Frost Dates for Waterloo, IA 50702
Waterloo has 3 ZIP codes. The Waterloo, IA frost page lists all of them with their dates.
Last spring frost April 28 · First fall frost October 2 · 157 frost-free days · USDA Zone 5a
ZIP 50702 has about 20,900 people, one of 3 ZIP codes in Waterloo.
Moderate season: 157 frost-free days. Spring frost risk spans April 14–May 12 (28 days). Fall frost risk spans September 20–October 15 (25 days).
Frost probability for 50702
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 12 | April 28 | April 14 |
| Fall (first frost) | September 20 | October 2 | October 15 |
Dates come from NOAA 1971–2000 freeze probabilities at TRIPOLI (39.7 km away); the 50% date is the median year.
Which crops fit a 157-day season in Waterloo
In Waterloo (157 frost-free days, a moderate season), 32 of 56 planner crops fit outright, 23 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Mar 24 | May 12–May 19 | 115 | fits: 80 days to maturity, 115 available after May 12. | Jun 2 |
| Pepper | Mar 17 | May 12–May 19 | 115 | fits: 75 days to maturity, 115 available after May 12. | Jun 7 |
| Lettuce | Mar 3 | Mar 31–Apr 7 | 192 | two-plantings: Plant Mar 31 and again by Aug 11; both mature before Oct 9. | Aug 11 |
| Carrots | — | Apr 7–Apr 14 | 199 | fits: 70 days to maturity, 199 available after Apr 7. | Jul 31 |
| Cucumber | Apr 7 | May 12–May 19 | 129 | fits: 60 days to maturity, 129 available after May 12. | Jul 6 |
| Beans | — | May 5–May 19 | 143 | two-plantings: Plant May 5 and again by Jul 13; both mature before Sep 25. | Jul 13 |
| Peas | — | Mar 3–May 12 | 220 | fits: 65 days to maturity, 220 available after Mar 3. | Jul 22 |
| Zucchini | Apr 14 | May 12–May 19 | 129 | two-plantings: Plant May 12 and again by Jul 11; both mature before Sep 18. | Jul 11 |
| Onion | Feb 3 | Mar 31–Apr 14 | 192 | fits: 100 days to maturity, 192 available after Mar 31. | — |
| Spinach | — | Mar 3–Apr 21 | 234 | two-plantings: Plant Mar 3 and again by Aug 30; both mature before Oct 23. | Aug 30 |
| Kale | Feb 17 | Mar 31–Apr 14 | 206 | two-plantings: Plant Mar 31 and again by Aug 15; both mature before Oct 23. | Aug 15 |
| Broccoli | Mar 3 | Mar 31–Apr 14 | 192 | fits: 80 days to maturity, 192 available after Mar 31. | Jul 7 |
| Cabbage | Mar 3 | Mar 31–Apr 14 | 206 | fits: 70 days to maturity, 206 available after Mar 31. | Jul 31 |
| Radish | — | Mar 3–May 26 | 220 | two-plantings: Plant Mar 3 and again by Aug 31; both mature before Oct 9. | Aug 31 |
| Beets | — | Mar 3–May 26 | 220 | two-plantings: Plant Mar 3 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Potatoes | — | Apr 14–Apr 21 | 178 | fits: 90 days to maturity, 178 available after Apr 14. | — |
| Garlic | — | Oct 2 | 262 | overwinter: Plant Oct 2 to Oct 23; harvest the following summer. | Oct 23 |
| Strawberry | — | Mar 24–May 19 | 213 | perennial: A perennial: plant Mar 24; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 31 | May 5–May 12 | 129 | fits: 75 days to maturity, 129 available after May 5. | Jun 14 |
| Pumpkin | Apr 14 | May 12–May 12 | 122 | fits: 100 days to maturity, 122 available after May 12. | May 20 |
| Cauliflower | Mar 17 | Apr 21–May 5 | 171 | fits: 75 days to maturity, 171 available after Apr 21. | Jul 12 |
| Swiss Chard | Mar 3 | Apr 14–Apr 14 | 178 | two-plantings: Plant Apr 14 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Arugula | — | Mar 3–May 26 | 234 | two-plantings: Plant Mar 3 and again by Aug 30; both mature before Oct 23. | Aug 30 |
| Brussel Sprouts | Mar 3 | Mar 31–Apr 14 | 206 | fits: 100 days to maturity, 206 available after Mar 31. | Jul 1 |
