Rue is my favorite for black swallowtails and the occasional giant swallowtail. Where are you in MO? I'm in St. Louis and would be happy to share seeds. They grow readily, and it's a very pretty and hardy plant. If you are in St. Louis, rue plants can be found at Greenscape Gardens in the county and at Bowood Farms in the city.

Appreciate your offer very much but I just ordered it on Baker Creek Heritage seeds on the Internet. It was a great price only $1.75. Thank you so much for offering. Going to start a butterfly garden and heard it was so good for them.

I have one plant as a backup plan for late season GSTs in case I still have pillars after all the hoptree leaves fall. I don't recommend it as a primary hostplant because it can cause you problems.


The Danger of Rue

I've used rue for years and never had a problem. I handle it at least once a day during the spring/summer looking for BST eggs. Like anything, see how it affects you. It is my favorite host plant because it's pretty on its own and grows quickly to replace the stems I cut for my caterpillars.

I can handle poison ivy without a problem but I get rid of it because others are allergic to it. I also only mess with poison ivy when necessary because I know that my immunity to it can go away as I age. The same is true with rue.
Allergy to rue

Hoptree is a small tree native to Missouri that hosts giant swallowtails and tiger swallowtails. It is easy to raise the caterpillars right on the tree using wedding bags.

Golden Alexander is a plant native to Missouri that hosts black swallowtails. The leaves are much bigger than the usual plants people use for black swallowtails and that is why I never run out of food for my BSTs versus the many other people who do. But because it is tough to spot BST eggs/pillars on Golden Alexander, I also have other hostplants. I have learned the ideal time (end of July in my area) to plant dill seed so I can maximize the number of BST pillars I get to raise. Mama BSTs prefer to lay their eggs on the young dill and it is easier to spot the eggs on dill versus other BST hostplants. I also grow parsley the entire season. Has the side benefit of making my sister-in-law happy when I show up to her house with fresh parsley.

Sensitivity to the effects of rue can vary widely. When I was a buyer for a local nursery, my daugher helped there during her summer vacations and one of her tasks was helping to unload new deliveries and tag the new plants. She unloaded two flats of rue and immediately felt a stinging, itchy feeling on her bare arms where they came into contact with the plant. The next day her arms were covered with large blisters that persisted a long time. To this day, some 15 years or so later, she still has scars on her arms from the reaction to the rue!

OTOH, I have handled rue countless times, also many other reaction-inducing plants, and never had any reaction at all.

KC...I'm in zone 6a too. Isn't July too hot, too late to plant dill ? Never did it before but planning to do it in spring.

Also what are wedding bags ? We have an old

hop tree in the woods down by the river.

Thank you so much for that. Now I have some more to study up on.

This is such an interesting hobby. So much to to look forward to.

Yep, I'm doing the wedding bags on my wafer ash/hop tree next year. Almost all of the Giant Swallowtail eggs that I brought inside didn't make it. The few caterpillars I found that were already 2nd instar did fine.

Sounds like a very wise move.