Swamp Milkweed Leaves turning rust color

[schaumburg]

Some of the lower leaves of my swamp milkweed are already turning a rust color. What causes this? Is it a fungus, too much water, not enough water? I have had this problem in other years but is usually doesn't occur until later in the year. Is the cold wet spring here in Northern IL part of the problem?

[blazing star]

Hi Schaumburg,

I'm your neighbor! My office is actually there. My lower leaves are turning color and falling off, too. Im not sure what's causing it but it never seems to harm the plant. I think it may have something to do with energy input and output of the plant and as the plant gets taller, it simply may not need the lower leaves to produce energy. That's my assumption.

[Mona Miller]

http://monarchwatch.org/bring-back-the- ... -incarnata
"Foliage: ...The leaves on plants exposed to full sun are often purplish toward the end of the growing season.."

[GBMonarch]

I'm having the same thing here in Wisconsin. We have had so much rain & cold weather, I'm thinking that's part of it.

Like you, I usually don't see the discoloration till the fall.

Here's hoping we get some sun soon.

[Mona Miller]

Some of my swamp milkweed has already bloomed and the leaves are a purplish color. Crazy weather.