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Portage County, WI — Planting Guide

Portage County, Wisconsin Zone 4b July

Your July gardening checklist

Here's what deserves your attention in Portage County, Wisconsin this month. Everything below is tailored to Zone 4b and timed around your local frost dates.

Avg. last frost May 5
Avg. first frost October 6
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 15 hrs
  1. Start peppers, pole beans, and tomatoes under lights

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Start harvesting basil, carrots, and cucumber

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

  3. Direct-sow carrots, kale, and lettuce for cool weather

    A row cover ready in the garage extends your harvest by weeks once the nights turn cold.

August prep starts now
  • First harvests: basil, carrots, and cucumber
  • Fall sowing: alliums, crocus, and daffodils

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Portage County is in USDA Zone 4b. The average last spring frost is May 5 and the first fall frost is October 6, giving you a growing season of approximately 154 days.

At an elevation of 1,008 ft, Portage County receives approximately 37.6 in of rainfall annually. The predominant soil type is Silt Loam.

Based on 31 years of NOAA climate station data, the last frost date here varies by 27 days year to year — ranging from April 22 in warm years to May 19 in cold years. Portage County scores 73/100 (Good) on the Microclimate Index.

🌡️ Zone

4b (-25°F to -20°F min)

❄️ Last Frost

May 5

🍂 First Frost

October 6

📅 Growing Season

154 days

⛰️ Elevation

1,008 ft

🌧️ Annual Rainfall

37.6 in

Portage County, WI Moderate season
154 days
Last Spring Frost May 5
154 growing days
First Fall Frost October 6

Monthly Watering Calendar for Portage County

When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.

Quick context: In humid climates, watering is usually about timing (morning, not evening, to prevent disease) more than volume. In dry climates, it's about depth (water deep, less often) more than frequency. Portage County's 38" annual tells you which side you're on.

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 1.5" Feb 1.6" Mar 2.5" +1.2" Apr 3.1" May 4.1" Jun 4.9" Jul 4" Aug 4.5" +0.8" Sep 3.5" +1.5" Oct 2.8" Nov 2.7" Dec 2.4"
Rainfall sufficient Supplemental water needed Heavy watering required - - - 1"/week garden need
View detailed monthly data
MonthAvg RainfallRainy DaysExtra Water NeededWatering Effort
Jan 1.5 in 8 days None
Feb 1.6 in 6 days None
Mar 2.5 in 9 days None
Apr 3.1 in 10 days 1.2 in Moderate
May 4.1 in 11 days 0.2 in Low
Jun 4.9 in 9 days Low
Jul 4 in 9 days 0.3 in Low
Aug 4.5 in 8 days Low
Sep 3.5 in 7 days 0.8 in Moderate
Oct 2.8 in 8 days 1.5 in Moderate
Nov 2.7 in 8 days None
Dec 2.4 in 7 days None

Annual total: 37.6 in. Water needs vary by crop — tomatoes need ~1.2"/week while herbs like rosemary need only 0.3"/week. Check individual plant pages for crop-specific water budgets that factor in your county's rainfall and soil drainage.

Portage County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.1

Drainage

Well Drained

Frost Risk Probability

Based on 31 years of NOAA weather station data from 3 stations

Too early frost risk Safe to Plant May 5 → Oct 6 154 frost-free days Protect crops frost returns Apr May Jun Jul Aug Sep Oct Nov Safe: May 19 Protect by: Oct 19

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 19 Oct 19 153 days
Cautious May 12 Oct 13 154 days
Average year May 5 Oct 6 154 days
Optimistic Apr 28 Oct 3 158 days
Aggressive (risky) Apr 22 Sep 23 154 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±27 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.

Gardening Difficulty Score

73 Good
Frost Timing Risk
10.0/10
Drought Risk
5.5/10
Soil Difficulty
0.0/10
Altitude Challenge
0.0/10
Climate Shift
0.6/10
Rainfall Challenge
0.0/10

Portage County offers good growing conditions. A little planning around frost dates goes a long way.

Zone 4b Frost Countdown
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Loading...
Last Frost: May 5 First Frost: Oct 6

Local Gardening Help in Portage 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 Portage County's climate and soil.

