Caesalpinia cacalaco (Cascalote)
Foliage: Semi-Evergreen
Mature Height: 10' - 20’
Mature Width: 10’ - 20’
Growth Rate: Fast
Hardiness: 25 degrees F
Exposure: Full Sun
Leaf Color: Green
Shade: Filtered
Flower Color: Sulfur
Flower Shape: Petals
Flower Season: Winter
Thorns: Yes
Propagation Method: Seed
Sizes Available: #24 and #45
Caesalpinia cacalaco (Cascalote, Mexican Bushbird) is a more recent addition to the desert landscape palette. It is characterized by sulphur flowers that appear in fall and winter, curved, rose-like thorns along the stems, semi-evergreen and hardy to 25 degrees. Flowers clusters appear at branch terminals and can be damaged by freezing temperatures. Foliage is fairly dense and dark green, contrasting sharply with yellow flowers. Stems are dark brown that thicken over time giving maturing specimens a vase shaped, graceful small tree form 10' to 15' tall and wide. It can also be maintained in shrub form by seasonal pruning.
Of the more than 70 tropical and semi-tropical species of Caesalpinia, four (Caesalpinia cacalaco, C. gilliesii, C. mexicana and C. pulcherrima) are well adapted to landscapes in the desert southwest. The genus takes its name from Andreas Caesalpinia who was the chief physician to Pope Clement VII. These four species have in common spectacular flower displays, are adaptable to a variety of landscape uses from a mounding, rounded shrub to a small patio tree.
Of the Caesalpinia species, C. cacalaco and C. mexicana are most adaptable to being trained into patio tree form. In most landscapes they are used as accent, background plantings, in massings (to amplify the effects of the seasonal flowers) and as a border or streetscape planting. Hummingbirds and butterflies visit the blooms. They are all largely free of disease and insect pests and can subsist on limited irrigation. All grow best in full sun in well drained soils with moderate application of fertilizer. They can adapt to lawn and arid garden plantings. Optimum flowering is achieved with a combination of regular irrigation and fertilization.
Cultural Practices:
Foster the development of a more dispersed root system and reduce the risk of wind throw by arranging irrigation emitters at varying distances from the trunk to encourage roots to "seek out" water and nutrients. Irrigation emitter arrangement along with other information on irrigations practices for desert trees can be found at Irrigation Practices for Desert Trees.
Prune as needed to reinforce the structure and form of the tree. Periodic thinning is the most desirable method of pruning. Avoid hedging or heading back desert species, as this will only stimulate excessive branching. Do not remove more than 30% of the canopy during the summer as this can lead to sunburn injuries that can later be invaded by wood boring insects. Always use clean, sharp tools that are cleaned regularly in a 10% solution of bleach. For detail pruning guide see Pruning Desert Trees.
Periodically insect pests can be a problem on some desert trees. On young trees, insect infestation can slow typical seasonal growth. Inspect trees during the growing season for common garden sucking insects such as aphids, thrip, whiteflies or psyllids. During dry months, (May and June) in dusty conditions, spider mites can appear. Monitor for infestation and apply controls as needed. Spray applications of water or water and Safer Soap give short-term control (3 to 7 days) for small insect population. For heavy infestation or longer control use federally registered insecticides. A contact insecticide application will kill existing adults. An application with a systemic soil drench will provide 8 to 12 weeks control for any post application insect hatchings or migration of insects. Before using pesticide for the first time or on new plants or cultivar, treat a few plants and check for phytotoxicty. Always read label and follow label instruction before using pesticides. For pesticide control recommendations contact a licensed pest control advisor.
The information provided here was gathered from research literature published by the University of Arizona, other professional landscape and horticulture organizations and our experience at Arid Zone Trees. Always consult local landscape experts for recommendations for your specific area.