Frost Dates for Vernal, UT 84078
Last spring frost May 20 · First fall frost September 23 · 126 frost-free days · USDA Zone 5b
ZIP 84078 has about 31,000 people.
Moderate season: 126 frost-free days. Spring frost risk spans April 30–June 8 (39 days). Fall frost risk spans September 12–October 5 (23 days).
Frost probability for 84078
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 8 | May 20 | April 30 |
| Fall (first frost) | September 12 | September 23 | October 5 |
Dates come from NOAA 1971–2000 freeze probabilities at JENSEN (17.7 km away); the 50% date is the median year.
Which crops fit a 126-day season in Vernal
In Vernal (126 frost-free days, a moderate season), 36 of 56 planner crops fit outright, 15 get two plantings, 4 need an indoor start, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Apr 15 | Jun 3–Jun 10 | 84 | fits: 80 days to maturity, 84 available after Jun 3. | — |
| Pepper | Apr 8 | Jun 3–Jun 10 | 84 | fits: 75 days to maturity, 84 available after Jun 3. | — |
| Lettuce | Mar 25 | Apr 22–Apr 29 | 161 | two-plantings: Plant Apr 22 and again by Aug 2; both mature before Sep 30. | Aug 2 |
| Carrots | — | Apr 29–May 6 | 168 | fits: 70 days to maturity, 168 available after Apr 29. | Jul 22 |
| Cucumber | Apr 29 | Jun 3–Jun 10 | 98 | fits: 60 days to maturity, 98 available after Jun 3. | Jun 27 |
| Beans | — | May 27–Jun 10 | 112 | fits: 60 days to maturity, 112 available after May 27. | Jul 4 |
| Peas | — | Mar 25–Jun 3 | 189 | fits: 65 days to maturity, 189 available after Mar 25. | Jul 13 |
| Zucchini | May 6 | Jun 3–Jun 10 | 98 | fits: 55 days to maturity, 98 available after Jun 3. | Jul 2 |
| Onion | Feb 25 | Apr 22–May 6 | 161 | fits: 100 days to maturity, 161 available after Apr 22. | — |
| Spinach | — | Mar 25–May 13 | 203 | two-plantings: Plant Mar 25 and again by Aug 21; both mature before Oct 14. | Aug 21 |
| Kale | Mar 11 | Apr 22–May 6 | 175 | two-plantings: Plant Apr 22 and again by Aug 6; both mature before Oct 14. | Aug 6 |
| Broccoli | Mar 25 | Apr 22–May 6 | 161 | fits: 80 days to maturity, 161 available after Apr 22. | Jun 28 |
| Cabbage | Mar 25 | Apr 22–May 6 | 175 | fits: 70 days to maturity, 175 available after Apr 22. | Jul 22 |
| Radish | — | Mar 25–Jun 17 | 189 | two-plantings: Plant Mar 25 and again by Aug 22; both mature before Sep 30. | Aug 22 |
| Beets | — | Mar 25–Jun 17 | 189 | two-plantings: Plant Mar 25 and again by Jul 23; both mature before Sep 30. | Jul 23 |
| Potatoes | — | May 6–May 13 | 147 | fits: 90 days to maturity, 147 available after May 6. | — |
| Garlic | — | Sep 23 | 231 | overwinter: Plant Sep 23 to Oct 14; harvest the following summer. | Oct 14 |
| Strawberry | — | Apr 15–Jun 10 | 182 | perennial: A perennial: plant Apr 15; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 22 | May 27–Jun 3 | 98 | fits: 75 days to maturity, 98 available after May 27. | Jun 5 |
| Pumpkin | May 6 | Jun 3–Jun 3 | 91 | head-start: Even planted out Jun 3, the outdoor season is about 9 days short; choose an early variety or grow under cover. | — |
| Cauliflower | Apr 8 | May 13–May 27 | 140 | fits: 75 days to maturity, 140 available after May 13. | Jul 3 |
| Swiss Chard | Mar 25 | May 6–May 6 | 147 | two-plantings: Plant May 6 and again by Jul 23; both mature before Sep 30. | Jul 23 |
| Arugula | — | Mar 25–Jun 17 | 203 | two-plantings: Plant Mar 25 and again by Aug 21; both mature before Oct 14. | Aug 21 |
| Brussel Sprouts | Mar 25 | Apr 22–May 6 | 175 | fits: 100 days to maturity, 175 available after Apr 22. | Jun 22 |