| Butternut Squash | Apr 14 | May 12–May 19 | 122 | fits: 100 days to maturity, 122 available after May 12. | May 20 |
| Eggplant | Mar 10 | May 12–May 19 | 115 | fits: 70 days to maturity, 115 available after May 12. | Jun 12 |
| Okra | Mar 31 | May 5–May 12 | 136 | two-plantings: Plant May 5 and again by Jul 11; both mature before Sep 18. | Jul 11 |
| Basil | Mar 24 | May 19–May 19 | 122 | fits: 60 days to maturity, 122 available after May 19. | Jul 6 |
| Cilantro | — | Mar 31–Apr 21 | 192 | two-plantings: Plant Mar 31 and again by Aug 6; both mature before Oct 9. | Aug 6 |
| Parsley | Feb 17 | May 5–May 12 | 157 | fits: 70 days to maturity, 157 available after May 5. | Jul 17 |
| Celery | Feb 17 | May 5–May 19 | 157 | fits: 120 days to maturity, 157 available after May 5. | May 28 |
| Scallions | Feb 17 | Mar 31–Apr 14 | 206 | two-plantings: Plant Mar 31 and again by Aug 10; both mature before Oct 23. | Aug 10 |
| Turnip | — | Mar 31–Apr 14 | 206 | two-plantings: Plant Mar 31 and again by Aug 20; both mature before Oct 23. | Aug 20 |
| Kohlrabi | — | Mar 17–Mar 31 | 220 | two-plantings: Plant Mar 17 and again by Aug 15; both mature before Oct 23. | Aug 15 |
| Bok Choy | Mar 31 | Apr 21–Apr 28 | 171 | two-plantings: Plant Apr 21 and again by Aug 11; both mature before Oct 9. | Aug 11 |
| Collards | Feb 17 | Mar 31–Apr 14 | 206 | two-plantings: Plant Mar 31 and again by Aug 10; both mature before Oct 23. | Aug 10 |
| Cantaloupe | Apr 14 | May 12–May 19 | 115 | fits: 85 days to maturity, 115 available after May 12. | May 28 |
| Chives | Feb 3 | May 5–May 12 | 171 | fits: 90 days to maturity, 171 available after May 5. | — |
| Dill | — | Mar 3–May 26 | 220 | two-plantings: Plant Mar 3 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Oregano | Feb 17 | May 5–May 12 | 171 | fits: 80 days to maturity, 171 available after May 5. | — |
| Rosemary | Feb 3 | May 5–May 12 | 157 | fits: 80 days to maturity, 157 available after May 5. | — |
| Sage | Mar 3 | May 5–May 12 | 171 | fits: 75 days to maturity, 171 available after May 5. | — |
| Thyme | Feb 17 | May 5–May 12 | 171 | fits: 90 days to maturity, 171 available after May 5. | — |
| Calendula | Mar 17 | Apr 14–Apr 28 | 178 | two-plantings: Plant Apr 14 and again by Aug 6; both mature before Oct 9. | Aug 6 |
| Cosmos | Mar 31 | Apr 28–May 12 | 143 | two-plantings: Plant Apr 28 and again by Jul 6; both mature before Sep 18. | Jul 6 |
| Lavender | Feb 3 | Apr 28–May 12 | 178 | fits: 90 days to maturity, 178 available after Apr 28. | — |
| Marigolds | Mar 17 | Apr 28–May 5 | 143 | two-plantings: Plant Apr 28 and again by Jul 16; both mature before Sep 18. | Jul 16 |
| Melons | Apr 14 | May 12–May 19 | 115 | fits: 85 days to maturity, 115 available after May 12. | May 28 |
| Mint | — | Apr 28–May 12 | 178 | fits: 90 days to maturity, 178 available after Apr 28. | — |
| Nasturtiums | Mar 31 | Apr 28–May 5 | 143 | two-plantings: Plant Apr 28 and again by Jul 11; both mature before Sep 18. | Jul 11 |
| Pole Beans | — | May 5–May 19 | 136 | fits: 65 days to maturity, 136 available after May 5. | Jul 1 |
| Spaghetti Squash | Apr 14 | May 12–May 19 | 122 | fits: 90 days to maturity, 122 available after May 12. | May 30 |
| Sunflowers | — | Apr 28–May 12 | 143 | fits: 70 days to maturity, 143 available after Apr 28. | Jun 26 |
| Tomatillos | Mar 3 | May 5–May 12 | 122 | fits: 75 days to maturity, 122 available after May 5. | Jun 7 |
| Watermelon | Apr 14 | May 5–May 12 | 122 | fits: 80 days to maturity, 122 available after May 5. | Jun 2 |
| Yellow Squash | Apr 14 | May 12–May 19 | 129 | two-plantings: Plant May 12 and again by Jul 11; both mature before Sep 18. | Jul 11 |
