Frost Dates for Salt Lake City, UT 84109
Last spring frost May 21 · First fall frost September 29 · 131 frost-free days · USDA Zone 6b
ZIP 84109 has about 25,500 people, one of 24 ZIP codes in Salt Lake City.
Moderate season: 131 frost-free days. Spring frost risk spans May 2–June 10 (39 days). Fall frost risk spans September 14–October 13 (29 days).
Frost probability for 84109
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 10 | May 21 | May 2 |
| Fall (first frost) | September 14 | September 29 | October 13 |
Dates come from NOAA 1971–2000 freeze probabilities at MTN DELL DAM (5.4 km away); the 50% date is the median year.
Which crops fit a 131-day season in Salt Lake City
In Salt Lake City (131 frost-free days, a moderate season), 37 of 56 planner crops fit outright, 16 get two plantings, 2 need an indoor start, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Apr 16 | Jun 4–Jun 11 | 89 | fits: 80 days to maturity, 89 available after Jun 4. | — |
| Pepper | Apr 9 | Jun 4–Jun 11 | 89 | fits: 75 days to maturity, 89 available after Jun 4. | — |
| Lettuce | Mar 26 | Apr 23–Apr 30 | 166 | two-plantings: Plant Apr 23 and again by Aug 8; both mature before Oct 6. | Aug 8 |
| Carrots | — | Apr 30–May 7 | 173 | fits: 70 days to maturity, 173 available after Apr 30. | Jul 28 |
| Cucumber | Apr 30 | Jun 4–Jun 11 | 103 | fits: 60 days to maturity, 103 available after Jun 4. | Jul 3 |
| Beans | — | May 28–Jun 11 | 117 | fits: 60 days to maturity, 117 available after May 28. | Jul 10 |
| Peas | — | Mar 26–Jun 4 | 194 | fits: 65 days to maturity, 194 available after Mar 26. | Jul 19 |
| Zucchini | May 7 | Jun 4–Jun 11 | 103 | fits: 55 days to maturity, 103 available after Jun 4. | Jul 8 |
| Onion | Feb 26 | Apr 23–May 7 | 166 | fits: 100 days to maturity, 166 available after Apr 23. | — |
| Spinach | — | Mar 26–May 14 | 208 | two-plantings: Plant Mar 26 and again by Aug 27; both mature before Oct 20. | Aug 27 |
| Kale | Mar 12 | Apr 23–May 7 | 180 | two-plantings: Plant Apr 23 and again by Aug 12; both mature before Oct 20. | Aug 12 |
| Broccoli | Mar 26 | Apr 23–May 7 | 166 | fits: 80 days to maturity, 166 available after Apr 23. | Jul 4 |
| Cabbage | Mar 26 | Apr 23–May 7 | 180 | fits: 70 days to maturity, 180 available after Apr 23. | Jul 28 |
| Radish | — | Mar 26–Jun 18 | 194 | two-plantings: Plant Mar 26 and again by Aug 28; both mature before Oct 6. | Aug 28 |
| Beets | — | Mar 26–Jun 18 | 194 | two-plantings: Plant Mar 26 and again by Jul 29; both mature before Oct 6. | Jul 29 |
| Potatoes | — | May 7–May 14 | 152 | fits: 90 days to maturity, 152 available after May 7. | — |
| Garlic | — | Sep 29 | 236 | overwinter: Plant Sep 29 to Oct 20; harvest the following summer. | Oct 20 |
| Strawberry | — | Apr 16–Jun 11 | 187 | perennial: A perennial: plant Apr 16; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 23 | May 28–Jun 4 | 103 | fits: 75 days to maturity, 103 available after May 28. | Jun 11 |
| Pumpkin | May 7 | Jun 4–Jun 4 | 96 | head-start: Even planted out Jun 4, the outdoor season is about 4 days short; choose an early variety or grow under cover. | — |
| Cauliflower | Apr 9 | May 14–May 28 | 145 | fits: 75 days to maturity, 145 available after May 14. | Jul 9 |
| Swiss Chard | Mar 26 | May 7–May 7 | 152 | two-plantings: Plant May 7 and again by Jul 29; both mature before Oct 6. | Jul 29 |
| Arugula | — | Mar 26–Jun 18 | 208 | two-plantings: Plant Mar 26 and again by Aug 27; both mature before Oct 20. | Aug 27 |
| Brussel Sprouts | Mar 26 | Apr 23–May 7 | 180 | fits: 100 days to maturity, 180 available after Apr 23. | Jun 28 |
| Butternut Squash | May 7 | Jun 4–Jun 11 | 96 | head-start: Even planted out Jun 4, the outdoor season is about 4 days short; choose an early variety or grow under cover. | — |
