Iowa County, WI — Planting Guide
Iowa County is in USDA Zone 4b. The average last spring frost is May 3 and the first fall frost is October 7, giving you a growing season of approximately 157 days.
At an elevation of 602 ft, Iowa County receives approximately 35.9 in of rainfall annually. Summer highs average 82°F with winter lows around 8°F. The predominant soil type is Silt Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 36 days year to year — ranging from April 15 in warm years to May 21 in cold years. Iowa County scores 76/100 (Good) on the Microclimate Index.
🌡️ Zone
4b (-25°F to -20°F min)
❄️ Last Frost
May 3
🍂 First Frost
October 7
📅 Growing Season
157 days
⛰️ Elevation
602 ft
🌧️ Annual Rainfall
35.9 in
Monthly Watering Calendar
When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering Effort |
|---|---|---|---|---|
| Jan | 1.4 in | 8 days | — | None |
| Feb | 1.7 in | 6 days | — | None |
| Mar | 3 in | 9 days | — | None |
| Apr | 3.5 in | 10 days | 0.8 in | Moderate |
| May | 4 in | 10 days | 0.3 in | Low |
| Jun | 4.1 in | 9 days | 0.2 in | Low |
| Jul | 3.7 in | 10 days | 0.6 in | Moderate |
| Aug | 3.6 in | 9 days | 0.7 in | Moderate |
| Sep | 3.5 in | 9 days | 0.8 in | Moderate |
| Oct | 2.7 in | 9 days | 1.6 in | High |
| Nov | 2.5 in | 8 days | — | None |
| Dec | 2.1 in | 8 days | — | None |
Annual total: 35.8 in. Gardens typically need ~1 inch of water per week during the growing season. Months marked "None" for extra water are outside the active growing season for your zone — most gardens are dormant and don't need irrigation during those months.
Iowa County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-7.1
Drainage
Well Drained
Frost Risk Probability
Based on 31 years of NOAA weather station data from 3 stations
Beginners: Plant frost-sensitive crops (tomatoes, peppers, squash) after the "Safe" date on the left. Harvest or cover them before the "Protect by" date on the right. Hardy crops (lettuce, peas, kale) can go in the yellow transition zones.
How to read this table: "Conservative" means you're safe from frost 9 out of 10 years — best for beginners and frost-sensitive crops. "Average year" is the typical date. "Aggressive" means only 1 in 10 years is that warm — experienced gardeners with frost protection can try these dates.
| Planting Strategy | Last Spring Frost | First Fall Frost | Frost-Free Days |
|---|---|---|---|
| Conservative (safest) | May 21 | Oct 16 | 148 days |
| Cautious | May 13 | Oct 12 | 152 days |
| Average year | May 3 | Oct 7 | 157 days |
| Optimistic | Apr 27 | Oct 2 | 158 days |
| Aggressive (risky) | Apr 15 | Sep 19 | 157 days |
Not very — frost dates can vary by ±36 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.
Gardening Difficulty Score
Iowa County offers good growing conditions. A little planning around frost dates goes a long way.
Local Gardening Help in Iowa County
Free expert help is closer than you think. Your county's cooperative extension office connects you with trained gardeners, soil testing labs, and local programs — all specific to Iowa County's climate and soil.
County Extension Office
Iowa County University of Wisconsin-Madison Division of Extension Extension Office
Phone: 608-263-7779
Visit Extension Office Website →
Extension offices are run by land-grant universities and funded by the USDA. Their advice is free, research-based, and tailored to your county's specific conditions.
Master Gardener Program
Free gardening help from trained volunteers
Master Gardeners are community volunteers who complete 40–60 hours of university horticultural training. They answer gardening questions, diagnose plant problems, and offer workshops — all free.
Many extension offices run a Master Gardener hotline where you can call or email with photos of plant problems for free diagnosis.
Soil Testing
Available through your extension office
Before amending your soil, get it tested. Your extension office offers soil testing (typically $10–$25) that tells you exact pH, nutrient levels, and amendment recommendations specific to what you want to grow.
