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Washington County, UT — Planting Guide

Washington County is in USDA Zone 8a. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 3,524 ft, Washington County receives approximately 12.7 in of rainfall annually. Summer highs average 90°F with winter lows around 38°F. The predominant soil type is Loam.

Based on 31 years of NOAA climate station data, the last frost date here varies by 88 days year to year — ranging from February 28 in warm years to May 27 in cold years. The growing season is trending shorter by about 8.38 days per decade. Washington County scores 29/100 (Challenging) on the Microclimate Index.

🌡️ Zone

8a (10°F to 15°F min)

❄️ Last Frost

April 6

🍂 First Frost

November 1

📅 Growing Season

209 days

⛰️ Elevation

3,524 ft

🌧️ Annual Rainfall

12.7 in

Washington County, UT Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1

Monthly Watering Calendar

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

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 1" +3.7" Feb 0.6" +3.2" Mar 1.1" +3.1" Apr 1.2" +2.9" May 1.4" +3.4" Jun 0.9" +3.1" Jul 1.2" +2.9" Aug 1.4" +3.4" Sep 0.9" +3.1" Oct 1.2" +3.3" Nov 1" Dec 0.8"
Rainfall sufficient Supplemental water needed Heavy watering required - - - 1"/week garden need
View detailed monthly data
MonthAvg RainfallRainy DaysExtra Water NeededWatering Effort
Jan 1 in 6 days None
Feb 0.6 in 5 days 3.7 in Critical
Mar 1.1 in 7 days 3.2 in Critical
Apr 1.2 in 7 days 3.1 in Critical
May 1.4 in 8 days 2.9 in High
Jun 0.9 in 5 days 3.4 in Critical
Jul 1.2 in 5 days 3.1 in Critical
Aug 1.4 in 6 days 2.9 in High
Sep 0.9 in 6 days 3.4 in Critical
Oct 1.2 in 5 days 3.1 in Critical
Nov 1 in 6 days 3.3 in Critical
Dec 0.8 in 7 days None

Annual total: 12.7 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.

Washington County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

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 Apr 6 → Nov 1 209 frost-free days Protect crops frost returns Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Safe: May 27 Protect by: Nov 21

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 27 Nov 21 178 days
Cautious Apr 24 Nov 10 200 days
Average year Apr 6 Nov 1 209 days
Optimistic Mar 13 Oct 16 217 days
Aggressive (risky) Feb 28 Sep 30 214 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±88 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.

⚠️
Is the growing season changing?

Yes — growing seasons are getting shorter here (about 8.4 days per decade). Use the "Conservative" dates and choose fast-maturing varieties.

Gardening Difficulty Score

29 Challenging
Frost Timing Risk
10.0/10
Drought Risk
9.5/10
Soil Difficulty
1.0/10
Altitude Challenge
5.1/10
Climate Shift
10.0/10
Rainfall Challenge
6.9/10

Washington County has challenging growing conditions. Season extension and careful variety selection are essential.

Zone 8a Frost Countdown
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Loading...
Last Frost: Apr 6 First Frost: Nov 1

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

County Extension Office

Washington County Utah State University Extension Extension Office

Phone: 435-797-2200

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 UT →

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 Washington County

Soil testing Arid gardening Pest identification
Finding local nurseries & garden centers in Washington County

Why Buy Local

Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Washington 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 Washington County UT" or "garden center Washington 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 Washington County UT" or check your extension office and local parks department. Facebook groups like "Washington County Gardeners" or "Utah 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 Squash (Winter) (harvest ends Sep 7) 55 days until frost
After Green Beans (harvest ends Jul 27) 97 days until frost
After Melon (harvest ends Aug 17) 76 days until frost
After Peppers (harvest ends Aug 31) 62 days until frost
After Lettuce (harvest ends Jul 20) 104 days until frost
After Squash (Summer) (harvest ends Aug 10) 83 days until frost

Sunlight & Day Length

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

Longest Day

14.6 hours

Summer solstice daylight

Shortest Day

9.4 hours

Winter solstice daylight

Peak Sun Hours

10.5 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.