| Butternut Squash | May 6 | Jun 3–Jun 10 | 91 | head-start: Even planted out Jun 3, the outdoor season is about 9 days short; choose an early variety or grow under cover. | — |
| Eggplant | Apr 1 | Jun 3–Jun 10 | 84 | fits: 70 days to maturity, 84 available after Jun 3. | — |
| Okra | Apr 22 | May 27–Jun 3 | 105 | fits: 55 days to maturity, 105 available after May 27. | Jul 2 |
| Basil | Apr 15 | Jun 10–Jun 10 | 91 | fits: 60 days to maturity, 91 available after Jun 10. | Jun 27 |
| Cilantro | — | Apr 22–May 13 | 161 | two-plantings: Plant Apr 22 and again by Jul 28; both mature before Sep 30. | Jul 28 |
| Parsley | Mar 11 | May 27–Jun 3 | 126 | fits: 70 days to maturity, 126 available after May 27. | Jul 8 |
| Celery | Mar 11 | May 27–Jun 10 | 126 | fits: 120 days to maturity, 126 available after May 27. | — |
| Scallions | Mar 11 | Apr 22–May 6 | 175 | two-plantings: Plant Apr 22 and again by Aug 1; both mature before Oct 14. | Aug 1 |
| Turnip | — | Apr 22–May 6 | 175 | two-plantings: Plant Apr 22 and again by Aug 11; both mature before Oct 14. | Aug 11 |
| Kohlrabi | — | Apr 8–Apr 22 | 189 | two-plantings: Plant Apr 8 and again by Aug 6; both mature before Oct 14. | Aug 6 |
| Bok Choy | Apr 22 | May 13–May 20 | 140 | two-plantings: Plant May 13 and again by Aug 2; both mature before Sep 30. | Aug 2 |
| Collards | Mar 11 | Apr 22–May 6 | 175 | two-plantings: Plant Apr 22 and again by Aug 1; both mature before Oct 14. | Aug 1 |
| Cantaloupe | May 6 | Jun 3–Jun 10 | 84 | head-start: Even planted out Jun 3, the outdoor season is about 1 days short; choose an early variety or grow under cover. | — |
| Chives | Feb 25 | May 27–Jun 3 | 140 | fits: 90 days to maturity, 140 available after May 27. | — |
| Dill | — | Mar 25–Jun 17 | 189 | two-plantings: Plant Mar 25 and again by Jul 23; both mature before Sep 30. | Jul 23 |
| Oregano | Mar 11 | May 27–Jun 3 | 140 | fits: 80 days to maturity, 140 available after May 27. | — |
| Rosemary | Feb 25 | May 27–Jun 3 | 126 | fits: 80 days to maturity, 126 available after May 27. | — |
| Sage | Mar 25 | May 27–Jun 3 | 140 | fits: 75 days to maturity, 140 available after May 27. | — |
| Thyme | Mar 11 | May 27–Jun 3 | 140 | fits: 90 days to maturity, 140 available after May 27. | — |
| Calendula | Apr 8 | May 6–May 20 | 147 | two-plantings: Plant May 6 and again by Jul 28; both mature before Sep 30. | Jul 28 |
| Cosmos | Apr 22 | May 20–Jun 3 | 112 | fits: 60 days to maturity, 112 available after May 20. | Jun 27 |
| Lavender | Feb 25 | May 20–Jun 3 | 147 | fits: 90 days to maturity, 147 available after May 20. | — |
| Marigolds | Apr 8 | May 20–May 27 | 112 | fits: 50 days to maturity, 112 available after May 20. | Jul 7 |
| Melons | May 6 | Jun 3–Jun 10 | 84 | head-start: Even planted out Jun 3, the outdoor season is about 1 days short; choose an early variety or grow under cover. | — |
| Mint | — | May 20–Jun 3 | 147 | fits: 90 days to maturity, 147 available after May 20. | — |
| Nasturtiums | Apr 22 | May 20–May 27 | 112 | fits: 55 days to maturity, 112 available after May 20. | Jul 2 |
| Pole Beans | — | May 27–Jun 10 | 105 | fits: 65 days to maturity, 105 available after May 27. | Jun 22 |
| Spaghetti Squash | May 6 | Jun 3–Jun 10 | 91 | fits: 90 days to maturity, 91 available after Jun 3. | — |
| Sunflowers | — | May 20–Jun 3 | 112 | fits: 70 days to maturity, 112 available after May 20. | Jun 17 |
| Tomatillos | Mar 25 | May 27–Jun 3 | 91 | fits: 75 days to maturity, 91 available after May 27. | May 29 |
| Watermelon | May 6 | May 27–Jun 3 | 91 | fits: 80 days to maturity, 91 available after May 27. | — |