Services Available in Iowa County
Finding local nurseries & garden centers in Iowa County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Iowa County's soil and climate that big-box stores can't. Plants from local growers are typically hardier because they're already acclimated to your zone.
How to Find Them
Search for "nurseries near Iowa County WI" or "garden center Iowa County" on Google Maps. Also check with your extension office — they often maintain lists of reputable local nurseries and plant sales.
Community gardens & gardening groups
Community gardens are a great way to learn from experienced gardeners in your area, especially if you're limited on space. Search "community garden Iowa County WI" or check your extension office and local parks department. Facebook groups like "Iowa County Gardeners" or "Wisconsin Gardening" are also excellent for local advice and plant swaps.
What to Plant After Your Harvest
After your first crops finish, use the remaining frost-free days to grow a second round.
Show 6 more succession options
Sunlight & Day Length
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
Longest Day
15.2 hours
Summer solstice daylight
Shortest Day
8.8 hours
Winter solstice daylight
Peak Sun Hours
9.5 hr/day peak (summer)
Peak sun hours (green dashed line below) account for cloud cover — this is the usable direct sunlight your garden actually receives. Most vegetables need 6+ peak sun hours.
Onion tip: Your long summer days (14+ hours) support long-day onion varieties like Walla Walla, Sweet Spanish, and Ailsa Craig.
View detailed monthly data
| Month | Daylight Hours | Peak Sun Hours | Day Length |
|---|---|---|---|
| January | 9.2 hr | 3.5 hr | Short day |
| February | 10.3 hr | 4.6 hr | Short day |
| March | 11.6 hr | 5.5 hr | Short day |
| April | 13.2 hr | 6.6 hr | Neutral |
| May | 14.5 hr | 8.7 hr | Long day |
| June | 15.2 hr | 9.4 hr | Long day |
| July | 14.9 hr | 9.5 hr | Long day |
| August | 13.8 hr | 8.8 hr | Neutral |
| September | 12.3 hr | 6.9 hr | Neutral |
| October | 10.8 hr | 5.5 hr | Short day |
| November | 9.5 hr | 3.6 hr | Short day |
| December | 8.8 hr | 3.3 hr | Short day |
Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.
Soil Temperature & Composting Calendar
Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.
Plant Warm Crops When
Soil reaches 60°F+
Soil warm enough from Jun through Sep.
Best Month to Compost
Jul
Microbial activity peaks when soil is warm.
Active Composting
6 months
Solid season. Piles go dormant in winter.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 13°F | 24°F | ❄️ Dormant | ~36 weeks |
| Feb | 16°F | 22°F | ❄️ Dormant | ~36 weeks |
| Mar | 28°F | 29°F | ❄️ Dormant | ~36 weeks |
| Apr | 41°F | 41°F | 🐢 Slow | ~24 weeks |
| May | 53°F | 50°F | ♻️ Active | ~14 weeks |
| Jun | 63°F | 59°F | ♻️ Active | ~14 weeks |
| Jul | 71°F | 68°F | 🔥 Peak | ~8 weeks |
| Aug | 72°F | 70°F | 🔥 Peak | ~8 weeks |
| Sep | 66°F | 66°F | 🔥 Peak | ~8 weeks |
| Oct | 51°F | 57°F | ♻️ Active | ~14 weeks |
| Nov | 37°F | 45°F | ❄️ Dormant | ~36 weeks |
| Dec | 22°F | 32°F | ❄️ Dormant | ~36 weeks |
Highlighted rows = soil 60°F+ (safe for warm-season transplants). Compost finishes fastest during peak activity months.
Pest & Disease Pressure in Iowa County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
Insect Pest Pressure
Moderate — common pests appear but manageable with monitoring.
Disease Risk
Moderate — watch for mildew and blight during wet periods.
