What to Plant in Arizona in August
Most of Arizona has no real frost calendar in August, and that’s precisely what makes the month tricky.
Home & garden, state by state
Everything we have worked out for Arizona: what to plant and when, which varieties finish in time, the pests that actually turn up here, and the jobs that pay off month by month. We also cover the rest of the property, from lawns and soil to home care and energy, because a garden rarely stops at the vegetable bed.
The numbers first, because everything else follows from them. Measured at the weather station in Phoenix, the last spring freeze falls around no freeze in most years; a rare cold snap can bring 32F between late December and mid January and the first fall freeze falls around no reliable fall freeze; see the note, USDA zones 4b-10b, 8,014 growing degree days in the year.
Heat, not frost, is what shortens the season here: above 86 °F tomato pollen goes sterile, so growers run a spring crop and an autumn one rather than a single long season. Garlic is the awkward one: only 0 weeks below 40 °F, where it needs six to split into cloves. Chill the cloves before planting, or grow a softneck type.
Elsewhere on the property in Arizona: the pests that turn up here.
Figures from NOAA's 1991-2020 climate normals. A state is not one climate: elevation, a large lake or the coast can move these dates by two weeks either way, so check your own county with the extension service before you spend money.
Most of Arizona has no real frost calendar in August, and that’s precisely what makes the month tricky.
In low-desert Arizona (Phoenix, Tucson, Yuma), April belongs to warm-season crops: beans, squash, melons, corn and okra go straight into the ground, and…
Arizona’s low desert calls for fall planting, not spring. At 33.43 degrees north, Phoenix gets 14 hours and 13 minutes of daylight on the summer…
Low-desert Arizona rarely delivers the sustained chill spring bulbs need to bloom on their own, which is exactly why forcing works here: you supply the…
Phoenix winters average a coldest-month low of 45.3°F, according to NOAA climate normals covering 1991-2020.
Heating demand in the Phoenix area doesn’t show up until December, and even then it’s mild by national standards, peaking that same month and fading out…
In low-desert Arizona, the deciding number isn’t the last frost date. It’s the count of days the soil bakes past 90 F, and at the reference station in…
Whether canning at your elevation in Arizona needs an altitude adjustment depends entirely on where you live, not on the state as a whole.
Arizona sits at a latitude where short-day and intermediate-day onions bulb reliably, while long-day onions never will.
Arizona’s watering rules aren’t one-size-fits-all: a garden bed in Phoenix behaves nothing like one in Flagstaff, and the USDA Plant Hardiness Zone Map…