Low Desert Almanac

Planting Calendar

What to sow, transplant and harvest in each month of the Phoenix gardening year, for the Valley’s two growing seasons, from University of Arizona Extension guidance.

Yard & Garden

What can I plant this month?

Pick a month

The two seasons

Cool season

October through April

The main season, and the one people moving here do not expect. Lettuce, carrots, broccoli, peas, spinach and everything else that bolts or turns bitter in heat does its whole life in this window.

Warm season

February through November, with a gap in high summer

Tomatoes, peppers, squash, melons, beans, corn and okra. It is not one run: most warm-season crops are sown in February and March, and several of them are sown a second time in July and August for an autumn crop.

Every window on this page comes from AZ1005, the University of Arizona co-operative extension’s Vegetable Planting Calendar for Maricopa County. The herb windows come from the same extension’s low-desert herb guidance.

October

The cool season opens

October is the month the Valley’s main growing season begins, and the busiest planting month of the year.

    Vegetables and everything else

    Every crop on the county calendar, with the month each one goes in the ground. S is seed sown where it will grow, T is a transplant set out, and X is sets, cloves or slips. The harvest column is the publication’s days from planting to picking.

    Crop by month, AZ1005. The selected month’s column is marked.
    Crop JanFebMarAprMayJunJulAugSepOctNovDec Harvest
    Artichoke, Globe Vegetable T T T S S 4–6 months
    Artichoke, Jerusalem Vegetable T T T T T 6–8 months
    Asparagus Vegetable T T T 2–3 years
    Beans, Lima Legume S S 60–100 days
    Beans, Snap Legume S S S S 60–90 days
    Beans, Yardlong Legume S S S S 60–90 days
    Beets Root S S S S S S S 60–80 days
    Black-eyed Peas Legume S S S S 90–120 days
    Bok Choy Salad S S S S S S S 45 days
    Borage Vegetable S S S S S 50–80 days
    Broccoli Vegetable S T S S T S T S T S T 90–130 days
    Brussels Sprouts Vegetable S T T T 100–150 days
    Cabbage Vegetable S T S S T S T S T S T 80–130 days
    Carrots Root S S S S S S S S S 60–100 days
    Cauliflower Vegetable S T S S T S T S T S T 90–130 days
    Celery Vegetable S S T S T S T S T 120–150 days
    Chard Salad S T S S T S T S T S T 60–90 days
    Collard Greens Salad S S S S S S 80 days
    Corn, Sweet Vegetable S S S S S 70–90 days
    Cucumbers Vegetable S S S S S S 60–90 days
    Eggplant Vegetable T 70–120 days
    Endive Salad S S S S S 80–120 days
    Garlic Root X 5–7 months
    Kale Salad S S S S S 60–90 days
    Kohlrabi Vegetable S T T S S S T S T S T 45–60 days
    Lettuce, Head Salad S T S T S S T S T S T S T 50–100 days
    Lettuce, Leaf Salad S T S T T S S T S T S T S T 30–90 days
    Melons, Cantaloupe Melon S S S S S S 80–120 days
    Melons, Watermelon Melon S S 90–120 days
    Mustard Salad S S S S S S S 35–45 days
    Okra Vegetable S S S S 70–100 days
    Onions, Bulb Root X X S S X 4–8 months
    Onions, Green Vegetable S S S S S S S S S 90–100 days
    Onions, Shallots Root X 80–110 days
    Parsnips Root S S S 100–120 days
    Peanuts Legume S S 5 months
    Peas Legume S S S S S 60–150 days
    Peppers Vegetable T T T 90–120 days
    Potatoes Root S S S 90–120 days
    Potatoes, Sweet Root T T T T 120–160 days
    Pumpkin Melon S S S 90–120 days
    Radishes Root S S S S S S S S 30–60 days
    Rutabagas Root S S S S S 100–120 days
    Spinach Salad S S S S S S 30–90 days
    Squash, Summer Vegetable S S S S S 60–90 days
    Squash, Winter Vegetable S S S 90–120 days
    Sunflower Vegetable S S S S S S 90–110 days
    Tomatoes Vegetable T T T 50–120 days
    Turnips Root S S S S S S 75–120 days

    Herbs

    Herbs by the season the extension’s low-desert guidance puts them in. The publication gives seasons rather than single months, so the windows are named as it gives them. A frost note means the publication flags that herb for protection on a cold night.

