Virginia buttonweed <BR>Seed germination <BR>       - optimum at 85 to 95 F. <BR>       - no germination < 70 F. <BR>       - optimum depth 1.0 to 1.5 inches <BR>Shoot emergence <BR>       - root fragments 0.25 inch long can    <BR>         produce shoots from 8 inch soil depth<BR>