County Extension Office

Portage 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.

Find Master Gardeners in WI →

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.

Request a Soil Test →

Services Available in Portage County

Soil testing Pest diagnostics Master Gardener program
Finding local nurseries & garden centers in Portage County

Why Buy Local

Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Portage 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 Portage County WI" or "garden center Portage 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 Portage County WI" or check your extension office and local parks department. Facebook groups like "Portage 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
After Carrots (harvest ends Aug 11) 56 days until frost
After Cauliflower (harvest ends Sep 1) 35 days until frost
After Lettuce (harvest ends Aug 18) 49 days until frost
After Beets (harvest ends Jul 28) 70 days until frost
After Peas (harvest ends Aug 25) 42 days until frost
After Green Beans (harvest ends Aug 25) 42 days until frost

Sunlight & Day Length in Portage County

Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.

Quick context: Day length triggers flowering in many crops. Some need short days (sweet potatoes), some long (most flowers), and some are day-neutral (most modern tomatoes). Portage County's latitude determines which varieties fit your beds.

Longest Day

15.3 hours

Summer solstice daylight

Shortest Day

8.7 hours

Winter solstice daylight

Peak Sun Hours

9.6 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.

14hr 12hr 2h 6h 10h 13h 17h Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Daylight hours (sunrise to sunset) Peak sun hours (direct sunlight after cloud cover) ▪ Gold zone = long day (14+ hr) ▪ Blue zone = short day (<12 hr)

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
MonthDaylight HoursPeak Sun HoursDay Length
January 9 hr 3.5 hr Short day
February 10.2 hr 4.6 hr Short day
March 11.6 hr 5.4 hr Short day
April 13.2 hr 6.6 hr Neutral
May 14.6 hr 8.4 hr Long day
June 15.3 hr 9.6 hr Long day
July 15 hr 9.3 hr Long day
August 13.9 hr 8.8 hr Neutral
September 12.3 hr 7 hr Neutral
October 10.7 hr 5.6 hr Short day
November 9.3 hr 3.8 hr Short day
December 8.7 hr 3.2 hr Short day

Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.

Soil Temperature & Composting in Portage County

Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.

Quick context: Soil temperature predicts plant emergence better than calendar dates. Portage County's spring soil warm-up curve tells you which weeks are safe for direct-sow beans, cucumbers, squash, and corn.

Plant Warm Crops When

Soil reaches 60°F+

Soil warm enough from Jun through Sep.

Best Month to Compost

Jun

Microbial activity peaks when soil is warm.

Active Composting

6 months

Solid season. Piles go dormant in winter.

60°F 70°F 23° 45° 68° 90° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
4" depth 8" depth - - - 60°F (corn, beans) - - - 70°F (tomatoes, peppers)
View detailed monthly data
MonthSoil 4" DeepSoil 8" DeepCompost ActivityTime to Finish
Jan 14°F 24°F ❄️ Dormant ~36 weeks
Feb 16°F 22°F ❄️ Dormant ~36 weeks
Mar 26°F 29°F ❄️ Dormant ~36 weeks
Apr 39°F 40°F ❄️ Dormant ~36 weeks
May 54°F 51°F ♻️ Active ~14 weeks
Jun 66°F 59°F 🔥 Peak ~8 weeks
Jul 72°F 67°F 🔥 Peak ~8 weeks
Aug 76°F 68°F 🔥 Peak ~8 weeks
Sep 67°F 63°F 🔥 Peak ~8 weeks
Oct 52°F 55°F ♻️ Active ~14 weeks
Nov 38°F 44°F ❄️ Dormant ~36 weeks
Dec 24°F 31°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 Portage County

Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.

Quick context: High pest pressure means weekly inspection. Low pest pressure means monthly. The score tells you which routine to set up before you have a problem.

Insect Pest Pressure

5 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

5.7 / 10

Moderate — watch for mildew and blight during wet periods.

Seasonal Risk

Spring Low
Summer High
Fall Low
Winter Low
View 5 common pests in your area
PestRisk LevelPeak Months
Aphids Moderate May, Jun, Jul, Aug
Cabbage worms Low Jun, Jul, Aug
Colorado potato beetle Low 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 Portage County

Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with planting dates calibrated for your area.