Seasonal Risk
View 5 common pests in your area
| Pest | Risk Level | Peak Months |
|---|---|---|
| Aphids | Moderate | May, Jun, Jul, Aug |
| Cabbage worms | Low | Jun, Jul, Aug |
| Colorado potato beetle | Moderate | Jun, Jul |
| Flea beetles | Moderate | May, Jun, Jul |
| Slugs | Low | May, Jun, Jul, Aug, Sep |
Organic pest management tips
- Use row covers on susceptible crops during peak pest months
- Apply neem oil preventatively every 7-14 days during active pest season
- Interplant with strong-scented herbs (basil, marigold) to confuse pests
- Hand-pick larger pests (beetles, caterpillars) in early morning when they're sluggish
- Practice crop rotation — never plant the same family in the same spot within 3 years
Cover Crops for Iowa County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Fall Cover Crops (5 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Daikon radish | Aug 21 | Apr 19 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jul 30 | Apr 12 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Sep 1 | Apr 12 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jun 29 | Apr 12 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jul 16 | Apr 19 | — | Erosion control, weed suppression, good biomass |
Spring Cover Crops (2 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | May 3 | Aug 12 | — | Rapid growth, attracts pollinators, suppresses weeds |
| White clover | Apr 8 | Jul 29 | ✓ Yes | Living mulch, fixes nitrogen, permanent ground cover |
Summer Cover Crops (1 options) — Fill gaps and suppress weeds between plantings
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Sunflowers | May 29 | Sep 16 | — | Deep roots break compaction, attract pollinators and beneficial insects |
Wind & Microclimate
Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.
Seasonal Wind Speed
Spring: 11 mph Summer: 9 mph
Fall: 10 mph Winter: 11 mph
Prevailing wind: SW. Moderate wind — consider a temporary windbreak for young seedlings.
Windbreak Benefit
5.4/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
Low
Relatively flat terrain (192 ft range). Frost pocket risk is minimal — garden placement is flexible.
Rainwater Harvesting Potential
How much water you can collect, when to collect it, and what size system you need for your garden.
Annual Collection
17,842 gal
Per 1,000 sq ft of roof area (at 80% collection efficiency)
Recommended Setup
6 rain barrels (55 gal each)
For a typical 500 sq ft garden. Serious collectors: consider a 1,500 gal tank.
Legal Status
Unrestricted
Rainwater harvesting is fully legal in your state with no restrictions.
Best Collection Months
May, Jun, Jul, Aug
Highest rainfall months — your barrels will fill up quickly during these months.
Months to Draw From Storage
Jan, Feb, Dec
Dry months when you'll rely on stored water — size your storage for this gap.
Rainwater collection tips for your area
- Your county receives approximately 35.8 inches of rain per year
- A 1,000 sq ft roof can collect roughly 17,842 gallons annually
- Rainwater harvesting is fully legal in your state
- Stock up on stored water before your dry season (Jan, Feb, Dec)
- Use a first-flush diverter to keep roof debris out of your collection
Soil & Growing Conditions in Iowa County
Soil Type
Silt Loam
Soil pH 5.8–7.1 · Well Drained drainage
Native soil is well-suited to most vegetables and herbs with regular compost additions.
Watering Needs
Drought stress: 3.5/10
Low-to-moderate drought stress. Plan to water 1–2 times per week during peak summer. (35.9 in. annual rainfall)
Season Tips
157-day frost-free season
Start warm-season crops indoors and focus on short-season varieties. Cold frames extend your season by 3–4 weeks in fall.
Free Garden Planner
Plan your entire garden season — organize planting dates, track what you're growing, and know exactly when to start seeds, transplant, and harvest.
Recommended for Your Garden
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Get instant, accurate soil pH readings to fine-tune your amendments.
Boost soil fertility and structure with rich, well-aged organic compost.
🥬 Vegetables to Grow in Iowa County
96 vegetables that grow well in Zone 4b with planting dates for Iowa County.
