Consider automated irrigation. Drip tube systems, while requiring back breaking work to set up, save on labor costs, maximize water use and promote crop uniformity. Given, over supply, of fall mums, and relatively low retail prices,in many areas, growers must maximize production efficiencies. Hand watering mums during hot, dry summer conditions is labor intensive, increases production costs and jeopardizes profitability. Once roots are developed, they benefit from relatively high rates of fertilizers compared to most spring garden crops.
Growers fertilize in several ways and each can produce good results.
First, container mums, in artificial media, may be grown entirely with slow release fertilizers incorporated, into the mix, prior to planting. Carefully read and follow product directions regarding rates and duration of nutrient release. Another option is incorporation of lower rates of slow release fertilizers and supplementation with liquid fertilizers. Finally, it is possible to use exclusively liquid fertilizers at rates between 200 to 300 ppm of nitrogen during each irrigation. Finally, be aware of your water quality.