I have started giving out my plants (some have Monarch eggs and/or caterpillars already on them) so my community will be ready for both the Fall and Spring migrations of the Monarchs. I have learned it is important to understand that the California native milkweed should be used in larger restoration projects to try and avoid problems with tropical milkweed giving butterflies the parasite called “OE.” If tropical milkweed is used I have learned from the CalPoly Monarch research project that it must be cut back to 2-4″ from October to February to avoid the spread of the Oe parasite that is plaguing Monarch Butterflies (especially those involved in the Eastern United States migration). The spread of Oe may be directly related to the use of Tropical Milkweed. Researchers are working hard to understand the relationship between the widespread use of Tropical Milkweed and the increase in Monarch Butterflies affected by Oe. Oe is very bad for Monarchs. It weakens the butterfly’s flight muscles which makes them unable to complete their migrations. It is always best to plant native milkweed because its lifecycle is in tune with the lifecycle of the monarch migration. Tropical varieties do not die back because they are a perennial and this allows Oe to accumulate on the plant’s leaves all year round and spreads the parasite more effectively.