Q. I’ve been thinking about growing milkweed plants to help in the Monarch fight. Two varieties look worth pursuing Asclepias EROSA and SUBULATA. Any thoughts? A. I grew up in the Midwest and in the path of Monarch butterflies migration routes to Mexico. In fact, as a boy I volunteered to monitor Monarch butterflies for a research study done in Canada back in the 1960’s. After moving to southern Nevada I have not seen any Monarch butterflies in the 30 years I’ve been here in the Las Vegas Valley. My understanding is there are two migration routes; one from the eastern population of Monarch butterflies and one from the Western population. Map of Monarch butterfly routes http://en.wikipedia.org/wiki/Monarch_butterfly_migration#mediaviewer/File:MonarchWanderungKlein.gif The eastern population misses us completely in the Western population is pretty much restricted from us by the Sierra Nevada Mountains. Encourage and sustain local populations. I agree with you wholeheartedly on encouraging our local populations of butterflies and moths. They had a lot of beauty and grace to our landscape and provide some pollination and a food supply. Instead of focusing just on milkweeds I think a diversity of plant material for attracting these insects might be important. Be careful of pesticide use. Also, reducing or eliminating pesticide use in the butterfly garden area would be wise. There are a number of pesticides that are harmful including two that I recommend frequently to organic gardeners: Bt and Spinosad. When considering pollinators both of these insecticides can be lethal, in particular Spinosad to bees. Always apply pesticides, if they must be applied, at times when these creatures are not active. This means the very early morning hours. Many of our moths fly at night so I would avoid applying pesticides at dusk if a major concern are night flying moths. Further reading. I put together some links on general information on Monarch butterflies, moths and butterflies of southern Nevada and how to make a butterfly garden. I wish you much success. Wikipedia on Monarch butterflies http://en.wikipedia.org/wiki/Monarch_butterfly_migration Donate to Wikipedia http://wikimediafoundation.org/wiki/Ways_to_Give  Threats to Monarch butterflies http://www.flightofthebutterflies.com/conservation-preservation/ Butterflies of southern Nevada. http://www.unce.unr.edu/publications/files/ho/2005/sp0525.pdf How to make a butterfly garden in the southwestern desert of the US http://www.dbg.org/system/files/253/original/Butterfly%20Gardens%208-11.pdf?1315954953 http://gardenoracle.com/butterfly_garden.html