Why this matters: The "chop and drop" approach to cover crops: cut them down right before flowering, let them lay on the surface as mulch, plant your vegetables through the mulch. Less work, healthier soil.

Spring Cover Crops (2 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat May 10 Aug 4 Rapid growth, attracts pollinators, suppresses weeds
White clover Apr 5 Jul 28 ✓ 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 27 Sep 15 Deep roots break compaction, attract pollinators and beneficial insects
Fall Cover Crops (5 options) — Plant after harvest to protect soil over winter
Crop Plant By Terminate N-Fixing Soil Benefit
Daikon radish Aug 13 Apr 14 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Jul 28 Apr 14 ✓ Yes Excellent nitrogen fixer, good for depleted soils
Oats Aug 25 Apr 14 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jun 29 Apr 14 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jun 30 Apr 21 Erosion control, weed suppression, good biomass

Wind & Microclimate in Portage County

Why this matters: Why care about wind? Above about 10 mph, evaporation jumps and pollinators struggle to land on flowers. Portage County's 9.3 mph average means you can plant tall crops without much support, but it doesn't mean ignore wind — a 20+ mph storm still snaps unstaked tomatoes.

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: 9 mph   Winter: 11 mph

Prevailing wind: SW. Moderate wind — consider a temporary windbreak for young seedlings.

Windbreak Benefit

4.9/10

Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.

Frost Pocket Risk

Low

Relatively flat terrain (203 ft range). Frost pocket risk is minimal — garden placement is flexible.

Rainwater Harvesting in Portage County

How much water you can collect, when to collect it, and what size system you need for your garden.

The practical takeaway: Building a rainwater system is mostly about doing the math: roof area × annual rainfall × 0.6 = gallons you could realistically capture. For Portage County, that's your 38" times your roof.

Annual Collection

18,739 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 37.6 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 18,739 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 Portage County

Soil Type

Silt Loam

Soil pH 5.9–7.1 · Excessively Drained drainage

Native soil is well-suited to most vegetables and herbs with regular compost additions.

Watering Needs

Drought stress: 5.5/10

Moderate drought pressure. Drip irrigation and mulching are highly recommended to maintain soil moisture through summer.

Season Tips

154-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.

Your Free Printable Garden Planner

Plan every bed, every planting, every harvest — in one place. This 22-page printable includes your zone's planting calendar, a month-by-month task list, a seed inventory tracker, a harvest log, and succession-planting charts. Built to print, write in, and actually use all season.

Instant PDF download. No spam, unsubscribe any time.

Recommended for Your Garden

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

📏
Digital pH Meter $10-20

Get instant, accurate soil pH readings to fine-tune your amendments.

🍂
Organic Compost $8-30

Boost soil fertility and structure with rich, well-aged organic compost.

🥬 Vegetables to Grow in Portage County

95 vegetables that grow well in Zone 4b with planting dates for Portage County.