Show all 96 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Mar 22 | May 17 | May 24 | Aug 16 – Sep 20 | 80–100 |
| Amaranth | Mar 1 | May 17 | May 24 | Aug 23 – Oct 11 | 90–120 |
| Arugula | Mar 22 | Apr 26 | May 3 | Jun 7 – Aug 9 | 30–50 |
| Asparagus | — | — | May 17 | — | 730–1095 |
| Beets | — | Apr 26 | — | Jun 21 – Jul 19 | 50–70 |
| Belgian Endive | Mar 22 | Apr 26 | May 3 | Aug 23 – Sep 27 | 110–150 |
| Black Beans | — | May 17 | — | Aug 16 – Oct 4 | 90–120 |
| Bok Choy | Mar 22 | Apr 26 | May 3 | Jun 14 – Jul 19 | 40–60 |
| Broccoli | Mar 22 | Apr 26 | May 3 | Jul 5 – Aug 16 | 60–90 |
| Broccoli Rabe | Mar 22 | Apr 26 | May 3 | Jun 14 – Jul 19 | 40–60 |
| Brussels Sprouts | Mar 22 | Apr 26 | May 3 | Aug 2 – Sep 27 | 90–130 |
| Butternut Squash | Mar 22 | May 17 | May 24 | Aug 23 – Sep 27 | 85–110 |
| Cabbage | Mar 22 | Apr 26 | May 3 | Jul 5 – Aug 30 | 60–100 |
| Carrots | — | Apr 26 | — | Jun 28 – Aug 2 | 60–80 |
| Cauliflower | Mar 22 | Apr 26 | May 3 | Jun 28 – Aug 30 | 55–100 |
| Celeriac | Mar 22 | Apr 26 | May 3 | Aug 16 – Sep 20 | 100–120 |
| Celery | Mar 22 | Apr 26 | May 3 | Jul 26 – Sep 20 | 80–120 |
| Celtuce | Mar 22 | Apr 26 | May 3 | Jul 5 – Aug 16 | 60–90 |
| Chard | Mar 22 | Apr 26 | May 3 | Jun 28 – Aug 16 | 50–60 |
| Chickpeas | Mar 22 | Apr 26 | May 3 | Jul 26 – Sep 6 | 80–110 |
| Chicory | Mar 22 | Apr 26 | May 3 | Jul 5 – Aug 16 | 60–85 |
| Chinese Cabbage | Mar 22 | Apr 26 | May 3 | Jun 28 – Jul 26 | 50–70 |
| Christmas Lima Beans | Mar 1 | May 17 | May 24 | Aug 16 – Sep 20 | 80–100 |
| Collard Greens | Mar 22 | Apr 26 | May 3 | Jun 28 – Aug 30 | 55–75 |
| Corn | — | May 17 | — | Jul 19 – Sep 13 | 60–100 |
| Cress | Mar 22 | Apr 26 | May 3 | May 17 – Jun 7 | 14–21 |
| Crookneck Squash | Mar 22 | May 17 | May 24 | Jul 12 – Aug 9 | 45–60 |
| Crosne | — | Apr 26 | — | Sep 27 – Sep 20 | 150–200 |
| Cucumber | Mar 22 | May 17 | May 24 | Jul 19 – Sep 13 | 50–70 |
| Daikon | — | Apr 26 | — | Jun 21 – Jul 19 | 50–70 |
| Delicata Squash | Mar 22 | May 17 | May 24 | Aug 16 – Sep 20 | 80–100 |
| Edamame | — | May 17 | — | Aug 2 – Sep 13 | 75–100 |
| Endive | Mar 22 | Apr 26 | May 3 | Jun 21 – Jul 26 | 45–65 |
| Escarole | Mar 22 | Apr 26 | May 3 | Jun 28 – Jul 26 | 50–70 |
| Fava Beans | Mar 22 | Apr 26 | May 3 | Jul 19 – Aug 30 | 75–100 |
| Fennel | Mar 1 | May 17 | May 24 | Jul 26 – Sep 6 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | May 17 | — | Jul 12 – Sep 6 | 50–65 |
| Horseradish | — | — | May 17 | Sep 20 – Oct 11 | 120–180 |
