I had my brug planted in the ground all spring- summer but it is time to dig it up and bring it in soon. It grew quite a bit and needs to be pruned back so it will fit inside. Below is a diagram of what my brug looks like. If I cut at the red lines it will be manageable. However, I was wondering if it would be better to cut at the purple lines. Any advice would be appreciated.
I recommend cutting on along the red lines. It's extra insurance against die-back which can easily happen under cool moist conditions. Be sure to spray all cut surfaces with a fungicide, another insurance against die-back which can kill an entire branch or plant.
'Been growing these beauties for over 20 years and the pruning depends on what shape you want when it starts growing again next summer. I see you are in Chicago. I'm in Cleveland so I deal with this every year. Have over 30 brugs.
If you want a shorter bushier plant you could prune all the way back to the soil level. I'm not kidding. Next heat you would get multiple shoots coming up at once. If you like the basic branch structure the plant already has then just decide much branching you want to keep. Next year multiple new shoots will apprear all up and down the branches that remain even at the soil level. This is a plant that has adventitious buds under it's skin everywhere. This is great because there is not special location to make your cuts except if you want to keep the branch(s) as the plant's base structure.