Show all 95 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Acorn Squash Mar 24 May 19 May 26 Aug 18 – Sep 22 80–100
Amaranth Mar 3 May 19 May 26 Aug 25 – Oct 13 90–120
Arugula Mar 24 Apr 28 May 5 Jul 14 Jun 9 – Aug 11 30–50
Asparagus May 19 730–1095
Beets Apr 28 Jul 14 Jun 23 – Jul 21 50–70
Belgian Endive Mar 24 Apr 28 May 5 Jul 14 Aug 25 – Sep 29 110–150
Black Beans May 19 Aug 18 – Oct 6 90–120
Bok Choy Mar 24 Apr 28 May 5 Jul 14 Jun 16 – Jul 21 40–60
Broccoli Mar 24 Apr 28 May 5 Jul 14 Jul 7 – Aug 18 60–90
Broccoli Rabe Mar 24 Apr 28 May 5 Jul 14 Jun 16 – Jul 21 40–60
Brussels Sprouts Mar 24 Apr 28 May 5 Jul 14 Aug 4 – Sep 29 90–130
Butternut Squash Mar 24 May 19 May 26 Aug 25 – Sep 29 85–110
Cabbage Mar 24 Apr 28 May 5 Jul 14 Jul 7 – Sep 1 60–100
Carrots Apr 28 Jul 14 Jun 30 – Aug 4 60–80
Cauliflower Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Sep 1 55–100
Celeriac Mar 24 Apr 28 May 5 Jul 14 Aug 18 – Sep 22 100–120
Celery Mar 24 Apr 28 May 5 Jul 14 Jul 28 – Sep 22 80–120
Celtuce Mar 24 Apr 28 May 5 Jul 14 Jul 7 – Aug 18 60–90
Chard Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Aug 18 50–60
Chickpeas Mar 24 Apr 28 May 5 Jul 14 Jul 28 – Sep 8 80–110
Chicory Mar 24 Apr 28 May 5 Jul 14 Jul 7 – Aug 18 60–85
Chinese Cabbage Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Jul 28 50–70
Christmas Lima Beans Mar 3 May 19 May 26 Aug 18 – Sep 22 80–100
Collard Greens Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Sep 1 55–75
Corn May 19 Jul 21 – Sep 15 60–100
Cress Mar 24 Apr 28 May 5 Jul 14 May 19 – Jun 9 14–21
Crookneck Squash Mar 24 May 19 May 26 Jul 14 – Aug 11 45–60
Crosne Apr 28 Jul 14 Sep 29 – Sep 22 150–200
Cucumber Mar 24 May 19 May 26 Jul 21 – Sep 15 50–70
Daikon Apr 28 Jul 14 Jun 23 – Jul 21 50–70
Delicata Squash Mar 24 May 19 May 26 Aug 18 – Sep 22 80–100
Edamame May 19 Aug 4 – Sep 15 75–100
Endive Mar 24 Apr 28 May 5 Jul 14 Jun 23 – Jul 28 45–65
Escarole Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Jul 28 50–70
Fava Beans Mar 24 Apr 28 May 5 Jul 14 Jul 21 – Sep 1 75–100
Fennel Mar 3 May 19 May 26 Jul 28 – Sep 8 60–90
Garlic Aug 25 Nov 24 – Jan 19 90–240
Green Beans May 19 Jul 14 – Sep 8 50–65
Horseradish May 19 Sep 22 – Oct 13 120–180
Hubbard Squash Mar 24 May 19 May 26 Sep 8 – Oct 13 100–120
Kabocha Mar 24 May 19 May 26 Aug 25 – Sep 22 85–100
Kai Lan Mar 24 Apr 28 May 5 Jul 14 Jun 23 – Jul 21 45–60
Kale Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Aug 25 50–70
Kidney Beans May 19 Aug 18 – Sep 22 85–110
Kohlrabi Mar 24 Apr 28 May 5 Jul 14 Jun 23 – Jul 28 45–65
Komatsuna Mar 24 Apr 28 May 5 Jul 14 Jun 9 – Jul 14 35–50
Leeks Mar 24 Apr 28 May 5 Jul 14 Aug 4 – Sep 29 90–150
Lentils Mar 24 Apr 28 May 5 Jul 14 Jul 28 – Sep 8 80–110
Lettuce Mar 24 Apr 28 May 5 Jul 14 Jun 9 – Aug 18 30–60
Lima Beans May 19 Jul 21 – Sep 1 60–90
Mache Mar 24 Apr 28 May 5 Jul 14 Jun 16 – Jul 21 40–60
Melon Mar 24 May 19 May 26 Aug 4 – Sep 22 70–100
Microgreens Mar 24 Apr 28 May 5 Jul 14 May 12 – Jun 9 7–21
Mitsuba Mar 24 Apr 28 Apr 28 Jul 14 Jun 23 – Aug 18 50–70
Mizuna Mar 24 Apr 28 May 5 Jul 14 Jun 9 – Jul 7 30–45
Mustard Greens Mar 24 Apr 28 May 5 Jul 14 Jun 9 – Aug 11 30–50
Napa Cabbage Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Aug 4 55–75
Onion Mar 24 Apr 28 May 5 Jul 14 Aug 4 – Sep 22 90–120
Pac Choi Mar 24 Apr 28 May 5 Jul 14 Jun 16 – Jul 14 40–55
Parsnip Apr 28 Jul 14 Aug 11 – Sep 22 100–130
Patty Pan Squash Mar 24 May 19 May 26 Jul 14 – Aug 11 45–60
Peas Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Aug 25 55–70
Peppers Feb 17 May 19 May 26 Jul 28 – Oct 6 60–90
Pole Beans Mar 3 May 19 May 26 Jul 21 – Sep 15 55–70
Potatoes Mar 3 May 19 May 26 Aug 4 – Oct 13 70–120
Pumpkin Mar 24 May 19 May 26 Aug 25 – Oct 13 85–120
Purslane Mar 24 Apr 28 May 5 Jul 14 Jun 16 – Jul 21 40–60
Radicchio Mar 24 Apr 28 May 5 Jul 14 Jul 7 – Aug 11 60–80
Radish Apr 28 Jul 14 May 26 – Jun 16 22–35
Rhubarb Jun 2 365–730
Romanesco Mar 24 Apr 28 May 5 Jul 14 Jul 21 – Sep 1 75–100
Rutabaga Apr 28 Jul 14 Jul 21 – Aug 25 80–100
Salsify Apr 28 Jul 14 Aug 11 – Sep 22 100–130
Savoy Cabbage Mar 24 Apr 28 May 5 Jul 14 Jul 14 – Sep 8 70–110
Scallions Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Jul 28 50–70
Scarlet Runner Beans Mar 3 May 19 May 26 Jul 28 – Sep 1 60–80
Shallot Mar 24 Apr 28 May 5 Jul 14 Aug 4 – Sep 22 90–120
Shiso Mar 10 May 12 May 26 Jul 21 – Sep 15 50–70
Snap Peas Mar 3 May 19 May 26 Jul 21 – Sep 15 55–70
Snow Peas Mar 24 Apr 28 May 5 Jul 14 Jun 30 – Aug 25 50–65
Soybeans May 19 Aug 11 – Oct 6 80–120
Spaghetti Squash Mar 24 May 19 May 26 Aug 25 – Sep 22 85–100
Spinach Mar 24 Apr 28 May 5 Jul 14 Jun 9 – Aug 11 35–50
Squash (Summer) Mar 24 May 19 May 26 Jul 14 – Sep 15 45–65
Squash (Winter) Mar 24 May 19 May 26 Aug 18 – Oct 13 80–120
Sunchoke May 19 Sep 8 – Oct 13 110–150
Sweet Corn May 19 Jul 21 – Sep 1 60–90
Tatsoi Mar 24 Apr 28 May 5 Jul 14 Jun 9 – Jul 14 35–50
Tomatillo Mar 3 May 19 May 26 Jul 28 – Oct 6 60–85
Tomatoes Mar 3 May 19 May 26 Jul 28 – Oct 6 60–85
Turnip Apr 28 Jul 14 Jun 9 – Jul 14 40–60
Watercress Mar 24 Apr 28 May 5 Jul 14 Jun 16 – Jul 21 40–60
Watermelon Mar 24 May 19 May 26 Aug 4 – Sep 22 70–100
Wax Beans May 19 Jul 14 – Sep 8 50–65
Zucchini Mar 24 May 19 May 26 Jul 14 – Sep 8 45–60