    Herbs by season window.
    Herb Grown as Planting windows Frost
    Basil Good first herb Warm-season annual February–April · May–June None
    Borage Cool-season annual October–November · February–April None
    Chamomile Cool-season annual October–November · February–April None
    Chervil Cool-season annual October–November None
    Cilantro Good first herb Cool-season annual October–November · February–April Protect
    Dill Good first herb Cool-season annual October–November · February–April Protect
    Fennel Good first herb Cool-season annual October–November · February–April Protect
    Parsley Good first herb Cool-season annual October–November · February–April Protect
    Summer Savory Warm-season annual April–June None
    Chives Good first herb Cool-season perennial October–November · February–April None
    Garlic Chives Good first herb Cool-season perennial October–November · February–April None
    Lavender Good first herb Cool-season perennial October–November · February–April Protect
    Lemon Balm Cool-season perennial October–November · February–April None
    Marjoram Good first herb Cool-season perennial October–November · February–April None
    Mint Good first herb Cool-season perennial October–November · February–April None
    Oregano Good first herb Cool-season perennial October–November · February–April Protect
    Rosemary Good first herb Cool-season perennial February–April None
    Sage Good first herb Cool-season perennial October–November · February–April None
    Thyme Good first herb Cool-season perennial October–November · February–April None
    Lemon Grass Good first herb Warm-season perennial April–June None
    Lemon Verbena Warm-season perennial April–June None
    Mexican Tarragon Warm-season perennial April–June None

    Soil temperature. 65–85 °F for most common vegetables. Below that, seed rots rather than germinates; above it, germination drops off and seedlings stretch.

    Figure from University of Arizona Cooperative Extension, AZ1005 .

    How this works

    Method

    The calendar is upside down, and that is the whole point

    Almost everyone who moves to the Valley brings a growing calendar from somewhere else, and almost everyone plants by it for one season before the penny drops. The calendar they brought has spring as the beginning of things. Here, spring is the end of things. The Valley’s main growing season opens in October, runs through the mild winter and closes in April as the heat comes on; the second season runs from late winter into early summer for the crops that want heat, and then a third overlap in late summer carries the warm-season crops into an autumn harvest. Lettuce, carrots, broccoli, spinach, peas and everything else that turns bitter or bolts the moment it is warm does its entire life between October and April. Tomatoes, peppers, squash, melons, beans and okra want the heat and will not do much until the soil is warm.

    The county’s own planting calendar (AZ1005, from the University of Arizona co-operative extension’s Maricopa County office) is a half-month table that carries both seasons side by side, which is what makes it worth reading rather than any generic “when to plant” guide. The table on this page is that calendar laid out as a year you can read across. Plant into a season’s window and the crop is working with the weather; plant against it and you spend the season fighting a soil temperature you cannot change.

    Two seasons, overlapping, and a gap in the middle

    The cool season runs October through April and the warm season February through November, which means the year does not split cleanly down the middle. The two overlap through spring and autumn, and that overlap is where the best growing of the year happens. A bed can carry a warm-season crop and a cool-season crop in the same twelve months if you plan the hand-over: tomatoes out and a second sowing of beans in, or a lettuce bed pulled and squash sown into the space in March. The overlap is also where the second plantings live. Beans, squash, cucumbers, corn and tomatoes all have a window in late summer as well as in spring, and the autumn crop comes off the second one.

    What the year also has is a gap. For a few weeks either side of the summer solstice, the soil is simply too hot for most seed to germinate and any seedling is up against 115 °F afternoons with a root system that cannot yet reach deep moisture. The county calendar thins out there for a reason. The crops that carry through it are the ones already established, and the planting that fills it is the one sown just before or just after.

    Reading the markers, and what a window is not

    Three markers sit in the grid because there are three ways to start a crop, and they are not interchangeable. S is seed sown where the plant will grow. T is a transplant (a seedling raised indoors or bought) set out weeks after a sowing would have been. X covers the crops grown from sets, cloves or slips rather than seed at all: garlic from cloves in October, bulb onions from sets through the winter, shallots in July. A crop with only one of those filled is one the publication expects to be started that one way, and a crop with two windows that look similar is usually one where the calendar is giving you both a sowing date and a transplanting date for the same result.

    The thing to hold on to is that a window is a time to try, not a guarantee. These are averages. A December frost that runs deep will take a cool-season bed that the calendar said was fine, and an early heat spike in March will finish a lettuce planting weeks before the table suggests. The windows tell you when the odds are with you; the frost article and the heat guidance are what you read when they are not.

    Why herbs get their own table

    Herbs are in the same year but not the same rhythm. Some are cool-season annuals that behave like lettuce and want the winter; some are warm-season annuals that want the heat and die at the first frost; and a large group are perennials that come back year after year and are simply divided or replanted in spring and autumn. The low-desert herb guidance the extension publishes gives them as seasons rather than single months, so this page names the seasons it gives instead of forcing them onto a grid. Cilantro, dill, parsley and fennel are the cool-season annuals, and they are the ones the publication flags for frost; basil is the warm-season annual that sulks below 50 °F; rosemary, thyme, oregano, sage and chives are the perennials that will still be there in three years.

    Read the two tables together and a Valley kitchen garden starts to write itself: cool-season greens and roots from October, warm-season fruiting crops from March, a second sowing of both in late summer, and the perennial herbs sitting through all of it. The month chips on the left are the fastest way in: pick the month you are actually standing in and read what the county calendar puts in the ground.

