Growing Common Hop Trees From Seeds - (Giant Swallowtail Host Plant)

 

How to get started with Growing Hop Trees from Seeds

As spring has finally arrived in Ontario, it's time to start growing a new supply of host plants for the Giant Swallowtail!

The Giant Swallowtail caterpillar has a small number of host plants to feed on, and I have been trying to include all of them in my garden.

They include the Common Rue (Ruta graveolens), Common Hop-tree (Ptelea trifoliata) and American Prickly-ash (Zanthoxylum americanum).

Unfortunately, most garden centres and nurseries do not carry any of the above-mentioned plants. You may have to search your local phone book for "Native Nurseries" to find them.

Last year I was able to purchase Common Rue. You may find this perennial herb at your garden centres in the herb or perennial section. Common Rues has the advantage that it is a host plant as well as an edible and quite healthy herb.

Also, since the Common Hop Tree is a member of the citrus family and you may have success attracting Giant Swallowtails to your garden by growing lemon and orange trees on your patio during the summer months. 

Keep in mind that hungry caterpillars will devour leaves quickly and it may not feasible to raise Giant Swallowtail larvae on small potted citrus trees in our climate.

Personally, I have not tried Citrus trees, for this reason, and the fact that they are not native to Ontario. I am sticking with native plants and have started getting my Hop Tree seeds ready.

 

Stratification

 

Hop tree seeds are among the seedlings that require a stratification period.

This means seeds cannot be stored inside, rather they have to go through a natural cold, freezing period just as it happens in nature.

A jar of seeds was already stored in my unheated garage and I added to the batch seed I picked from my Hoptrees and shrubs growing in the garden. The seeds are unattractive to wildlife like birds or squirrels and you will find them overwintering quite nicely on your shrub/trees.

Last year was my first year growing hop trees and I was successful to grow three trees from dozen+ seeds collected.

Starting The Seedlings

 

After having soaked my seeds for a few days in water, I have now transferred them into a mix of potting and seedlings soil mix which must be kept moist during the germination period. 

The seeds may "look a little crowded" but from my experience last year they are very easily transferred into single pots, once they have sprouted.

And the wait begins .... 

stay tuned, as I will update the growing process!

Plants will be going for sale for a small fee to cover the cost and support Giant Swallowtail Butterflies!