View source for Catalpa bignonioides

==Cultivation==
Prefers a good moist loamy soil and a sunny position that is not exposed[1, 11]. Tolerates heavy clay soils[200]. Very resistant to atmospheric pollution[188]. Plants become chlorotic on shallow alkaline soils[202]. Plants are hardy to about -15°c, probably more in continental climates[200], they grow best in areas with hot summers[188]. Protect plants from late frosts when they are young[200]. A very ornamental plant[1], it is fast-growing in the wild where it often flowers when only 6 - 8 years old[229]. The sweetly-scented flowers are borne in forked panicles at the end of branches[245]. There are some named varieties selected for their ornamental value[188, 200, 202]. The trees transplant easily[200]. The crushed foliage has an unpleasant smell[202]. Another report says that the leaves are attractively scented when bruised[245]. Plants in this genus are notably resistant to honey fungus[200].

===Propagation===
It is easily raised from seeds which germinate early in the first season.  It also multiplies readily from cuttings.

Seed - best sown outdoors, or in a cold frame, as soon as it is ripe[200]. Stratify stored seed for 3 weeks at 1°c and sow in spring[200]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in a cold frame for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Softwood cuttings, 10cm long, in a frame. They should be taken in late spring to early summer before the leaves are fully developed[200]. Root cuttings in winter[200].

===Pests and diseases===
The tree is fairly free from fungal diseases and has few insect enemies.<ref name=Keeler />