If you have overgrown shrubs in your yard that are just way too big, the ideal time to cut them back is when they are dormant.
The safest way to take a large overgrown shrub and cut it back considerably is to decide exactly what height you desire the plant to be, then cut just one third of the branches to that height. Then the next year do another one third, and then finally on the third year cut the final one third to the height you desire.
If you don’t want to take any chances with your plant, that’s the ideal way to cut it way back. But that’s not always practical and when I was in the landscaping business I had people hire to me to take an entire hedge and cut it way back. Of course I explained to them that it could be stressful on the plants, but they said they didn’t care, they wanted it cut back now. So that’s what I did. Every time I did that the hedge grew back beautifully.
I’ve taken Burning Bush hedges that we’re 12′ tall and cut them back to 30″. Nothing left but heavy woody stubs. It takes at least two seasons, before the hedge starts to look normal again, but you should see those plants today!
I’ve taken large overgrown Rhododendrons and cut them right in half. In almost every case it reinvigorates the plants. Even a slow growing evergreen like Taxus Hicksi can be cut back really hard and they almost always come back really beautiful.
So I’ve given you the text book, safe way to severely cut back plants, and I’ve given you the radical approach. You decide which action you want to take.
Mike McGroarty is a Garden & Greenhouse contributing editor, the owner of McGroarty Enterprises and the author of several books. You can visit his website at Freeplants.com and read his blog at Mikesbackyardnursery.com.