Tuesday, June 22, 2010

Amazing (Herb of) Grace

We all love great bargains, and My Florida Backyard is no exception. Recently, we got a great "gift with purchase" - plants that came with caterpillars already on board!

We've been on the lookout for some nice Rue (Ruta graveolens) for the butterfly garden. In addition to being an attractive plant with an interesting medical history, Rue is a great host plant, attracting both Giant Swallowtails and Black Swallowtails. Want some proof? Our rue plants came with a few caterpillars of each kind - free!

If you look closely at the picture above, there are two Giant Swallowtail caterpillars (the ones that look charmingly like bird poo) and two Black Swallowtail caterpillars. The second Black ST is very tiny, and shows the variation of this caterpillar in its earlier instars. (For more on Black ST caterpillars, see Cats in the Cradle and Time Changes Things. Look for more details on Giant Swallowtail caterpillars in a future post.)

Rue is also commonly known as Herb-of-Grace, and was originally found in Europe and Northern Africa. It has long been cultivated around the world, and is extremely well-suited for the Florida garden. It loves hot dry conditions and sandy soil - we've got plenty of both! As a culinary herb, rue has pretty much fallen out of favor - it has a strong bitter taste that most people don't care for, although some Mediterranean cuisines still use it. Like most herbs, it also plays an important part in folk medicine.

The really wonderful thing about Rue is that it is fairly fast-growing, and easy to start from seed. This allows the casual butterfly gardener to provide a host plant for Giant Swallowtails without the need to wait for a citrus tree to grow large enough to sustain a population. Although we're still pleased about the Wild Lime we planted earlier this year, it will take a while for it to grow substantially. Rue provides more instant gratification.

One caution - when combined with sun exposure, the oil from the Rue plant can cause skin blistering in some individuals (including, apparently, yours truly), so be careful when handling until you know how your skin reacts.


  1. Ah hah! That's what happened to my finger!

  2. Congrats on the caterpillars. I didn't know rue was a host plant for them. I'll have to look for some.

  3. I love it...free caterpillars. What a bargain! The rue is a very pretty plant, too. I've never heard of it before. I hope you can get some nice photos of your future butterflies, too.

  4. Thank you for identifying the caterpillars on my rue plant. I sometime have to remove tomato hornworm from vegetable plants, but I was sure that these guys were of a classier nature & are welcome to munch away on my rue.