Friday, May 27, 2016

Spider Milkweed Project

Two years ago, I planted seeds of the Spider Milkweed, Asclepias viridis, in one of the garden beds, with the intent that the plants would host the larvae of the Unexpected Tiger Moth, Cycnia inopinatus.  That State endangered moth is primarily known for using Butterflyweed, Asclepias tuberosa, as a host plant, laying its eggs in the milkweed flowers.  I noticed that the Unexpected Tiger Moth had two broods at Blue Jay Barrens.  The early brood appeared prior to the blooming of Butterflyweed and was using Spider Milkweed as a host.  Adults emerging from that brood then layed their eggs on Butterflyweed flowers.  Populations of these two species of milkweeds were located in different areas of the property.  I thought that having the two species growing in close proximity might improve the breeding success of the moth.  Since I already had Unexpected Tiger Moths utilizing Butterflyweed in my garden, I decided to add a population of Spider Milkweed and see what happened.  This is their first year to bloom.

Spider Milkweed is the earliest milkweed to bloom at Blue Jay Barrens.  Shoots were breaking ground on April 18.

This is the same plant nine days later.  Multiple stems radiate from a common root system. 

Barely more than a week out of the ground and a cluster of flower buds has formed.

Plants are currently actively blooming.  I’ve been watching for both moths and larvae, but have seen neither yet.  These plants should produce enough seed for me to plant the rest of this bed to milkweeds and to scatter seeds back into the field where the original seeds were collected.

Sharing the bed with the Spider Milkweeds are Draba cuneifolia, which produced an abundance of seed, and …

Leavenworthia uniflora, which may have set a record for the greatest number of seed pods on one plant.


  1. I'll be looking forward to part two of the blog- the second brood.
    Keep us posted!
    Thanks for the great info, Cheryl

    1. Hi, Cheryl. I'll be sure to follow up with a report on the success of this project.