Frost Dates for Rio Rico, AZ 85648
Last spring frost April 8 · First fall frost November 9 · 215 frost-free days · USDA Zone 8b
ZIP 85648 has about 22,100 people.
Long season: 215 frost-free days. Spring frost risk spans March 13–May 3 (51 days). Fall frost risk spans October 24–November 24 (31 days).
Frost probability for 85648
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 3 | April 8 | March 13 |
| Fall (first frost) | October 24 | November 9 | November 24 |
Dates come from NOAA 1971–2000 freeze probabilities at TUMACACORI NM (7.3 km away); the 50% date is the median year.
Which crops fit a 215-day season in Rio Rico
In Rio Rico (215 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Mar 4 | Apr 22–Apr 29 | 173 | fits: 80 days to maturity, 173 available after Apr 22. | Jul 10 |
| Pepper | Feb 25 | Apr 22–Apr 29 | 173 | fits: 75 days to maturity, 173 available after Apr 22. | Jul 15 |
| Lettuce | Feb 11 | Mar 11–Mar 18 | 250 | two-plantings: Plant Mar 11 and again by Sep 18; both mature before Nov 16. | Sep 18 |
| Carrots | — | Mar 18–Mar 25 | 257 | fits: 70 days to maturity, 257 available after Mar 18. | Sep 7 |
| Cucumber | Mar 18 | Apr 22–Apr 29 | 187 | two-plantings: Plant Apr 22 and again by Aug 13; both mature before Oct 26. | Aug 13 |
| Beans | — | Apr 15–Apr 29 | 201 | two-plantings: Plant Apr 15 and again by Aug 20; both mature before Nov 2. | Aug 20 |
| Peas | — | Feb 11–Apr 22 | 278 | fits: 65 days to maturity, 278 available after Feb 11. | Aug 29 |
| Zucchini | Mar 25 | Apr 22–Apr 29 | 187 | two-plantings: Plant Apr 22 and again by Aug 18; both mature before Oct 26. | Aug 18 |
| Onion | Jan 14 | Mar 11–Mar 25 | 250 | fits: 100 days to maturity, 250 available after Mar 11. | — |
| Spinach | — | Feb 11–Apr 1 | 292 | two-plantings: Plant Feb 11 and again by Oct 7; both mature before Nov 30. | Oct 7 |
| Kale | Jan 28 | Mar 11–Mar 25 | 264 | two-plantings: Plant Mar 11 and again by Sep 22; both mature before Nov 30. | Sep 22 |
| Broccoli | Feb 11 | Mar 11–Mar 25 | 250 | fits: 80 days to maturity, 250 available after Mar 11. | Aug 14 |
| Cabbage | Feb 11 | Mar 11–Mar 25 | 264 | fits: 70 days to maturity, 264 available after Mar 11. | Sep 7 |
| Radish | — | Feb 11–May 6 | 278 | two-plantings: Plant Feb 11 and again by Oct 8; both mature before Nov 16. | Oct 8 |
| Beets | — | Feb 11–May 6 | 278 | two-plantings: Plant Feb 11 and again by Sep 8; both mature before Nov 16. | Sep 8 |
| Potatoes | — | Mar 25–Apr 1 | 236 | fits: 90 days to maturity, 236 available after Mar 25. | — |
| Garlic | — | Nov 9 | 320 | overwinter: Plant Nov 9 to Nov 30; harvest the following summer. | Nov 30 |
| Strawberry | — | Mar 4–Apr 29 | 271 | perennial: A perennial: plant Mar 4; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 11 | Apr 15–Apr 22 | 187 | fits: 75 days to maturity, 187 available after Apr 15. | Jul 22 |
| Pumpkin | Mar 25 | Apr 22–Apr 22 | 180 | fits: 100 days to maturity, 180 available after Apr 22. | Jun 27 |
| Cauliflower | Feb 25 | Apr 1–Apr 15 | 229 | fits: 75 days to maturity, 229 available after Apr 1. | Aug 19 |
| Swiss Chard | Feb 11 | Mar 25–Mar 25 | 236 | two-plantings: Plant Mar 25 and again by Sep 8; both mature before Nov 16. | Sep 8 |
| Arugula | — | Feb 11–May 6 | 292 | two-plantings: Plant Feb 11 and again by Oct 7; both mature before Nov 30. | Oct 7 |
| Brussel Sprouts | Feb 11 | Mar 11–Mar 25 | 264 | fits: 100 days to maturity, 264 available after Mar 11. | Aug 8 |
| Butternut Squash | Mar 25 | Apr 22–Apr 29 | 180 | fits: 100 days to maturity, 180 available after Apr 22. | Jun 27 |
