Q. Can you tell me about Balloon Plant and if it is helpful for Monarch Caterpillars?
Thank you for your question. Gomphocarpus physocarpus, or Balloon Plant, is helpful for Monarch Caterpillars. Gomphocarpus physocarpus: Asclepias physocarpa is the former botanical name, with common names such as Goose plant, Giant swan milkweed, Hairy balls, Family jewels, Oscar, Cotton-bush, Balloon plant. A perennial for USDA hardiness zone 8 and above. Balloon plant is a fast growing annual for colder zones. Full sun to part shade is best for growing outdoors. Growth Height: 4 to 6 feet (can grow taller). Spacing when planting: 2 to 3 ft. Flowers: white with purple accents. Blooms mid to late summer. A fast growing annual milkweed can sustain lots of monarch caterpillars late season when there may not be much else. Long stems with pods make amazing table centerpiece
Colder hardiness zones must start seeds indoors for hopes of a seed harvest, or overwinter indoors under cfl light bulbs. Flowers are not super showy, but still pretty.
From our library guides: http://libguides.nybg.org/butterflygardens
Just a little extra info: http://www.naba.org/pubs/bg172/bg172_Butterflybush_Issue.pdf
Hope this helps.