I plant about 145 lavender plants in November last year. Today, I have 100 absolutely beautiful and 45 that are not growing at all. They are green but the same size that I planted them or even smaller. They all got the same exact treatment since day one.
Certified GKH Gardening Expert
Environmental conditions can effect your plants and the growing rates and patterns can and will deviate from plant to plant.
I have listed a few links for you.