Okay, since no one answered, I'll tell you that view, I did it anyway! It was the best thing I could've done to save the large Aralia and other big plants in the garden! It was too thick and leaves were on the ground simply because it was too crowded! The flowers were finished blooming, so I too them all down to two inches. Since summer hasn't hit, I figure they'll have plenty of time to grow the leaves again. And in the meantime, I've saved the rest of my plants! I had such a bad infestation that I've sprayed once and am about to do it again, wait another week and do it again! These dang flies are relentless! One spray will not kill everything! You MUST saturate the underside of each leaf, the ground, the top, I even sprayed the garage wall that they're up against, the hose and where I store it because some had been trying to land there! Make sure to cover EVERYTHING! I've never seen the likes of this infestation! So be brave and do it, if you have to! It's not fun, hard work, and disappointing! Just be sure that when you're done to take all your clothes and shoes off outside and get to the shower immediately! Unfortunately, taking these drastic measures, I did, despite wearing gloves, get the spray on my arms! Get covered! Also, I did this in the cool of last light in the evening. I bagged EVERYTHING in sprayed garbage bags, sealed and took them to the dump. Be sure you do not interact with other plants outside or inside before showering! Therefore, the suggestion to take all clothing and shoes off outside until you can wash them in hot water! Even one escapee can and will make your life miserable! So, that's what I did, and suggest. I'm NOT a professional at anything, so take it or leave it. I wish you the best of luck with whatever you decide to do! It can get ugly out there! ;-). Joey