You can use FoxFarm Grow Big Liquid Plant Food 6-4-4 on new plantings as long as they have been able to settle for a few days. You would apply at every other watering as a soil treatment. FoxFarm also has a wide variety of Feeding Schedules on their website to assist you.
FoxFarm Grow Big Liquid Plant Food 6-4-4 rates for every watering 1 teaspoon per gallon, for heavy feeding 2-3 teaspoons per gallon every two weeks and for foliar feeding 1/2-1 teaspoon per gallon. Use a pump sprayer and apply to both sides of leaves. Early mornings are best.
The FoxFarm Grow Big Liquid Plant Food 6-4-4 is not designed for large area applications or for fertilizing fields, which is why there are not use instructions for this purpose. It's designed for smaller application areas and specifically geared towards the needs of vegetables. house plants in containers, and shrubs on a property.