Whats wrong with my Asclepias incarnata?

It looks like the stems are being cut off about 4" from the top. I removed the pieces that were cut and it happened again. The leaves are also turning black.

Another picture.

bump....anyone know?

Not me. I don't know about the cut ends, but the black looks cultural. Like cold damage, maybe. Have any chemicals been used on it?

No chemicals and it was late to get started so I don't think it was exposed to cold. How cold is too cold?

Oh I wanted to add that all the plants surrounding this one are perfectly healthy. I did use bought loam that I used to fill in almost one whole side of this area, so that could have something in it I am unaware of. It was sold to me as composted loam and was recommended for gardens. If it is from that, it's just odd that no other plants are having the problem even other Asclepias.

I just don't know, but I'd give it some time. Maybe it will grow out of it.

I am wondering if Swamp Milkweed Beetles are the culprits? I have found very little description of what they do to the plants.

They eat them. You would have ragged leaves with lots of holes. And you would see them on the plant.

Do they cut stems I wonder? I have seen them on other milkweeds, and last year when I started seeing them on the milkweed the leaves did turn black. Maybe they are causing just the black leaves.

I can't see how they would cause black leaves.

Milkweed gets three serious pests: milkweed beetles that eat the leaves, milkweed bugs that suck the juice from the leaves, and aphids that suck the juice period. The fourth is not considered a pest - the larva (caterpillar) of the monarch butterfly, that also eats the leaves. The fourth is the reason we don't dare use pesticides on milkweed.

As I said before, I would just wait and see if it grows out of it.

Black leaves are usually a cultural problem not an insect, could be too much water, or water splashing on the leaves when it rains or when you water, things like that. I suspect it's completely unrelated to the broken stems.

Now I noticed a couple black leaves on a nearby Monarda. It could be the water splashing on the leaves but I don't think it's too much water. My soil is sandy and we haven't had much rain. We finally got some well needed rain the last couple days. I found a thread that mention plants can get something from being transplanted. I am wondering if this is the problem because the Monarda and the Swamp Milkweed were both transplanted in fall. Oh and mixed with cutworms, I just found it odd that they'd choose the milkweed over all the other plants in that garden. There is a lot of variety because it's in my butterfly garden and the Swamp milkweed is the only one cut.

Cutworms eat the plant off at the base.

Yellowing of the leaves, starting at the bottom of the plant, is the usual symptom for over-watering.

Black leaves usually indicates cold weather damage.

Another option is some kind of nutritional deficiency. Or chemical damage. But it still looks like cold damage to me.

I do not believe it is fungal, bacterial, viral, or insect related.

Is there a bar-b-que cooker nearby? I just remembered what some plants looked like that got too close to a heat source. The tops wilted and the edges of some of the leaves did too. The tops didn't bounce back.