Install additional attic insulation at right angles to the previous layer. You don't have to use the same type of insulation - it's fine to use batts or blankets over loose-fill, or vice versa. Upgrading from three inches to 12 inches can cut heating costs by 20 percent, and cooling costs by 10 percent.
Water new shrubs once a week the first summer with 5 to l0 gallons of water for each depending on the size of the bush. Take care to get the water under any mulch, which absorbs a great deal of moisture and robs the soil below. Pour water right down the stems so it goes into the root ball, and does not run off on the ground. During very hot sunny days, spray the tops and water lightly in addition to the weekly deep watering. Do not fertilize the first year, except possibly for half strength liquid fertilizer at planting time, or plant rooting hormone additives one can use. Fertilize normally the second year in the spring.