Q: I have been impatiently waiting to fertilize until my zoysia grass has greened 75-100 percent. Why must I do this, other than because you say so?
A: You’re a smart person to always be asking “Why?” in the garden. The reason to delay zoysia fertilization is that it can’t use fertilizer until it has an active root system. It won’t have an active root system until it has green shoot growth AND soil temperatures are above 65 degrees. Because zoysia doesn’t have a lot of stored reserves from winter, all it takes to severely weaken it is an early fertilization combined with a late freeze. The easiest way to describe when conditions are right for feeding zoysia is to say “Wait until it is 75% – 100% green.”. That’s when you know the grass can use fertilizer appropriately.