| Eggplant | Feb 18 | Apr 22–Apr 29 | 173 | fits: 70 days to maturity, 173 available after Apr 22. | Jul 20 |
| Okra | Mar 11 | Apr 15–Apr 22 | 194 | two-plantings: Plant Apr 15 and again by Aug 18; both mature before Oct 26. | Aug 18 |
| Basil | Mar 4 | Apr 29–Apr 29 | 180 | two-plantings: Plant Apr 29 and again by Aug 13; both mature before Oct 26. | Aug 13 |
| Cilantro | — | Mar 11–Apr 1 | 250 | two-plantings: Plant Mar 11 and again by Sep 13; both mature before Nov 16. | Sep 13 |
| Parsley | Jan 28 | Apr 15–Apr 22 | 215 | fits: 70 days to maturity, 215 available after Apr 15. | Aug 24 |
| Celery | Jan 28 | Apr 15–Apr 29 | 215 | fits: 120 days to maturity, 215 available after Apr 15. | Jul 5 |
| Scallions | Jan 28 | Mar 11–Mar 25 | 264 | two-plantings: Plant Mar 11 and again by Sep 17; both mature before Nov 30. | Sep 17 |
| Turnip | — | Mar 11–Mar 25 | 264 | two-plantings: Plant Mar 11 and again by Sep 27; both mature before Nov 30. | Sep 27 |
| Kohlrabi | — | Feb 25–Mar 11 | 278 | two-plantings: Plant Feb 25 and again by Sep 22; both mature before Nov 30. | Sep 22 |
| Bok Choy | Mar 11 | Apr 1–Apr 8 | 229 | two-plantings: Plant Apr 1 and again by Sep 18; both mature before Nov 16. | Sep 18 |
| Collards | Jan 28 | Mar 11–Mar 25 | 264 | two-plantings: Plant Mar 11 and again by Sep 17; both mature before Nov 30. | Sep 17 |
| Cantaloupe | Mar 25 | Apr 22–Apr 29 | 173 | fits: 85 days to maturity, 173 available after Apr 22. | Jul 5 |
| Chives | Jan 14 | Apr 15–Apr 22 | 229 | fits: 90 days to maturity, 229 available after Apr 15. | — |
| Dill | — | Feb 11–May 6 | 278 | two-plantings: Plant Feb 11 and again by Sep 8; both mature before Nov 16. | Sep 8 |
| Oregano | Jan 28 | Apr 15–Apr 22 | 229 | fits: 80 days to maturity, 229 available after Apr 15. | — |
| Rosemary | Jan 14 | Apr 15–Apr 22 | 215 | fits: 80 days to maturity, 215 available after Apr 15. | — |
| Sage | Feb 11 | Apr 15–Apr 22 | 229 | fits: 75 days to maturity, 229 available after Apr 15. | — |
| Thyme | Jan 28 | Apr 15–Apr 22 | 229 | fits: 90 days to maturity, 229 available after Apr 15. | — |
| Calendula | Feb 25 | Mar 25–Apr 8 | 236 | two-plantings: Plant Mar 25 and again by Sep 13; both mature before Nov 16. | Sep 13 |
| Cosmos | Mar 11 | Apr 8–Apr 22 | 201 | two-plantings: Plant Apr 8 and again by Aug 13; both mature before Oct 26. | Aug 13 |
| Lavender | Jan 14 | Apr 8–Apr 22 | 236 | fits: 90 days to maturity, 236 available after Apr 8. | — |
| Marigolds | Feb 25 | Apr 8–Apr 15 | 201 | two-plantings: Plant Apr 8 and again by Aug 23; both mature before Oct 26. | Aug 23 |
| Melons | Mar 25 | Apr 22–Apr 29 | 173 | fits: 85 days to maturity, 173 available after Apr 22. | Jul 5 |
| Mint | — | Apr 8–Apr 22 | 236 | fits: 90 days to maturity, 236 available after Apr 8. | — |
| Nasturtiums | Mar 11 | Apr 8–Apr 15 | 201 | two-plantings: Plant Apr 8 and again by Aug 18; both mature before Oct 26. | Aug 18 |
| Pole Beans | — | Apr 15–Apr 29 | 194 | fits: 65 days to maturity, 194 available after Apr 15. | Aug 8 |
| Spaghetti Squash | Mar 25 | Apr 22–Apr 29 | 180 | fits: 90 days to maturity, 180 available after Apr 22. | Jul 7 |
| Sunflowers | — | Apr 8–Apr 22 | 201 | fits: 70 days to maturity, 201 available after Apr 8. | Aug 3 |
| Tomatillos | Feb 11 | Apr 15–Apr 22 | 180 | fits: 75 days to maturity, 180 available after Apr 15. | Jul 15 |
| Watermelon | Mar 25 | Apr 15–Apr 22 | 180 | fits: 80 days to maturity, 180 available after Apr 15. | Jul 10 |
| Yellow Squash | Mar 25 | Apr 22–Apr 29 | 187 | two-plantings: Plant Apr 22 and again by Aug 18; both mature before Oct 26. | Aug 18 |
