Showy Milkweed (Asclepias speciosa)

I planted my milkweed research plot on June 21st.  Just one week later, on June 29th, I had 3 monarch eggs on my showy milkweed plants (and no eggs on any other milkweed species).  By July 2nd, a caterpillar had emerged.   It was so exciting to have those first monarchs to watch!  Look on the photo below for the larva's little black head on this showy milkweed.  The caterpillar has just emerged, and before starting its milkweed diet, it will turn around and eat its egg shell, which is directly in front of it.

Showy milkweed is closely related to common, has vigorous growth, but is not as invasive.  It, too, can grow to 5 feet tall, and also has long, thick hairy leaves.  My showy milkweed seemed to grow more horizontally than my common.  Below is a photo of a 2nd and a 5th instar caterpillar on showy milkweed.

Here are the 6 showy milkweed in my research plot on July 30th.