14hr 12hr 4h 7h 10h 13h 16h 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 9.7 hr 5.5 hr Short day
February 10.6 hr 6.1 hr Short day
March 11.7 hr 6.7 hr Short day
April 13 hr 7.4 hr Neutral
May 14 hr 8.7 hr Long day
June 14.6 hr 10.5 hr Long day
July 14.3 hr 9.6 hr Long day
August 13.4 hr 9 hr Neutral
September 12.2 hr 8.4 hr Neutral
October 11 hr 7.3 hr Short day
November 10 hr 5.8 hr Short day
December 9.4 hr 5.3 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 May through Oct.

Best Month to Compost

Jun

Microbial activity peaks when soil is warm.

Active Composting

8 months

Nearly year-round composting.

60°F 70°F 20° 40° 60° 80° 100° 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 37°F 43°F ❄️ Dormant ~36 weeks
Feb 35°F 42°F ❄️ Dormant ~36 weeks
Mar 44°F 46°F 🐢 Slow ~24 weeks
Apr 51°F 53°F ♻️ Active ~14 weeks
May 62°F 62°F ♻️ Active ~14 weeks
Jun 73°F 70°F 🔥 Peak ~8 weeks
Jul 82°F 75°F 🔥 Peak ~8 weeks
Aug 83°F 77°F 🔥 Peak ~8 weeks
Sep 74°F 76°F 🔥 Peak ~8 weeks
Oct 65°F 67°F 🔥 Peak ~8 weeks
Nov 53°F 58°F ♻️ Active ~14 weeks
Dec 42°F 48°F 🐢 Slow ~24 weeks

Highlighted rows = soil 60°F+ (safe for warm-season transplants). Compost finishes fastest during peak activity months.

Pest & Disease Pressure in Washington County

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

Insect Pest Pressure

7.3 / 10

High — expect multiple pest generations. Preventative measures essential.

Disease Risk

1.9 / 10

Low disease risk — dry conditions reduce fungal problems.

Seasonal Risk

Spring High
Summer High
Fall High
Winter Low
View 6 common pests in your area
PestRisk LevelPeak Months
Aphids High Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov
Squash vine borers Moderate May, Jun, Jul
Stink bugs High Apr, May, Jun, Jul, Aug, Sep, Oct
Whiteflies Moderate May, Jun, Jul, Aug, Sep, Oct
Spider mites Moderate Jun, Jul, Aug, Sep
Fire ants Low Mar, Apr, May, Jun, Jul, Aug, Sep, Oct
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 Washington County

Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.

Fall Cover Crops (7 options) — Plant after harvest to protect soil over winter
Crop Plant By Terminate N-Fixing Soil Benefit
Austrian winter peas Sep 1 Mar 16 ✓ Yes Fixes nitrogen, good for heavy clay soils
Crimson clover Sep 2 Mar 23 ✓ Yes Fixes nitrogen, attracts pollinators in spring
Daikon radish Sep 16 Mar 16 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Aug 24 Mar 16 ✓ Yes Excellent nitrogen fixer, good for depleted soils
Oats Oct 6 Mar 23 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jul 30 Mar 16 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Aug 8 Mar 16 Erosion control, weed suppression, good biomass
Spring Cover Crops (4 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat Apr 11 Sep 6 Rapid growth, attracts pollinators, suppresses weeds
Cowpeas (southern peas) Apr 14 Sep 6 ✓ Yes Excellent nitrogen fixer for warm climates, edible
Sorghum-sudan grass Apr 11 Aug 23 Massive biomass, breaks compaction, suppresses nematodes
White clover Mar 12 Aug 23 ✓ 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 Apr 18 Oct 18 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: 16 mph   Summer: 11 mph

Fall: 11 mph   Winter: 15 mph

Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.

Windbreak Benefit

7.1/10

Strongly recommended — a windbreak (fence, hedge, or row of tall crops like corn or sunflowers) will significantly improve garden yields.

Frost Pocket Risk

High

Hilly terrain with 1,742 ft of elevation range — cold air pools in low spots. Avoid planting frost-sensitive crops in valleys.

Rainwater Harvesting Potential

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

Annual Collection

6,329 gal

Per 1,000 sq ft of roof area (at 80% collection efficiency)

Recommended Setup

8 rain barrels (55 gal each)

For a typical 500 sq ft garden. Serious collectors: consider a 2,000 gal tank.

Legal Status

Limited

Your state has quantity limits on rainwater collection — check local regulations before installing large systems.

Best Collection Months

Apr, May, Jul, Aug

Highest rainfall months — your barrels will fill up quickly during these months.