| Hubbard Squash | Mar 22 | May 17 | May 24 | Sep 6 – Oct 11 | 100–120 |
| Kabocha | Mar 22 | May 17 | May 24 | Aug 23 – Sep 20 | 85–100 |
| Kai Lan | Mar 22 | Apr 26 | May 3 | Jun 21 – Jul 19 | 45–60 |
| Kale | Mar 22 | Apr 26 | May 3 | Jun 28 – Aug 23 | 50–70 |
| Kidney Beans | — | May 17 | — | Aug 16 – Sep 20 | 85–110 |
| Kohlrabi | Mar 22 | Apr 26 | May 3 | Jun 21 – Jul 26 | 45–65 |
| Komatsuna | Mar 22 | Apr 26 | May 3 | Jun 7 – Jul 12 | 35–50 |
| Leeks | Mar 22 | Apr 26 | May 3 | Aug 2 – Sep 27 | 90–150 |
| Lentils | Mar 22 | Apr 26 | May 3 | Jul 26 – Sep 6 | 80–110 |
| Lettuce | Mar 22 | Apr 26 | May 3 | Jun 7 – Aug 16 | 30–60 |
| Lima Beans | — | May 17 | — | Jul 19 – Aug 30 | 60–90 |
| Mache | Mar 22 | Apr 26 | May 3 | Jun 14 – Jul 19 | 40–60 |
| Melon | Mar 22 | May 17 | May 24 | Aug 2 – Sep 20 | 70–100 |
| Microgreens | Mar 22 | Apr 26 | May 3 | May 10 – Jun 7 | 7–21 |
| Mitsuba | Mar 22 | Apr 26 | Apr 26 | Jun 21 – Aug 16 | 50–70 |
| Mizuna | Mar 22 | Apr 26 | May 3 | Jun 7 – Jul 5 | 30–45 |
| Mustard Greens | Mar 22 | Apr 26 | May 3 | Jun 7 – Aug 9 | 30–50 |
| Napa Cabbage | Mar 22 | Apr 26 | May 3 | Jun 28 – Aug 2 | 55–75 |
| Onion | Mar 22 | Apr 26 | May 3 | Aug 2 – Sep 20 | 90–120 |
| Pac Choi | Mar 22 | Apr 26 | May 3 | Jun 14 – Jul 12 | 40–55 |
| Parsnip | — | Apr 26 | — | Aug 9 – Sep 20 | 100–130 |
| Patty Pan Squash | Mar 22 | May 17 | May 24 | Jul 12 – Aug 9 | 45–60 |
| Peas | Mar 22 | Apr 26 | May 3 | Jun 28 – Aug 23 | 55–70 |
| Peppers | Feb 15 | May 17 | May 24 | Jul 26 – Oct 4 | 60–90 |
| Pole Beans | Mar 1 | May 17 | May 24 | Jul 19 – Sep 13 | 55–70 |
| Potatoes | Mar 1 | May 17 | May 24 | Aug 2 – Oct 11 | 70–120 |
| Pumpkin | Mar 22 | May 17 | May 24 | Aug 23 – Oct 11 | 85–120 |
| Purslane | Mar 22 | Apr 26 | May 3 | Jun 14 – Jul 19 | 40–60 |
| Radicchio | Mar 22 | Apr 26 | May 3 | Jul 5 – Aug 9 | 60–80 |
| Radish | — | Apr 26 | — | May 24 – Jun 14 | 22–35 |
| Rhubarb | — | — | May 31 | — | 365–730 |
| Romanesco | Mar 22 | Apr 26 | May 3 | Jul 19 – Aug 30 | 75–100 |
| Rutabaga | — | Apr 26 | — | Jul 19 – Aug 23 | 80–100 |
| Salsify | — | Apr 26 | — | Aug 9 – Sep 20 | 100–130 |
| Savoy Cabbage | Mar 22 | Apr 26 | May 3 | Jul 12 – Sep 6 | 70–110 |
| Scallions | Mar 22 | Apr 26 | May 3 | Jun 28 – Jul 26 | 50–70 |
| Scarlet Runner Beans | Mar 1 | May 17 | May 24 | Jul 26 – Aug 30 | 60–80 |
| Shallot | Mar 22 | Apr 26 | May 3 | Aug 2 – Sep 20 | 90–120 |
| Shiso | Mar 8 | May 10 | May 24 | Jul 19 – Sep 13 | 50–70 |
