We have a separate butterfly garden in our backyard here in Houston. One problem, however, is that most of the milkweed we can get is not native to Houston, meaning that it grows longer than it should. This causes the butterflies to stay too long and can actually be detrimental to the population. We have started to cut down the milkweed at the appropriate time, so that we can encourage them to move on to Mexico. Fortunately, we don't yet have a wall that keep butterflies from migrating south.