| Eggplant | Apr 2 | Jun 4–Jun 11 | 89 | fits: 70 days to maturity, 89 available after Jun 4. | Jun 9 |
| Okra | Apr 23 | May 28–Jun 4 | 110 | fits: 55 days to maturity, 110 available after May 28. | Jul 8 |
| Basil | Apr 16 | Jun 11–Jun 11 | 96 | fits: 60 days to maturity, 96 available after Jun 11. | Jul 3 |
| Cilantro | — | Apr 23–May 14 | 166 | two-plantings: Plant Apr 23 and again by Aug 3; both mature before Oct 6. | Aug 3 |
| Parsley | Mar 12 | May 28–Jun 4 | 131 | fits: 70 days to maturity, 131 available after May 28. | Jul 14 |
| Celery | Mar 12 | May 28–Jun 11 | 131 | fits: 120 days to maturity, 131 available after May 28. | — |
| Scallions | Mar 12 | Apr 23–May 7 | 180 | two-plantings: Plant Apr 23 and again by Aug 7; both mature before Oct 20. | Aug 7 |
| Turnip | — | Apr 23–May 7 | 180 | two-plantings: Plant Apr 23 and again by Aug 17; both mature before Oct 20. | Aug 17 |
| Kohlrabi | — | Apr 9–Apr 23 | 194 | two-plantings: Plant Apr 9 and again by Aug 12; both mature before Oct 20. | Aug 12 |
| Bok Choy | Apr 23 | May 14–May 21 | 145 | two-plantings: Plant May 14 and again by Aug 8; both mature before Oct 6. | Aug 8 |
| Collards | Mar 12 | Apr 23–May 7 | 180 | two-plantings: Plant Apr 23 and again by Aug 7; both mature before Oct 20. | Aug 7 |
| Cantaloupe | May 7 | Jun 4–Jun 11 | 89 | fits: 85 days to maturity, 89 available after Jun 4. | — |
| Chives | Feb 26 | May 28–Jun 4 | 145 | fits: 90 days to maturity, 145 available after May 28. | — |
| Dill | — | Mar 26–Jun 18 | 194 | two-plantings: Plant Mar 26 and again by Jul 29; both mature before Oct 6. | Jul 29 |
| Oregano | Mar 12 | May 28–Jun 4 | 145 | fits: 80 days to maturity, 145 available after May 28. | — |
| Rosemary | Feb 26 | May 28–Jun 4 | 131 | fits: 80 days to maturity, 131 available after May 28. | — |
| Sage | Mar 26 | May 28–Jun 4 | 145 | fits: 75 days to maturity, 145 available after May 28. | — |
| Thyme | Mar 12 | May 28–Jun 4 | 145 | fits: 90 days to maturity, 145 available after May 28. | — |
| Calendula | Apr 9 | May 7–May 21 | 152 | two-plantings: Plant May 7 and again by Aug 3; both mature before Oct 6. | Aug 3 |
| Cosmos | Apr 23 | May 21–Jun 4 | 117 | fits: 60 days to maturity, 117 available after May 21. | Jul 3 |
| Lavender | Feb 26 | May 21–Jun 4 | 152 | fits: 90 days to maturity, 152 available after May 21. | — |
| Marigolds | Apr 9 | May 21–May 28 | 117 | two-plantings: Plant May 21 and again by Jul 13; both mature before Sep 15. | Jul 13 |
| Melons | May 7 | Jun 4–Jun 11 | 89 | fits: 85 days to maturity, 89 available after Jun 4. | — |
| Mint | — | May 21–Jun 4 | 152 | fits: 90 days to maturity, 152 available after May 21. | — |
| Nasturtiums | Apr 23 | May 21–May 28 | 117 | fits: 55 days to maturity, 117 available after May 21. | Jul 8 |
| Pole Beans | — | May 28–Jun 11 | 110 | fits: 65 days to maturity, 110 available after May 28. | Jun 28 |
| Spaghetti Squash | May 7 | Jun 4–Jun 11 | 96 | fits: 90 days to maturity, 96 available after Jun 4. | — |
| Sunflowers | — | May 21–Jun 4 | 117 | fits: 70 days to maturity, 117 available after May 21. | Jun 23 |
| Tomatillos | Mar 26 | May 28–Jun 4 | 96 | fits: 75 days to maturity, 96 available after May 28. | Jun 4 |
| Watermelon | May 7 | May 28–Jun 4 | 96 | fits: 80 days to maturity, 96 available after May 28. | May 30 |
| Yellow Squash | May 7 | Jun 4–Jun 11 | 103 | fits: 55 days to maturity, 103 available after Jun 4. | Jul 8 |
| Zinnias | Apr 23 | May 21–Jun 4 | 117 | fits: 60 days to maturity, 117 available after May 21. | Jul 3 |
Month by month in Salt Lake City
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 26), Lavender (Feb 26), Onion (Feb 26), Rosemary (Feb 26). |
