Q.Watering Mums
Following advice to water each plant with 1″ of water – how would I measure that 1″?

Adding an inch of water applies only when there has been less than an inch of rain. If there has been rain in the preceding week, subtract that amount from 1.0 inches. An inch equals 16 gallons per square foot which is a lot. If using a sprinkler or soaker hose, sink a tuna or pet food can with straight sides until it is level with the garden soil. Time how long it takes to reach one inch; this may be several hours by soaker hose. As temps cool and days shorten, the plant needs less water. The soil should be dry down 1.5-2 inches before the next watering. Weekly is an average. Temps over 85, sandy soil, large plants and windy weather increase the need for water. If your soil is heavy clay, it will hold water longer than loam or sandy soil. Certainly, the soil should not be mucky or wet. Damp soil is what you are after. By watering heavily once a week or so, you encourage the roots to go deeper into the soil; this is important for long-term survival. If your plant is in a container, water when the top 1 inch of soil is dry. The one inch recommendation is for plants in the ground in average soil.