Months to Draw From Storage

Feb, Jun, Sep, 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 12.7 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 6,329 gallons annually
  • Check UT state regulations — rainwater harvesting has quantity limits
  • In your dry climate, every drop counts — consider a larger cistern system
  • Position collection tanks in shade to reduce evaporation and algae growth

Soil & Growing Conditions in Washington County

Soil Type

Loam

Soil pH 6.7–8 · Excessively Drained drainage

Good candidate for raised beds to maximise drainage and extend the season.

Watering Needs

Drought stress: 9.5/10

Very high drought stress. Irrigation is critical for garden success. Focus on water-efficient techniques and drought-adapted crops.

Season Tips

209-day frost-free season

Plenty of time for warm-season crops. Start heat-lovers indoors 6–8 weeks before last frost to maximise your harvest window.

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.

Get My Free Planner →

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 Washington County

115 vegetables that grow well in Zone 8a with planting dates for Washington County.

Show all 115 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Acorn Squash Mar 9 Apr 13 Apr 20 Jul 13 – Aug 17 80–100
Amaranth Feb 16 Apr 13 Apr 20 Jul 20 – Sep 7 90–120
Artichoke Apr 20 Aug 24 – Nov 2 120–180
Arugula Mar 2 Mar 23 Apr 6 May 11 – Jul 13 30–50
Asparagus Apr 20 730–1095
Beets Mar 23 May 18 – Jun 15 50–70
Belgian Endive Mar 2 Mar 23 Apr 6 Jul 27 – Sep 21 110–150
Bitter Melon Feb 16 Apr 13 Apr 20 Jun 22 – Aug 3 60–90
Black Beans Apr 13 Jul 13 – Aug 31 90–120
Bok Choy Mar 2 Mar 23 Apr 6 May 18 – Jun 22 40–60
Broccoli Mar 2 Mar 23 Apr 6 Jun 8 – Jul 20 60–90
Broccoli Rabe Mar 2 Mar 23 Apr 6 May 18 – Jun 22 40–60
Brussels Sprouts Mar 2 Mar 23 Apr 6 Jul 6 – Aug 31 90–130
Butternut Squash Mar 9 Apr 13 Apr 20 Jul 20 – Aug 24 85–110
Cabbage Mar 2 Mar 23 Apr 6 Jun 8 – Aug 3 60–100
Calabash Feb 16 Apr 13 Apr 20 Jul 13 – Sep 7 80–120
Cardoon Apr 20 Aug 24 – Oct 5 120–150
Carrots Mar 23 May 25 – Jun 29 60–80
Cauliflower Mar 2 Mar 23 Apr 6 Jun 1 – Aug 3 55–100
Celeriac Mar 2 Mar 23 Apr 6 Jul 20 – Aug 24 100–120
Celery Mar 2 Mar 23 Apr 6 Jun 29 – Aug 24 80–120
Celtuce Mar 2 Mar 23 Apr 6 Jun 8 – Jul 20 60–90
Chard Mar 2 Mar 23 Apr 6 Jun 1 – Jul 20 50–60
Chayote Feb 16 Apr 13 Apr 20 Aug 24 – Nov 2 120–180
Chickpeas Mar 2 Mar 23 Apr 6 Jun 29 – Aug 10 80–110
Chicory Mar 2 Mar 23 Apr 6 Jun 8 – Jul 20 60–85
Chinese Cabbage Mar 2 Mar 23 Apr 6 Jun 1 – Jun 29 50–70
