How do aphids move around? Does some stage of them fly? All my hems are in containers, but they are kept outdoors here and thus subject to the cold temps. It's been mild this year. The coldest night here has only reached down to 22F by my thermometer and so far all daytime temps have remained above freezing. Compared to last year when it set a record by falling below zeroF. Usually winters here have some days that don't get above freezing, but not many. Not all the hems have visible infestations of aphids. Probably only about 20-30% of those where the growth is up enough to really tell. Because we had another cold front move in, I haven't done anything. However, I did pull off the old leaves and clear off the accumulated oak leaves from a couple and they are continuing to grow in spite of some more temp drops. Neither of those show any sign of aphids - yet.
