"I was thinking cut back now, fertilize and then cut back again next January/February and fertilize. So when March 2020 (beginning of Monarch time in central FL) comes the plants would have a lower amount of OE."

Exactly right! You can cut MW back any time. Mine looks beautiful now - it sure didn't look that way when the aphids were on it!

Sherry

What is OE, please?

Ophryocystis elektroscirrha. OE is a protozoan parasite that caterpillars ingest on milkweed. It is spread through microscopic spores coming off the wings and bodies of adult butterflies. It is devastating to Monarchs. And most prevalent in Florida where milkweed doesn't die back.

I think It effects about 70% of Monarchs in Central and Southern Florida to varying degrees. Some die in the chrysalis. Some emerge so deformed they cannot fly. Some emerge sluggish but can fly. These shred the protozoa to every leaf they touch and every egg they lay.

OE is the big reason for all the discussion about "bleaching" milkweed leaves and monarch eggs. When OE are in the spore form they are pretty much bullet proof accept for contact with bleach. Most people use a 5% solution by volume with 1 minute contact for leaves and eggs.

So cutting back milkweed at the right time can cut down on the leaves exposure to OE carrying butterflies. I found out the hard way not to allow Monarchs to eat milkweed in March grown over the winter here in Florida. But even if you cut back and feed only newly sprouted leaves, if you are in FL, you should still start with eggs, bleach them and bleach the leaves you will be feeding them when they hatch. That's the only way to make sure you will raise healthy Monarchs

There are lots of great articles and videos on the web on how to eradicate OE from your Monarch raising system. As far as I know there is no way to eradicate it from the garden.

Anna