Do primroses grow tall and will some kind of support help them grow taller?
Certified GKH Gardening Expert
These plants do get somewhat tall but unless they are falling over, it's not necessary to support them. If you would like to stake them, however, it will not hurt to do so. As far as this helping them to grow taller, plant supports have nothing to do with that. An abundance of nitrogen fertilizer will cause lush growth, though too much will inhibit blooming. I would stick with either a balanced fertilizer or one higher in phosphorus.