Christmas Lima Beans Feb 16 Apr 13 Apr 20 Jul 13 – Aug 17 80–100
Collard Greens Mar 2 Mar 23 Apr 6 Jun 1 – Aug 3 55–75
Corn Apr 13 Jun 15 – Aug 10 60–100
Cowpeas Apr 13 Jun 15 – Jul 27 60–90
Cress Mar 2 Mar 23 Apr 6 Apr 20 – May 11 14–21
Crookneck Squash Mar 9 Apr 13 Apr 20 Jun 8 – Jul 6 45–60
Crosne Mar 23 Aug 24 – Oct 26 150–200
Cucumber Mar 9 Apr 13 Apr 20 Jun 15 – Aug 10 50–70
Daikon Mar 23 May 18 – Jun 15 50–70
Delicata Squash Mar 9 Apr 13 Apr 20 Jul 13 – Aug 17 80–100
Edamame Apr 13 Jun 29 – Aug 10 75–100
Eggplant Feb 2 Apr 13 Apr 20 Jun 29 – Aug 31 65–85
Endive Mar 2 Mar 23 Apr 6 May 25 – Jun 29 45–65
Escarole Mar 2 Mar 23 Apr 6 Jun 1 – Jun 29 50–70
Fava Beans Mar 2 Mar 23 Apr 6 Jun 22 – Aug 3 75–100
Fennel Feb 16 Apr 13 Apr 20 Jun 22 – Aug 3 60–90
Garlic 90–240
Ginger Feb 16 Apr 13 Apr 20 Dec 21 – Jan 4 240–300
Green Beans Apr 13 Jun 8 – Aug 3 50–65
Horseradish Apr 20 Aug 24 – Nov 2 120–180
Hot Peppers Feb 2 Apr 13 Apr 20 Jun 29 – Oct 5 70–120
Hubbard Squash Mar 9 Apr 13 Apr 20 Aug 3 – Sep 7 100–120
Jicama Feb 16 Apr 13 Apr 20 Aug 24 – Nov 2 120–180
Kabocha Mar 9 Apr 13 Apr 20 Jul 20 – Aug 17 85–100
Kai Lan Mar 2 Mar 23 Apr 6 May 25 – Jun 22 45–60
Kale Mar 2 Mar 23 Apr 6 Jun 1 – Jul 27 50–70
Kidney Beans Apr 13 Jul 13 – Aug 17 85–110
Kohlrabi Mar 2 Mar 23 Apr 6 May 25 – Jun 29 45–65
Komatsuna Mar 2 Mar 23 Apr 6 May 11 – Jun 15 35–50
Leeks Mar 2 Mar 23 Apr 6 Jul 6 – Sep 21 90–150
Lentils Mar 2 Mar 23 Apr 6 Jun 29 – Aug 10 80–110
Lettuce Mar 2 Mar 23 Apr 6 May 11 – Jul 20 30–60
Lima Beans Apr 13 Jun 15 – Jul 27 60–90
Loofah Feb 16 Apr 13 Apr 20 Aug 3 – Oct 5 100–150
Luffa Feb 16 Apr 13 Apr 20 Jul 20 – Oct 5 90–150
Mache Mar 2 Mar 23 Apr 6 May 18 – Jun 22 40–60
Malabar Spinach Feb 16 Apr 13 Apr 20 Jun 15 – Jul 13 55–70
Melon Mar 9 Apr 13 Apr 20 Jun 29 – Aug 17 70–100
Microgreens Mar 2 Mar 23 Apr 6 Apr 13 – May 11 7–21
Mitsuba Mar 2 Mar 23 Mar 30 May 25 – Jul 20 50–70
Mizuna Mar 2 Mar 23 Apr 6 May 11 – Jun 8 30–45
Mustard Greens Mar 2 Mar 23 Apr 6 May 11 – Jul 13 30–50
Napa Cabbage Mar 2 Mar 23 Apr 6 Jun 1 – Jul 6 55–75
New Zealand Spinach Feb 16 Apr 13 Apr 20 Jun 15 – Jul 13 55–70
Okra Feb 16 Apr 13 Apr 20 Jun 15 – Aug 10 50–65
Onion Mar 2 Mar 23 Apr 6 Jul 6 – Aug 24 90–120
Pac Choi Mar 2 Mar 23 Apr 6 May 18 – Jun 15 40–55
Parsnip Mar 23 Jul 6 – Aug 17 100–130
Patty Pan Squash Mar 9 Apr 13 Apr 20 Jun 8 – Jul 6 45–60
Peas Mar 2 Mar 23 Apr 6 Jun 1 – Jul 27 55–70
Peppers Feb 2 Apr 13 Apr 20 Jun 22 – Aug 31 60–90
Pole Beans Feb 16 Apr 13 Apr 20 Jun 15 – Aug 10 55–70
Potatoes Feb 16 Apr 13 Apr 20 Jun 29 – Sep 7 70–120