🍓 Fruits to Grow in Portage County

22 fruits that grow well in Zone 4b with planting dates for Portage County.

Show all 22 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Alpine Strawberries Jun 2 Sep 1 – Oct 27 90–180
Aronia Jun 2 730–1095
Blueberries Jun 2 730–1095
Cantaloupe Jun 2 Aug 11 – Sep 15 70–90
Cranberries Jun 2 730–1095
Currants Jun 2 730–1095
Elderberries Jun 2 730–1095
Goji Berries Jun 2 730–1095
Gooseberries Jun 2 730–1095
Grapes Jun 2 730–1095
Ground Cherry Jun 2 Aug 11 – Oct 6 65–80
Hardy Kiwi Jun 2 1095–1825
Haskaps Jun 2 730–1095
Honeydew Jun 2 Aug 25 – Oct 6 80–110
Jostaberry Jun 2 730–1095
Lingonberries Jun 2 730–1095
Medlar Jun 2 1095–1825
Mulberries Jun 2 730–1825
Persimmon Jun 2 1095–2555
Raspberries Jun 2 365–730
Serviceberries Jun 2 730–1095
Strawberries Jun 2 Sep 1 – Oct 27 90–365

🌿 Herbs to Grow in Portage County

30 herbs that grow well in Zone 4b with planting dates for Portage County.