| Snap Peas | Mar 1 | May 17 | May 24 | Jul 19 – Sep 13 | 55–70 |
| Snow Peas | Mar 22 | Apr 26 | May 3 | Jun 28 – Aug 23 | 50–65 |
| Soybeans | — | May 17 | — | Aug 9 – Oct 4 | 80–120 |
| Spaghetti Squash | Mar 22 | May 17 | May 24 | Aug 23 – Sep 20 | 85–100 |
| Spinach | Mar 22 | Apr 26 | May 3 | Jun 7 – Aug 9 | 35–50 |
| Squash (Summer) | Mar 22 | May 17 | May 24 | Jul 12 – Sep 13 | 45–65 |
| Squash (Winter) | Mar 22 | May 17 | May 24 | Aug 16 – Oct 11 | 80–120 |
| Sunchoke | — | — | May 17 | Sep 6 – Oct 11 | 110–150 |
| Sunflower | Mar 1 | May 17 | May 24 | Aug 2 – Sep 20 | 70–100 |
| Sweet Corn | — | May 17 | — | Jul 19 – Aug 30 | 60–90 |
| Tatsoi | Mar 22 | Apr 26 | May 3 | Jun 7 – Jul 12 | 35–50 |
| Tomatillo | Mar 1 | May 17 | May 24 | Jul 26 – Oct 4 | 60–85 |
| Tomatoes | Mar 1 | May 17 | May 24 | Jul 26 – Oct 4 | 60–85 |
| Turnip | — | Apr 26 | — | Jun 7 – Jul 12 | 40–60 |
| Watercress | Mar 22 | Apr 26 | May 3 | Jun 14 – Jul 19 | 40–60 |
| Watermelon | Mar 22 | May 17 | May 24 | Aug 2 – Sep 20 | 70–100 |
| Wax Beans | — | May 17 | — | Jul 12 – Sep 6 | 50–65 |
| Zucchini | Mar 22 | May 17 | May 24 | Jul 12 – Sep 6 | 45–60 |
🍓 Fruits to Grow in Iowa County
22 fruits that grow well in Zone 4b with planting dates for Iowa County.
Show all 22 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | May 31 | Aug 30 – Oct 25 | 90–180 |
| Aronia | — | — | May 31 | — | 730–1095 |
| Blueberries | — | — | May 31 | — | 730–1095 |
| Cantaloupe | — | — | May 31 | Aug 9 – Sep 13 | 70–90 |
| Cranberries | — | — | May 31 | — | 730–1095 |
| Currants | — | — | May 31 | — | 730–1095 |
| Elderberries | — | — | May 31 | — | 730–1095 |
| Goji Berries | — | — | May 31 | — | 730–1095 |
| Gooseberries | — | — | May 31 | — | 730–1095 |
| Grapes | — | — | May 31 | — | 730–1095 |
| Ground Cherry | — | — | May 31 | Aug 9 – Oct 4 | 65–80 |
| Hardy Kiwi | — | — | May 31 | — | 1095–1825 |
| Haskaps | — | — | May 31 | — | 730–1095 |
| Honeydew | — | — | May 31 | Aug 23 – Oct 4 | 80–110 |
| Jostaberry | — | — | May 31 | — | 730–1095 |
| Lingonberries | — | — | May 31 | — | 730–1095 |
| Medlar | — | — | May 31 | — | 1095–1825 |
| Mulberries | — | — | May 31 | — | 730–1825 |
| Persimmon | — | — | May 31 | — | 1095–2555 |
| Raspberries | — | — | May 31 | — | 365–730 |
| Serviceberries | — | — | May 31 | — | 730–1095 |
| Strawberries | — | — | May 31 | Aug 30 – Oct 25 | 90–365 |
🌿 Herbs to Grow in Iowa County
32 herbs that grow well in Zone 4b with planting dates for Iowa County.