| Zinnias | Mar 11 | Apr 8–Apr 22 | 201 | two-plantings: Plant Apr 8 and again by Aug 13; both mature before Oct 26. | Aug 13 |
Month by month in Rio Rico
| Month | What to do |
|---|---|
| January | Start indoors: Chives (Jan 14), Lavender (Jan 14), Onion (Jan 14), Rosemary (Jan 14), Celery (Jan 28), Collards (Jan 28), +5 more. |
| February | Start indoors: Broccoli (Feb 11), Brussel Sprouts (Feb 11), Cabbage (Feb 11), Lettuce (Feb 11), Sage (Feb 11), Swiss Chard (Feb 11), +6 more. Direct sow from: Arugula (Feb 11), Beets (Feb 11), Dill (Feb 11), Peas (Feb 11), Radish (Feb 11), Spinach (Feb 11), +1 more. |
| March | Start indoors: Basil (Mar 4), Tomato (Mar 4), Bok Choy (Mar 11), Corn (Mar 11), Cosmos (Mar 11), Nasturtiums (Mar 11), +11 more. Direct sow from: Cilantro (Mar 11), Turnip (Mar 11), Carrots (Mar 18), Potatoes (Mar 25). Transplant from: Broccoli (Mar 11), Brussel Sprouts (Mar 11), Cabbage (Mar 11), Collards (Mar 11), Kale (Mar 11), Lettuce (Mar 11), +4 more. Plant: Strawberry (Mar 4). |
| April | Direct sow from: Sunflowers (Apr 8), Beans (Apr 15), Pole Beans (Apr 15). Transplant from: Bok Choy (Apr 1), Cauliflower (Apr 1), Cosmos (Apr 8), Lavender (Apr 8), Marigolds (Apr 8), Mint (Apr 8), +25 more. Last frost around April 8. |
| May | Frost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini. |
| June | Last sowing dates: Butternut Squash (Jun 27), Pumpkin (Jun 27). |
| July | Last sowing dates: Cantaloupe (Jul 5), Celery (Jul 5), Melons (Jul 5), Spaghetti Squash (Jul 7), Tomato (Jul 10), Watermelon (Jul 10), +4 more. |
| August | Last sowing dates: Sunflowers (Aug 3), Brussel Sprouts (Aug 8), Pole Beans (Aug 8), Basil (Aug 13), Cosmos (Aug 13), Cucumber (Aug 13), +11 more. |
| September | Last sowing dates: Cabbage (Sep 7), Carrots (Sep 7), Beets (Sep 8), Dill (Sep 8), Swiss Chard (Sep 8), Calendula (Sep 13), +8 more. |
| October | Last sowing dates: Arugula (Oct 7), Spinach (Oct 7), Radish (Oct 8). |
| November | Direct sow from: Garlic (Nov 9). First frost around November 9. Last sowing dates: Garlic (Nov 30). |
| December | Harvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year. |
Frequently Asked Questions
What is the last frost date for Rio Rico, AZ (ZIP 85648)?
The median last spring frost date for Rio Rico, AZ (ZIP code 85648) is around April 8. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before March 13; one in ten it runs past May 3.
What is the first fall frost date in Rio Rico, AZ?
The median first fall frost date for Rio Rico, AZ is around November 9. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around October 24 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Rio Rico, AZ?
The frost-free growing season in Rio Rico is about 215 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Rio Rico (215 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Rio Rico, AZ?
Rio Rico, AZ is in USDA hardiness zone 8b (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Rio Rico, AZ?
Start tomatoes indoors Mar 4 and plant out Apr 22 in Rio Rico. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Rio Rico?
Two: plant Mar 11 and again by Sep 18; both mature before Nov 16.
When do I plant garlic in Rio Rico?
Nov 9 to Nov 30; it overwinters and is ready the following summer.
Can I get two tomato crops in Rio Rico?
Yes: plant out Apr 22 for a summer crop, and set out a second round of transplants by Jul 10 for a fall crop.
Which nearby ZIP has a longer season?
Green Valley (ZIP 85614) has 250 frost-free days, 35 more than Rio Rico (ZIP 85648). See Green Valley ZIP 85614 frost dates
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