For Jack's Classic Bloom, they recommend 1/4 tsp per gallon at each watering or 1/2 tsp per gallon every other week. I was using half the recommended dose (1/8 tsp per gallon) with every watering. The white widows are the ones that seem to dry out the fastest. The shade leaves really start to droop after two days and the soil is dry. These plants are about 8' tall now. I'll give your method a try.