Show all 32 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Mar 22 | Apr 26 | Apr 26 | — | 365–730 |
| Anise | Mar 22 | Apr 26 | Apr 26 | Jul 26 – Sep 20 | 90–120 |
| Basil | Mar 8 | May 10 | May 24 | Jul 19 – Sep 20 | 50–75 |
| Bee Balm | — | — | May 10 | Aug 9 – Oct 4 | 90–120 |
| Borage | Mar 22 | Apr 26 | Apr 26 | Jun 21 – Aug 9 | 50–60 |
| Caraway | Mar 22 | Apr 26 | Apr 26 | — | 365–450 |
| Catnip | — | — | May 10 | Jul 12 – Sep 13 | 60–80 |
| Chamomile | Mar 22 | Apr 26 | Apr 26 | Jun 28 – Sep 6 | 60–90 |
| Chervil | Mar 22 | Apr 26 | Apr 26 | Jun 7 – Aug 9 | 40–60 |
| Chives | — | — | May 10 | Jul 12 – Sep 20 | 60–90 |
| Cilantro | Mar 22 | Apr 26 | Apr 26 | Jun 7 – Aug 9 | 40–60 |
| Comfrey | — | — | May 10 | Jul 12 – Sep 20 | 60–90 |
| Dill | Mar 22 | Apr 26 | Apr 26 | Jun 7 – Aug 9 | 40–60 |
| Echinacea | — | — | May 10 | Sep 13 – Oct 4 | 120–180 |
| Fennel (herb) | Mar 22 | Apr 26 | Apr 26 | Jun 28 – Sep 6 | 60–90 |
| Garlic Chives | — | — | May 10 | Jul 12 – Sep 20 | 60–90 |
| Horehound | — | — | May 10 | Jul 26 – Sep 20 | 75–90 |
| Hyssop | — | — | May 10 | Jul 19 – Sep 20 | 70–90 |
| Lemon Balm | — | — | May 10 | Jul 12 – Aug 30 | 60–70 |
| Lovage | — | — | May 10 | Jul 19 – Sep 20 | 70–90 |
| Mint | — | — | May 10 | Jul 12 – Sep 20 | 60–90 |
| Oregano | — | — | May 10 | Jul 12 – Sep 20 | 60–90 |
| Parsley | Mar 22 | Apr 26 | Apr 26 | Jun 28 – Aug 30 | 60–80 |
| Rue | — | — | May 10 | Jul 19 – Sep 20 | 70–90 |
| Sage | — | — | May 10 | Jul 26 – Sep 20 | 75–90 |
| Savory | — | — | May 10 | Jul 5 – Aug 30 | 50–70 |
| Sorrel | Mar 22 | Apr 26 | Apr 26 | Jun 7 – Aug 9 | 40–60 |
| Tarragon | — | — | May 10 | Jul 12 – Sep 20 | 60–90 |
| Thai Basil | Mar 8 | May 10 | May 24 | Jul 19 – Sep 20 | 50–75 |
| Thyme | — | — | May 10 | Jul 19 – Sep 20 | 70–90 |
| Valerian | — | — | May 10 | Sep 13 – Oct 4 | 120–180 |
| Yarrow | — | — | May 10 | Aug 9 – Oct 4 | 90–120 |
Monthly Planting Guide for Iowa County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Iowa County.
Frequently Asked Questions
What planting zone is Iowa County, WI?
Iowa County is in USDA Hardiness Zone 4b. This zone classification determines which perennial plants survive winter and sets the baseline for frost timing across the county.
When is the last frost in Iowa County, WI?
Based on 31 years of NOAA weather station data, the median last spring frost in Iowa County falls around May 3. In 8 out of 10 years, last frost lands between April 15 and May 21 — a 36-day window of variability. Use May 21 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Iowa County, WI?
The median first fall frost in Iowa County arrives around October 7. In cold years it can arrive as early as September 19; in mild years as late as October 16. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Iowa County?
Iowa County has a frost-free growing season of approximately 157 days. This is enough time for most warm-season crops including tomatoes, peppers, and squash with proper timing.
What is the soil like in Iowa County for gardening?
Iowa County has predominantly Silt Loam soil with a pH range of 5.8–7.1 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Iowa County?
Iowa County has commercial agriculture that includes Corn, Soybeans, Hay, Dairy. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Iowa County a good location for home gardening?
Iowa County scores 76/100 (Good) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. This is an above-average location for home gardening with relatively predictable growing conditions.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Iowa County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.
