It's been a dry summer and I haven't been able to make an application of roundup to the buckthorn stump regrowth since early June. We've had at least 2 hard frosts (mid 20's) already and about 3 or 4 nights in the low 30's, but its supposed to get up into the 60's next week. Will this be a good opportunity to make an application or is it too late in the season? The buckthorns have all put on some new growth since the good soaking in early September, and appear unaffected by the frosts. Thanks.