Show all 30 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Angelica Mar 24 Apr 28 Apr 28 Jul 14 365–730
Anise Mar 24 Apr 28 Apr 28 Jul 14 Jul 28 – Sep 22 90–120
Basil Mar 10 May 12 May 26 Jul 21 – Sep 22 50–75
Bee Balm May 12 Aug 11 – Oct 6 90–120
Borage Mar 24 Apr 28 Apr 28 Jul 14 Jun 23 – Aug 11 50–60
Caraway Mar 24 Apr 28 Apr 28 Jul 14 365–450
Catnip May 12 Jul 14 – Sep 15 60–80
Chamomile Mar 24 Apr 28 Apr 28 Jul 14 Jun 30 – Sep 8 60–90
Chervil Mar 24 Apr 28 Apr 28 Jul 14 Jun 9 – Aug 11 40–60
Chives May 12 Jul 14 – Sep 22 60–90
Cilantro Mar 24 Apr 28 Apr 28 Jul 14 Jun 9 – Aug 11 40–60
Comfrey May 12 Jul 14 – Sep 22 60–90
Dill Mar 24 Apr 28 Apr 28 Jul 14 Jun 9 – Aug 11 40–60
Fennel (herb) Mar 24 Apr 28 Apr 28 Jul 14 Jun 30 – Sep 8 60–90
Garlic Chives May 12 Jul 14 – Sep 22 60–90
Horehound May 12 Jul 28 – Sep 22 75–90
Hyssop May 12 Jul 21 – Sep 22 70–90
Lemon Balm May 12 Jul 14 – Sep 1 60–70
Lovage May 12 Jul 21 – Sep 22 70–90
Mint May 12 Jul 14 – Sep 22 60–90
Oregano May 12 Jul 14 – Sep 22 60–90
Parsley Mar 24 Apr 28 Apr 28 Jul 14 Jun 30 – Sep 1 60–80
Rue May 12 Jul 21 – Sep 22 70–90
Sage May 12 Jul 28 – Sep 22 75–90
Savory May 12 Jul 7 – Sep 1 50–70
Sorrel Mar 24 Apr 28 Apr 28 Jul 14 Jun 9 – Aug 11 40–60
Tarragon May 12 Jul 14 – Sep 22 60–90
Thai Basil Mar 10 May 12 May 26 Jul 21 – Sep 22 50–75
Thyme May 12 Jul 21 – Sep 22 70–90
Valerian May 12 Sep 15 – Oct 6 120–180

🌸 Flowers to Grow in Portage County

49 flowers that grow well in Zone 4b with planting dates for Portage County.

