What to plant in April in the Southwest

Worked out for 8 cities from their own weather and frost dates, by zone.

What to sow and plant in April in the Southwest, by zone: frost-free, highs above 82 °F (Phoenix, Tucson and 1 more): zucchini, green beans, basil, bok choy and borage; frost-free, highs of 72–82 °F (Las Vegas and Las Cruces): zucchini, green beans, basil, bok choy, borage and 1 more; frost possible, highs of 72–82 °F (Albuquerque): tomato, bell pepper, zucchini, cucumber, eggplant and 19 more; frost possible, highs of 61–72 °F (Santa Fe (United States) and Flagstaff): peas, lettuce, radish, Swiss chard, beet and 30 more.

In the Southwest, April is spring.

Frost-free, highs above 82 °F: Phoenix, Tucson and Yuma

In April, on average, these cities have highs of 85 to 90 °F and lows of 55 to 61 °F, 0.0 to 0.2 in of rain on 0 to 1 days; the day lasts 12 h 57 min to 13 h 00 min (on the 15th). A dry month: whatever is sown needs watering.

No frost in April in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.

How	What	Where
sow direct	Zucchini, green beans, basil, bok choy, borage	Phoenix and Tucson

Compared with March: no longer sown — cucumber, sweet corn, arugula, chayote, corn, Florence fennel, kiwano and Napa cabbage.

Not starting in April: tomato (January, started indoors), bell pepper (January, started indoors), lettuce (November, started indoors), peas (November, sown direct) and spinach (November, started indoors) — dates for Phoenix.

Ready to harvest in April in Phoenix, if sown in the right month: broad bean (January), peas (February), cabbage (December), beet (February), parsley (February), cilantro (February), arugula (March) and chamomile (February).

Frost-free, highs of 72–82 °F: Las Vegas and Las Cruces

In April, on average, these cities have highs of 80 to 81 °F and lows of 52 to 56 °F, 0.2 in of rain on 1 to 2 days; the day lasts 12 h 57 min to 13 h 06 min (on the 15th). A dry month: whatever is sown needs watering.

No frost in April in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.

How	What	Where
sow direct	Zucchini, green beans, basil, bok choy, borage	all
sow direct	Arugula	Las Vegas

Compared with March: new — green beans; no longer sown — peas, radish, beet, cucumber, sweet corn, parsley, cilantro, chamomile and 6 more.

Not starting in April: tomato (January, started indoors), bell pepper (January, started indoors), lettuce (November, sown direct), peas (November, sown direct) and spinach (November, sown direct) — dates for Las Vegas.

Ready to harvest in April in Las Vegas, if sown in the right month: broad bean (January), peas (February), lettuce (February), radish (March), cabbage (December), broccoli (January), Swiss chard (February) and beet (February).

Frost possible, highs of 72–82 °F: Albuquerque

In April, on average, Albuquerque has highs of 74 °F and lows of 44 °F, 0.7 in of rain on 4 days; the day lasts 13 h 03 min (on the 15th). A dry month: whatever is sown needs watering.

April falls in the frost season: frost-tender crops wait. Average last frost: Albuquerque (April 5).

How	What	Where
start indoors, plant out in June	Tomato, bell pepper, eggplant, chili pepper, Florence fennel, moringa	Albuquerque
start indoors, plant out in May	Zucchini, cucumber, melon, watermelon, pumpkin, sweet corn, basil, achocha, bok choy, kiwano, luffa, Napa cabbage, okra, peanut	Albuquerque
sow direct	Arugula	Albuquerque
start indoors, plant out in July	Celeriac, celery, chayote	Albuquerque

Compared with March: new — zucchini, cucumber, melon, watermelon, pumpkin, sweet corn, basil, achocha and 6 more; no longer sown — peas, lettuce, radish, Swiss chard, beet, parsley, cilantro, chamomile and 3 more.

Not starting in April: green beans (May, sown direct), lettuce (October, sown direct), peas (October, sown direct) and spinach (October, started indoors) — dates for Albuquerque.

Ready to harvest in April in Albuquerque, if sown in the right month: peas (February), spinach (February), lettuce (February), radish (March), Swiss chard (February), arugula (March), chamomile (February) and daikon (February).

Frost dates in Albuquerque

Frost possible, highs of 61–72 °F: Santa Fe (United States) and Flagstaff

In April, on average, these cities have highs of 63 to 64 °F and lows of 37 to 39 °F, 0.5 to 0.8 in of rain on 4 days; the day lasts 13 h 03 min to 13 h 05 min (on the 15th). A dry month: whatever is sown needs watering.

April falls in the frost season: frost-tender crops wait. Average last frost: Santa Fe (United States) (April 20).

How	What	Where
sow direct	Peas, lettuce, radish, Swiss chard, beet, parsley, cilantro, arugula, chamomile, dill, kohlrabi, mustard greens	all
start indoors, plant out in June	Tomato, bell pepper, eggplant, chili pepper, Florence fennel, moringa	all
start indoors, plant out in May	Zucchini, cucumber, melon, watermelon, pumpkin, sweet corn, basil, achocha, bok choy, kiwano, luffa, Napa cabbage, okra, peanut	Santa Fe (United States)
start indoors, plant out in July	Celeriac, celery, chayote	all

Compared with March: new — zucchini, cucumber, melon, watermelon, pumpkin, sweet corn, parsley, cilantro and 10 more; no longer sown — broad bean, onion, spinach, cabbage, daikon, kale, parsnip, shallot and 1 more.

Not starting in April: green beans (June, sown direct) and spinach (September, started indoors) — dates for Flagstaff.

Ready to harvest in April in Flagstaff, if sown in the right month: radish (March).

How we work it out

For each city we use its average weather in April and the months after (highs, lows and rain for 2016–2025, ERA5 reanalysis via Open-Meteo) and its average frost dates. A crop starts in April if the month's mean temperature reaches the minimum soil temperature for germination on its card (we use the mean air temperature as a stand-in for the soil's) and if, over its first months (up to three), the average highs stay within its group's range, with no frost for crops that cannot take it. Crops started indoors count from the month they are planted out.

Temperature groups from Colorado State University Extension: cool-season crops prefer 60–80 °F and lose quality in heat; hardy ones grow in days as cool as 40 °F, semi-hardy ones from 40–50 °F (we use 50 °F); warm-season crops need days above 55 °F, and the most tender (tomato, pepper, eggplant, melon, watermelon, squash) above 60 °F, up to 95 °F. Crops the guide does not name go into the stricter group by their frost hardiness. Fava (broad) beans, which the guide does not name, count as hardy: hardy varieties are sown in fall and overwinter (RHS). Garlic and bulbs: a month before the first frost, and later only while the ground is not frozen (as on each city's page).

This is a general rule from averages: your garden can be a week or two earlier or later, and a greenhouse or a cold frame brings the season forward. Greenly works out the dates for your location.