Annuals and perennials:
An appropriate watering program would be an in-ground irrigation system with heads and watering schedule adjusted to cover all of the new plantings so that one inch of water per week is received. Proper adjustment depends on the water pressure at your home. You need to measure in order to get this right. Probe the ground with your fingers after watering to see that the ground is wet a good 6” or more in depth.
New trees and shrubs:
New trees and shrubs must be saturated daily for one week after planting, twice per week for the next month, and once per week for the remaining season. The irrigation system will not be adequate, and hoses must be used, if:
Lawn, shrubs and perennials are on the same irrigation zone. In this case adequate watering for shrubs or trees will swamp the lawn and perennials. Note: have your irrigation company put lawn and garden beds on separate zones.
New trees and shrubs share an irrigation zone with older established trees and shrubs. The older plants will be fine, but your water use will be higher than necessary. Hoses get the water to just the new shrubs and trees.
If the garden is entirely new and shrubs and trees have their own zone separate from lawn or perennials, then the irrigation system can be set to water the new material. Check to see that all plants are reached by the spray heads. If you see dry spots, adjust the heads or water by hand.
Watering schedule for the first year:
The rule of thumb is: water deeply every day for a week, twice per week for a month, and weekly for the rest of the season. Weekly deep watering is especially important in October and November in preparation for winter. Yes, keep that irrigation system running through October. Don’t winterize it too early!
Steady, generous water in the first growing season is the key to a healthy plant. Be consistent this season, don’t let the plants get stressed from lack of water, and they’ll grow beautifully in future years— with a much reduced watering schedule.
Cultivar will recommend plantings to suit natural growing conditions and offer suggestions for watering strategies, but cannot assume responsibility for watering clients’ gardens.