One of the vendors will probably be selling some at the plant sale this weekend at Thomas Square (corner of King St. and Ward Ave.). Otherwise, you might check Wally's Garden Center in McCully, Star Garden (various locations), or Koolau Farmers (various locations).

I grow penta, of all various colors... they are hardy, and the snails and slugs do not like them. I buy them at Wal-marts but now I have thousands of seeds popping up. I like the dark red the best. Penta have grown up to five feet, I keep them cut for a year around growth. Note that they like full sun to full shade, I have them growing wild under the house. In the shade they grow to about six inches. I live in the windward side of Oahu.