X Chitalpa tashkentensis, Chitalpa
Chitalpa is reported to be an inter-generic cross between Catalpa bignonioides and Chilopsis linearis. However, at least one horticulturist believes that it might be a chance seedling sport of Desert Willow (Chilopsis). Drought-tolerance is not surprising considering the native habitat of Chilopsis stretches from Mexico to California and Texas. Plants are well suited for the hot conditions near parking lots.
Chilopsis has been traditionally used in the desert southwest landscapes, but recently some have brought the hybrid to the eastern part of the country. Trees in the east should be located in a very well-drained soil to prevent root rot. Pollen can cause some allergy symptoms.
Despite its tolerance to extended drought, trees in desert climates grow faster and with a more uniform canopy if they receive adequate moisture. Flowering is also best with some irrigation. But established plants suffer if overwatered, so locate them where they will not receive too much water from a sprinkler system. Like other drought tolerant plants, these like regular watering until they are established in the landscape. Irrigation is not needed to keep plants alive after they are established in the eastern part of the country. Occasional water in the dry season helps plants look good in dry climates. Trees cast light shade under the canopy making it easier to grow turf under the tree than under other trees with a denser canopy.