Saturday, July 17, 2010

Justicia carnea flowering, a hardy perennial in USDA Zone 7?

Usually considered a flowering house plant, I got this at a plant exchange with the claim that it had overwintered several consecutive times in New Jersey. I planted it in the courtyard garden at the Beltsville Library a year and a half ago. It made fairly good growth last year, flowering towards the end of the summer. I had always known it as a Zone 9 plant so I wrote it off as an annual. Recent research reveals that its pretty generally considered a USDA 8 now. If I'd bothered to find that out last year I would have mulched it heavily; I didn't. Last winter was a moderate winter but there were a couple of single digit days so I'd have to say it was a legitimate Zone 7. Of course one year doesn't even begin to tell the whole story, but indications look good for Zone 7. It emerged fairly early this spring unlike many of the "hardy tropicals" that often don't show their noses until late June of July. Also, it didn't start the season with that look of "recovering from a "near death experience" that I often see on tropicals that survived but probably won't for more than a year or two. It came out vigorous with good color, acting like enough root system had survived to allow it to function from the moment it broke ground. If I had to guess, I'd say this one will be dependable.

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