Fall is the broadest planting window
October through early December is often ideal for native trees, shrubs, grasses, and perennials. Soil remains warm enough for root growth while shorter days reduce water loss. Plants then have winter and spring to establish before June.
Watch the forecast rather than the calendar alone. Delay planting during an unusual heat spell, and protect frost-tender species in colder Valley locations.
Spring can work—with less margin
Late February through March can be successful, especially for heat-loving plants, but the establishment runway is short. A plant installed in April may face triple-digit temperatures before it has built a useful root system.
If planting in spring, choose healthy stock, irrigate the full root ball and surrounding soil, and check moisture frequently during the first summer.
Special cases: monsoon, cacti, and frost
Summer monsoon humidity can help some warm-season plants, but planting during extreme heat is stressful for both plants and people. Container-grown cacti and succulents are vulnerable to rot when disturbed just before repeated storms.
Cold-sensitive plants are best installed after frost risk declines, while hardy desert trees often benefit from fall planting. Avoid planting into saturated soil and never leave a dry nursery root ball surrounded by wet native soil.
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General educational information only. Site conditions and plant needs vary; consult local professionals when necessary.