I don't know about the roots, but mine is around 12 high planted next to our driveway. A lot of mornings I wake up and it looks like it snowed on my car. That might be a problem with your pool water/filter........cheryl

Blessed mother, I don't see there would be and need to cut them back until they get too tall. They bush out on their own mostly from the roots. BTW, Schumachers had about a flat and a half of four inch Sweet Almond Verbenas. I saw two in gal. pots. Tally, sorry you lost yours. I'll see if I can root some for you.

Hello okokok. My friend gave me AV about 2 years ago. It was in 5 gallon pot and about 1 ft tall with a big root ball. I planted about 1.5 years ago, and now it is about 6ft tall. AV blooms in rapid cycle and have very strong vanila fragrance very non-showy flowers. I am so glad that my friend gave it to me. To answer your question, I only trim/shape my AV, and do not trim down to the ground. I do not think it will grow to about 10 to 15 ft in height in 1 season, and I have never heard of it for AV. You can leave it to be like a bush, or you can trim to kinda look like crape myrtle (bottom thin, top heavy). Happy Gardening,

Wasps and bees all sated and happy on a flower won't bother me. Mine act like they are drunk or something.