    Sources

    Where this came from

    Every figure this tool uses was read from the source named above on 11 October 2026. Anything still waiting on a check is listed in the site's data notes rather than shown here as if it were settled.

    Limits and assumptions

    Read this

    Before you rely on this

    This tool works from climate normals and published guidance, not from live weather. It describes a typical day for the month or date you chose, which is useful for planning and useless as a forecast.

    • The windows are stored to the whole month, and the publication gives them to the half-month. A sowing window that runs from mid-January to mid-March therefore shows against January, February and March, so the first and last months of a window are shown slightly early rather than slightly late. If a date matters to a particular crop, open AZ1005 itself rather than reading the grid.
    • This is Maricopa County’s calendar for the low desert. It is not the calendar for Prescott, Flagstaff or Tucson. Those places have their own elevations and their own frost dates, and the same crop goes in weeks or months apart.
    • A planting window is not a promise about the weather. The county’s dates are averages, and a hard December frost or a heat spell in early March will move what actually survives in a given bed. The windows say when to try, not when it is safe.
    • The herbs are stored by the season the publication puts them in, not by invented month numbers. The herb publication prints growing seasons and does not line every herb up against a calendar in a way that could be read to a single month with any confidence, so the herb table names the windows rather than guessing at dates the source does not give.
    • Days to harvest are the publication’s figures and describe a normal planting in a normal year. They count from the day seed goes in or a transplant goes out, they vary with the variety, and they stretch through the cold and shorten through the heat.
    • The table lists what the county calendar lists. It is not every edible thing that grows in Arizona, and a crop’s absence here does not mean it cannot be grown, only that it is not on this particular county table.
    • Sowing and transplanting are not interchangeable and the marker says which is which. A crop marked for transplanting at a given date is meant to have been started earlier, indoors or in a nursery bed, and a crop with no transplanting window is one the publication expects to be direct-sown.
    • The grid shows the month a crop is put in the ground, which is not the month it is harvested. A crop sown in September and harvested over three months from December will show markers only in the month the seed went in.

    Questions

    Short answers
    Everyone says to plant tomatoes in spring. Why does the calendar put them in July as well?
    Because the Valley can grow tomatoes twice and the second planting is the better one. A tomato set out in February and March flowers into June, and by the time the fruit is sizing the nights are past 80 °F and the pollen goes sterile: the plant holds green fruit that will not colour, and the plants that do survive the summer often ripen their crop on the autumn flush instead. Set out again in July and the plant establishes through the worst of the heat and crops hard from October into November. The county calendar carries both windows, and the July one is the one that is usually forgotten.
    The calendar shows lettuce in August. Is that not far too hot for lettuce?
    The sowing window and the growing weather are two different things, and the calendar is describing the first. Lettuce seeded in a shaded nursery bed in August, or started indoors and set out in September, will be a transplant going into cool soil just as the nights lengthen. Lettuce sown directly into a hot, bright bed in August will do very little. The window is early because lettuce has to be a reasonable size before the cool season closes in, and because seed that sits through the last of the heat germinates as soon as the soil temperature drops.
    What is the soil temperature for?
    Seed germination, mostly. Most common vegetable seed wants soil between about 65 °F and 85 °F. Below that range, seed sits and rots rather than sprouting, which is why direct-sowing beans into cold February ground fails while the same beans go in happily a month later. Above the range, germination drops off and seedlings stretch for light. The two seasons both exist because the soil temperature crosses that band twice a year, once on the way down and once on the way up.
    Why do some crops have a sowing window, a transplanting window and a sets window?
    Because there is more than one way to start them and the calendar gives all of them. “Sow” is seed into the ground where it will grow. “Transplant” is a seedling set out, which you either raised yourself or bought. It comes weeks after a sowing would have, and it needs a window of its own. “Sets” covers the crops grown from sets, cloves or slips rather than seed at all: garlic from cloves in October, bulb onions from sets through the winter, shallots in July. A crop with only one of the three columns filled is one the publication expects to be started that one way.
    When is the worst time to plant anything here?
    The few weeks either side of the summer solstice, in late June and early July. It is not that nothing will grow (some warm-season crops carry straight through it) but that it is the one stretch of the year when the soil is too hot for most seed to germinate and a seedling is up against 115 °F afternoons with a root system that cannot yet reach deep moisture. The calendar’s two seasons both thin out across those weeks, and the crops that fill them are the ones sown just before or just after.
    Does this calendar work for a container garden?
    The months do, with one adjustment. Soil in a pot swings far more than soil in the ground, so a container crosses the germination band sooner in spring and climbs past it sooner in summer, and it freezes harder and faster on a December night. Treat the same windows as the ground calendar but expect to shade a summer pot and to move it against a wall for winter, and expect to water far more often than a bed would need.