that drains well and has rich soil. In the hotter areas where common laburnum grows, within zone 7, find a place to put this plant that gets some afternoon shade in summer. The optimum climate for a common laburnum is one that has no huge variance in temperature from summer to winter; the Pacific Northwest is a good example. Removing the seedpods once they emerge helps the laburnum conserve energy and takes away the threat from anyone encountering the poisonous seeds. Using gloves when working with a common laburnum is prudent.

Laburnum Hybrid

• Laburnum x watereri is a hybrid from of common laburnum that has a reputation for being a superior landscaping plant. It generates the same showy yellow flowers, but in hanging racemes as long as 20 inches. This form of laburnum grows between 12 and 15 feet tall, making it suitable for use on patios or in group plantings.