| Zinnias | Mar 31 | Apr 28–May 12 | 143 | two-plantings: Plant Apr 28 and again by Jul 6; both mature before Sep 18. | Jul 6 |
Month by month in Waterloo
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 3), Lavender (Feb 3), Onion (Feb 3), Rosemary (Feb 3), Celery (Feb 17), Collards (Feb 17), +5 more. |
| March | Start indoors: Broccoli (Mar 3), Brussel Sprouts (Mar 3), Cabbage (Mar 3), Lettuce (Mar 3), Sage (Mar 3), Swiss Chard (Mar 3), +14 more. Direct sow from: Arugula (Mar 3), Beets (Mar 3), Dill (Mar 3), Peas (Mar 3), Radish (Mar 3), Spinach (Mar 3), +3 more. Transplant from: Broccoli (Mar 31), Brussel Sprouts (Mar 31), Cabbage (Mar 31), Collards (Mar 31), Kale (Mar 31), Lettuce (Mar 31), +2 more. Plant: Strawberry (Mar 24). |
| April | Start indoors: Cucumber (Apr 7), Butternut Squash (Apr 14), Cantaloupe (Apr 14), Melons (Apr 14), Pumpkin (Apr 14), Spaghetti Squash (Apr 14), +3 more. Direct sow from: Carrots (Apr 7), Potatoes (Apr 14), Sunflowers (Apr 28). Transplant from: Calendula (Apr 14), Swiss Chard (Apr 14), Bok Choy (Apr 21), Cauliflower (Apr 21), Cosmos (Apr 28), Lavender (Apr 28), +4 more. Last frost around April 28. |
| May | Direct sow from: Beans (May 5), Pole Beans (May 5). Transplant from: Celery (May 5), Chives (May 5), Corn (May 5), Okra (May 5), Oregano (May 5), Parsley (May 5), +17 more. Last sowing dates: Butternut Squash (May 20), Pumpkin (May 20), Cantaloupe (May 28), Celery (May 28), Melons (May 28), Spaghetti Squash (May 30). |
| June | Last sowing dates: Tomato (Jun 2), Watermelon (Jun 2), Pepper (Jun 7), Tomatillos (Jun 7), Eggplant (Jun 12), Corn (Jun 14), +1 more. |
| July | Last sowing dates: Brussel Sprouts (Jul 1), Pole Beans (Jul 1), Basil (Jul 6), Cosmos (Jul 6), Cucumber (Jul 6), Zinnias (Jul 6), +12 more. |
| August | Last sowing dates: Beets (Aug 1), Dill (Aug 1), Swiss Chard (Aug 1), Calendula (Aug 6), Cilantro (Aug 6), Collards (Aug 10), +9 more. |
| September | First fall frost approaching (around October 2). Transplant fall brassicas. Sow spinach, arugula, and radishes. |
| October | Direct sow from: Garlic (Oct 2). First frost around October 2. Last sowing dates: Garlic (Oct 23). |
| November | Harvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year. |
| 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 Waterloo, IA (ZIP 50702)?
The median last spring frost date for Waterloo, IA (ZIP code 50702) is around April 28. 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 14; one in ten it runs past May 12.
What is the first fall frost date in Waterloo, IA?
The median first fall frost date for Waterloo, IA is around October 2. 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 20 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Waterloo, IA?
The frost-free growing season in Waterloo is about 157 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 Waterloo (157 frost-free days, a moderate season), 32 of 56 planner crops fit outright, 23 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Waterloo, IA?
Waterloo, IA is in USDA hardiness zone 5a (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 Waterloo, IA?
Start tomatoes indoors Mar 24 and plant out May 12 in Waterloo. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Waterloo?
Two: plant Mar 31 and again by Aug 11; both mature before Oct 9.
When do I plant garlic in Waterloo?
Oct 2 to Oct 23; it overwinters and is ready the following summer.
Which nearby ZIP has a longer season?
Marion (ZIP 52302) has 164 frost-free days, 7 more than Waterloo (ZIP 50702). See Marion ZIP 52302 frost dates
Nearby and related
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