I started to look this up when I realized that I cut my Spicebush back all the time and during any time that I am raising SBST. So go ahead and trim. But, be careful not to trim berries. If you can pick those when they are red, you can grow more trees from seed. Small 4" pots, put in the seed at least an inch deep. Place pots in one of those open weave trays. Cover the top with another open weave tray. Duck tape to keep the critters out. By next spring you will have new little trees. Thanks to Carol Ivory a master gardener in Reston for this neat tip.

I have two that are growing in full sun, so at least this far north it is happy in full sun. I have seen one growing wild in northern Ohio (where I grew up) under high trees on a stream bank (above most flooding, but maybe rare high water.) So it was probably in all day (or almost) shade there. The shaded one was less densely branched than mine, but it was blooming just fine. If your shade is relatively bright, I would imagine that it will be happy there. Here is one of mine just starting to bloom last spring. Since it is fine is a range of sun exposures, and the pH range from NH to OH is from quite acid to slightly basic, I think this shrub is fairly flexible about growing conditions, though I don't think it likes it too dry.

I use bonide as well. Actually just did my first application with it this weekend. I too applied to little, but in spots around my driveway and walkway (where I was trying to be careful not to get on the concrete), I actually saw the grass turn almost to a black color. I went back and re-read the directions and I did not apply enough to the whole yard. 1 gallon covers only 1k sq ft. My front yard is around 8600 sq ft and I only applied 4 gallons. I am going to start a new thread that show results of the applications, but here is a few pics of what I saw after a day or 2. Note for reason the grass isn't as green as it should be: 1) it is common Bermuda-seeded 2 years ago. 2) Haven't fertilized in over a month due to the rain 3) cut it very short last week to get back to the height I wanted the grass at. Cut 2 days apart and 2nd cut too over a little more than 1/3 of the blade. 4) I also am dealing with bumpy yard and uneven cut from my mower, which currently working on to improve.

I didn't think you could use a dremel or anything like that on a reel mower. I thought that would leave the reels with high and low spots. I have seen mclanes and/or John deeres for 200-400on craigslist. That caught my interest but if I am going to have to pay 100 or so a season to put the reel on a relief grinder which is what I thought had to be done, I am not interested. I'll have to look into a growth regulator. @reeljake, the rotary is cool but I definitely scalp the yard in places. I don't want to raise it up too high after having it so low with the reel mower if that makes sense. Where I messed up is I did raise the cutting deck on the rotary when I couldn't cut it with the reel. What I should have done was left the rotary at a low height and just cut it and if the grass browned, oh well. I could have put down some iron to green it back up and resumed cutting it with the reel.