| March | Start indoors: Celery (Mar 12), Collards (Mar 12), Kale (Mar 12), Oregano (Mar 12), Parsley (Mar 12), Scallions (Mar 12), +8 more. Direct sow from: Arugula (Mar 26), Beets (Mar 26), Dill (Mar 26), Peas (Mar 26), Radish (Mar 26), Spinach (Mar 26). |
| April | Start indoors: Eggplant (Apr 2), Calendula (Apr 9), Cauliflower (Apr 9), Marigolds (Apr 9), Pepper (Apr 9), Basil (Apr 16), +8 more. Direct sow from: Kohlrabi (Apr 9), Cilantro (Apr 23), Turnip (Apr 23), Carrots (Apr 30). Transplant from: Broccoli (Apr 23), Brussel Sprouts (Apr 23), Cabbage (Apr 23), Collards (Apr 23), Kale (Apr 23), Lettuce (Apr 23), +2 more. Plant: Strawberry (Apr 16). |
| May | Start indoors: Butternut Squash (May 7), Cantaloupe (May 7), Melons (May 7), Pumpkin (May 7), Spaghetti Squash (May 7), Watermelon (May 7), +2 more. Direct sow from: Potatoes (May 7), Sunflowers (May 21), Beans (May 28), Pole Beans (May 28). Transplant from: Calendula (May 7), Swiss Chard (May 7), Bok Choy (May 14), Cauliflower (May 14), Cosmos (May 21), Lavender (May 21), +15 more. Last frost around May 21. Last sowing dates: Watermelon (May 30). |
| June | Transplant from: Butternut Squash (Jun 4), Cantaloupe (Jun 4), Cucumber (Jun 4), Eggplant (Jun 4), Melons (Jun 4), Pepper (Jun 4), +6 more. Last sowing dates: Tomatillos (Jun 4), Eggplant (Jun 9), Corn (Jun 11), Sunflowers (Jun 23), Brussel Sprouts (Jun 28), Pole Beans (Jun 28). |
| July | Last sowing dates: Basil (Jul 3), Cosmos (Jul 3), Cucumber (Jul 3), Zinnias (Jul 3), Broccoli (Jul 4), Nasturtiums (Jul 8), +13 more. |
| August | Last sowing dates: Calendula (Aug 3), Cilantro (Aug 3), Collards (Aug 7), Scallions (Aug 7), Bok Choy (Aug 8), Lettuce (Aug 8), +6 more. |
| September | Direct sow from: Garlic (Sep 29). First frost around September 29. |
| October | Last sowing dates: Garlic (Oct 20). |
| November | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
| December | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
Frequently Asked Questions
What is the last frost date for Salt Lake City, UT (ZIP 84109)?
The median last spring frost date for Salt Lake City, UT (ZIP code 84109) is around May 21. 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 May 2; one in ten it runs past June 10.
What is the first fall frost date in Salt Lake City, UT?
The median first fall frost date for Salt Lake City, UT is around September 29. 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 September 14 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Salt Lake City, UT?
The frost-free growing season in Salt Lake City is about 131 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 Salt Lake City (131 frost-free days, a moderate season), 37 of 56 planner crops fit outright, 16 get two plantings, 2 need an indoor start, 1 crop is perennial.
What USDA hardiness zone is Salt Lake City, UT?
Salt Lake City, UT is in USDA hardiness zone 6b (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 Salt Lake City, UT?
Start tomatoes indoors Apr 16 and plant out Jun 4 in Salt Lake City. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Salt Lake City?
Two: plant Apr 23 and again by Aug 8; both mature before Oct 6.
When do I plant garlic in Salt Lake City?
Sep 29 to Oct 20; it overwinters and is ready the following summer.
Can I grow Butternut Squash in Salt Lake City?
Yes, with help. Even planted out Jun 4, the outdoor season is about 4 days short; choose an early variety or grow under cover.
Which nearby ZIP has a longer season?
Salt Lake City (ZIP 84105) has 174 frost-free days, 43 more than Salt Lake City (ZIP 84109). See Salt Lake City ZIP 84105 frost dates
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