| Yellow Squash | May 6 | Jun 3–Jun 10 | 98 | fits: 55 days to maturity, 98 available after Jun 3. | Jul 2 |
| Zinnias | Apr 22 | May 20–Jun 3 | 112 | fits: 60 days to maturity, 112 available after May 20. | Jun 27 |
Month by month in Vernal
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 25), Lavender (Feb 25), Onion (Feb 25), Rosemary (Feb 25). |
| March | Start indoors: Celery (Mar 11), Collards (Mar 11), Kale (Mar 11), Oregano (Mar 11), Parsley (Mar 11), Scallions (Mar 11), +8 more. Direct sow from: Arugula (Mar 25), Beets (Mar 25), Dill (Mar 25), Peas (Mar 25), Radish (Mar 25), Spinach (Mar 25). |
| April | Start indoors: Eggplant (Apr 1), Calendula (Apr 8), Cauliflower (Apr 8), Marigolds (Apr 8), Pepper (Apr 8), Basil (Apr 15), +8 more. Direct sow from: Kohlrabi (Apr 8), Cilantro (Apr 22), Turnip (Apr 22), Carrots (Apr 29). Transplant from: Broccoli (Apr 22), Brussel Sprouts (Apr 22), Cabbage (Apr 22), Collards (Apr 22), Kale (Apr 22), Lettuce (Apr 22), +2 more. Plant: Strawberry (Apr 15). |
| May | Start indoors: Butternut Squash (May 6), Cantaloupe (May 6), Melons (May 6), Pumpkin (May 6), Spaghetti Squash (May 6), Watermelon (May 6), +2 more. Direct sow from: Potatoes (May 6), Sunflowers (May 20), Beans (May 27), Pole Beans (May 27). Transplant from: Calendula (May 6), Swiss Chard (May 6), Bok Choy (May 13), Cauliflower (May 13), Cosmos (May 20), Lavender (May 20), +15 more. Last frost around May 20. Last sowing dates: Tomatillos (May 29). |
| June | Transplant from: Butternut Squash (Jun 3), Cantaloupe (Jun 3), Cucumber (Jun 3), Eggplant (Jun 3), Melons (Jun 3), Pepper (Jun 3), +6 more. Last sowing dates: Corn (Jun 5), Sunflowers (Jun 17), Brussel Sprouts (Jun 22), Pole Beans (Jun 22), Basil (Jun 27), Cosmos (Jun 27), +3 more. |
| July | Last sowing dates: Nasturtiums (Jul 2), Okra (Jul 2), Yellow Squash (Jul 2), Zucchini (Jul 2), Cauliflower (Jul 3), Beans (Jul 4), +10 more. |
| August | Last sowing dates: Collards (Aug 1), Scallions (Aug 1), Bok Choy (Aug 2), Lettuce (Aug 2), Kale (Aug 6), Kohlrabi (Aug 6), +4 more. |
| September | Direct sow from: Garlic (Sep 23). First frost around September 23. |
| October | Last sowing dates: Garlic (Oct 14). |
| 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 Vernal, UT (ZIP 84078)?
The median last spring frost date for Vernal, UT (ZIP code 84078) is around May 20. 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 April 30; one in ten it runs past June 8.
What is the first fall frost date in Vernal, UT?
The median first fall frost date for Vernal, UT is around September 23. 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 12 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Vernal, UT?
The frost-free growing season in Vernal is about 126 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 Vernal (126 frost-free days, a moderate season), 36 of 56 planner crops fit outright, 15 get two plantings, 4 need an indoor start, 1 crop is perennial.
What USDA hardiness zone is Vernal, UT?
Vernal, UT is in USDA hardiness zone 5b (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 Vernal, UT?
Start tomatoes indoors Apr 15 and plant out Jun 3 in Vernal. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Vernal?
Two: plant Apr 22 and again by Aug 2; both mature before Sep 30.
When do I plant garlic in Vernal?
Sep 23 to Oct 14; it overwinters and is ready the following summer.
Can I grow Butternut Squash in Vernal?
Yes, with help. Even planted out Jun 3, the outdoor season is about 9 days short; choose an early variety or grow under cover.
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