I am growing Quinalt Strawberries (only type I found at Lowe's). They are planted in a"City Pickers" box. Following the directions for the box, I added Osmocote Flower and Veg Plant Food and Dolomite Lime when preparing the soil. The soil tests to a 5pH. So far, the plants haven't grown much in several weeks and the few berries are tiny and lumpy. What do I need to do to improve these plants? They are getting lots of light.