1) paulonia tree or catalpa? 2) prevent vine borers on zucchini plant

Asked July 5, 2016, 5:06 PM EDT

1. I have many seedlings/saplings of a tree that is planted in my yard that I thought was a paulonia.. I offered these on freecycle, but several people warned me that paulonia trees are invasives and I should not share. In researching the tree, I learned that they are similar looking to catalpas. I do know it gets a pretty, orchid looking flower in spring, but can't recall if it develops the cigar like bean in fall. So---how can I tell the difference and should I share the little trees? 2. Every year, I try to grow zucchini and maybe harvest one squash before the plant collapses due to vine borers. I have cut out the borers in years past and put mud around the cut---without success. Is there a way I can prevent the borers instead of trying to treat after they have arrived? Thanks! Joyce

Montgomery County Maryland

2 Responses

Preventing the adult from laying its eggs on squash using floating row cover works, especially on early plantings. Successive planting should also be considered when growing squash.
Paulownia tomentosa commonly called the Empress or Princess tree, has a leaf similar to the catalpa. The seed pod on catalpa is cigar shaped whereas the paulonia has a capsule containing up to 2000 small winged seeds. The paulonia can become messy and because of its dense shade making it difficult to grow grass . The catalpa is a more stately tree. Suggest keeping paulonia away from a lawn and observe it growing in its natural state along a tree line woodlot.The tree of heaven,Ailantus altissima, is classified as being an invasive species.


I have read that wrapping foil around base when planting is an effective deterrent, and that planting after 7/4 will avoid the borer while still having enough season for harvesting. If use the floating row cover, remember to remove when flowers form so they can be pollinated. Good luck from a gardener in AA county.