I'm confused. Your question is about Catalpa trees, but you've added 'Solanum pseudocapsicum' as the plant you're asking about.

Well...if it's Catalpa, they will tolerate most soil types - being well suited to heavy clays. Generally a deep fertile soil is best. They can be damaged if exposed to cold areas - preferably plant in full sun in sheltered areas. Prune dead wood in early spring. They don't like very dry or very wet soil.

If you did mean the Solanum, please click on that name under your question, and you'll find some advice there.