I always supplement my home grown with wild common (washed of course). The large leaves of the common go a long way when they reach 4th and 5th. Even now this early, I go out every week and collect about 100 leaves. I always take a leaf that has a shoot coming off of the stem. THat way, within a few days, there's another branch forming with tender foliage that will be attractive to egg laying females. Taking one or two leaves from a healthy plant causes the plant to put forth more healthy and green leaves and is actually beneficial for the monarchs.