October 2026 Newsletter

October yard work is easier when you separate two questions: who supplies your irrigation water, and where a new tree or shrub will actually thrive.

First, check your irrigation provider—not just your city

There is no single irrigation shutdown date for the whole Treasure Valley. Your provider and the system serving your property control the schedule.^[3] The Boise Project Board of Control’s notice, checked September 28, said deliveries to lands supplied by its Arrowrock Division and Lake Lowell reservoir were scheduled to cease Monday, September 28, 2026.^[1] The notice does not confirm whether deliveries actually stopped, and its schedule applies only to those provider-served lands—not every valley home.

Start with the provider named on your irrigation assessment or bill, then check its latest notice and follow its instructions for your system. Our 2026 shutdown-date guide and irrigation-district guide help you find the right source. Don’t use a neighbor’s date or a general checklist as a substitute for your provider’s directions.^[3]

Then, plan a planting site—not just a shopping list

University of Idaho Extension identifies early spring and early fall as preferred times to plant trees and shrubs, when shoot growth is minimal and roots have time to establish. Container and balled-and-burlapped plants can be planted when the soil is not frozen; early spring and early fall are still preferred windows.^[2]

Before you choose a plant, check its mature height and spread, the site’s sunlight and moisture, and possible conflicts with utilities or local planting rules.^[2] Our fall planting guide and Treasure Valley tree guide are good starting points; match the final choice to your own lot.

Three useful steps this month

1. Find the irrigation provider for your property and read its latest notice.^[3]
2. Follow that provider’s winterization directions; use our winterization checklist as a planning aid, not system-specific instructions.^[3]
3. Pick a planting location and check mature size, sun, water needs, and nearby utilities before buying.^[2]

Landscaping the Treasure Valley is an independent homeowner’s field guide—not a landscaping contractor. Local irrigation schedules and rules vary by provider and city.^[3]

Sources

1. Boise Project Board of Control, public announcement. Checked September 28, 2026. The announced schedule applies to the named Arrowrock Division and Lake Lowell service areas; it is not a valley-wide declaration.
2. University of Idaho Extension, “Trees, shrubs and vines”. Guidance on planting windows and selecting a site.
3. Treasure Valley irrigation shutdown dates. Updated September 28, 2026; use this guide to locate provider notices, then verify the current instructions with your provider.