Show all 49 flowers with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Bloom Days to Maturity
Ageratum Mar 17 May 12 May 12 Jul 7 – Sep 22 60–75
Alliums Aug 25 Sep 29 – Oct 27 28–42
Astilbe Feb 24 May 19 Aug 11 – Oct 6 70–100
Bachelor's Button Mar 17 Apr 21 May 5 Jul 7 – Sep 8 60–90
Begonias Feb 17 May 12 Jul 21 – Sep 29 70–90
Black-eyed Susan Feb 24 May 5 May 19 Aug 11 – Oct 27 60–80
Bleeding Hearts Feb 24 May 19 Jul 14 – Aug 25 60–90
Calendula Mar 17 Apr 21 May 5 Jun 23 – Sep 8 50–70
Celosia Mar 31 May 19 May 19 Jul 21 – Oct 6 60–90
Columbine Feb 24 May 19 May 19 Jul 14 – Sep 1 70–100
Coreopsis Feb 24 May 12 May 19 Aug 4 – Oct 27 60–80
Cosmos Apr 7 May 12 May 12 Jul 21 – Oct 13 60–90
Crocus Aug 25 Jun 30 – Jul 28 10–20
Daffodils Aug 25 Jul 7 – Aug 4 20–40
Dahlias Apr 7 May 19 May 19 Aug 18 – Oct 27 70–120
Daylily Feb 24 May 19 Aug 18 – Oct 27 60–90
Dianthus Mar 3 Apr 14 Apr 28 Jun 16 – Aug 25 60–80
Echinacea (Purple Coneflower) Feb 24 May 19 May 19 Aug 18 – Oct 27 70–90
Foxglove Feb 24 May 19 May 19 Jul 14 – Aug 25 80–120
Gaillardia (Blanket Flower) Mar 10 May 19 May 19 Jul 28 – Nov 3 70–100
Geraniums Feb 17 May 12 Jul 21 – Sep 29 70–100
Gladiolus May 12 May 12 Aug 11 – Oct 20 70–100
Hostas Feb 17 May 19 Aug 18 – Oct 27 60–90
Hyacinths Aug 25 Jul 28 – Aug 18 14–28
Hydrangeas Feb 17 May 19 Aug 11 – Oct 13 90–150
Impatiens Mar 3 May 19 Aug 4 – Oct 6 60–75
Irises Division May 19 Jul 14 – Aug 18 60–100
Larkspur Apr 7 Jun 16 – Aug 4 60–90
Lilies Division May 19 Aug 11 – Oct 13 70–120
Lobelia Feb 24 May 5 Jun 30 – Sep 1 70–80
Lupine Feb 24 May 19 May 19 Jul 14 – Aug 25 75–100
Marigolds Mar 24 May 12 May 12 Jul 7 – Sep 22 50–70
Nasturtium Apr 7 May 12 May 12 Jul 7 – Sep 29 55–65
Pansy Feb 17 May 5 Jun 30 – Aug 18 70–90
Peonies Division May 19 Jul 28 – Sep 1 90–120
Petunia Mar 3 May 12 Jul 21 – Oct 6 70–90
Phlox Feb 24 May 19 May 19 Aug 11 – Oct 20 80–110
Portulaca Mar 31 May 19 May 19 Jul 7 – Sep 22 50–70
Roses Feb 17 May 19 Aug 11 – Oct 27 90–180
Salvia Mar 3 May 12 Jul 21 – Sep 29 70–90
Sedum (Stonecrop) Feb 24 May 19 Sep 22 – Nov 17 60–90
Snapdragon Feb 24 May 5 Jul 14 – Sep 8 70–100
Sunflower Apr 14 May 12 May 12 Aug 4 – Oct 6 70–100
Sweet Alyssum Mar 17 Apr 28 May 5 Jun 16 – Aug 18 45–60
Sweet Pea Mar 24 Mar 31 May 5 Jul 28 – Sep 15 65–85
Tulips Aug 25 Jul 21 – Aug 11 15–30
Vinca (Annual) Feb 17 May 19 Jul 28 – Oct 6 70–90
Yarrow Feb 24 May 5 May 19 Aug 4 – Oct 27 60–90
Zinnia Apr 7 May 12 May 12 Jul 21 – Oct 6 60–70

Monthly Planting Guide for Portage County

Gardening Guides & Resources

Helpful guides from The Ultimate Homestead to improve your garden in Portage County.

Frequently Asked Questions

What planting zone is Portage County, WI?

Portage 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 Portage County, WI?

Based on 31 years of NOAA weather station data, the median last spring frost in Portage County falls around May 5. In 8 out of 10 years, last frost lands between April 22 and May 19 — a 27-day window of variability. Use May 19 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in Portage County, WI?

The median first fall frost in Portage County arrives around October 6. In cold years it can arrive as early as September 23; in mild years as late as October 19. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

How long is the growing season in Portage County?

Portage County has a frost-free growing season of approximately 154 days. This is enough time for most warm-season crops including tomatoes, peppers, and squash with proper timing.

What is the soil like in Portage County for gardening?

Portage County has predominantly Silt Loam soil with a pH range of 5.9–7.1 and Excessively Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.

What is grown commercially in Portage County?

Portage County has commercial agriculture that includes Soybeans, Corn, Hay, Dairy, Oats. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.

Is Portage County a good location for home gardening?

Portage County scores 73/100 (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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA GHCN-D daily station data (1994–2024) from 3 weather stations in or near Portage County (31 years of records). Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.