Pumpkin Mar 9 Apr 13 Apr 20 Jul 20 – Sep 7 85–120
Purslane Mar 2 Mar 23 Apr 6 May 18 – Jun 22 40–60
Radicchio Mar 2 Mar 23 Apr 6 Jun 8 – Jul 13 60–80
Radish Mar 23 Apr 20 – May 11 22–35
Rhubarb Apr 27 365–730
Romanesco Mar 2 Mar 23 Apr 6 Jun 22 – Aug 3 75–100
Rutabaga Mar 23 Jun 15 – Jul 20 80–100
Salsify Mar 23 Jul 6 – Aug 17 100–130
Savoy Cabbage Mar 2 Mar 23 Apr 6 Jun 15 – Aug 10 70–110
Scallions Mar 2 Mar 23 Apr 6 Jun 1 – Jun 29 50–70
Scarlet Runner Beans Feb 16 Apr 13 Apr 20 Jun 22 – Jul 27 60–80
Shallot Mar 2 Mar 23 Apr 6 Jul 6 – Aug 24 90–120
Shiso Feb 16 Apr 13 Apr 20 Jun 15 – Aug 10 50–70
Snap Peas Feb 16 Apr 13 Apr 20 Jun 15 – Aug 10 55–70
Snow Peas Mar 2 Mar 23 Apr 6 Jun 1 – Jul 27 50–65
Soybeans Apr 13 Jul 6 – Aug 31 80–120
Spaghetti Squash Mar 9 Apr 13 Apr 20 Jul 20 – Aug 17 85–100
Spinach Mar 2 Mar 23 Apr 6 May 11 – Jul 13 35–50
Squash (Summer) Mar 9 Apr 13 Apr 20 Jun 8 – Aug 10 45–65
Squash (Winter) Mar 9 Apr 13 Apr 20 Jul 13 – Sep 7 80–120
Sunchoke Apr 20 Aug 10 – Oct 5 110–150
Sunflower Feb 16 Apr 13 Apr 20 Jun 29 – Aug 17 70–100
Sweet Corn Apr 13 Jun 15 – Jul 27 60–90
Sweet Potatoes Feb 16 Apr 13 Apr 20 Jul 20 – Sep 7 90–120
Tatsoi Mar 2 Mar 23 Apr 6 May 11 – Jun 15 35–50
Tomatillo Feb 16 Apr 13 Apr 20 Jun 22 – Aug 31 60–85
Tomatoes Feb 16 Apr 13 Apr 20 Jun 22 – Aug 31 60–85
Turmeric Feb 16 Apr 13 Apr 20 Dec 21 – Jan 4 240–300
Turnip Mar 23 May 4 – Jun 8 40–60
Watercress Mar 2 Mar 23 Apr 6 May 18 – Jun 22 40–60
Watermelon Mar 9 Apr 13 Apr 20 Jun 29 – Aug 17 70–100
Wax Beans Apr 13 Jun 8 – Aug 3 50–65
Winter Melon Feb 16 Apr 13 Apr 20 Jul 20 – Sep 7 90–120
Yard Long Beans Feb 16 Apr 13 Apr 20 Jun 15 – Jul 27 55–80
Zucchini Mar 9 Apr 13 Apr 20 Jun 8 – Aug 3 45–60

🍓 Fruits to Grow in Washington County

27 fruits that grow well in Zone 8a with planting dates for Washington County.

Show all 27 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Alpine Strawberries Apr 27 Jul 27 – Nov 9 90–180
Aronia Apr 27 730–1095
Blackberries Apr 27 365–730
Blueberries Apr 27 730–1095
Boysenberries Apr 27 365–730
Cantaloupe Apr 27 Jul 6 – Aug 10 70–90
Che Fruit Apr 27 1095–1825
Elderberries Apr 27 730–1095
Figs Apr 27 730–1825
Goji Berries Apr 27 730–1095
Gooseberries Apr 27 730–1095
Grapes Apr 27 730–1095
Ground Cherry Apr 27 Jul 6 – Aug 31 65–80
Hardy Kiwi Apr 27 1095–1825
Honeydew Apr 27 Jul 20 – Aug 31 80–110
Jostaberry Apr 27 730–1095
Kiwi Apr 27 1095–1825
Loquat Apr 27 730–1825
Medlar Apr 27 1095–1825
Mulberries Apr 27 730–1825
Pawpaw Apr 27 1095–2555
Persimmon Apr 27 1095–2555
Pomegranate Apr 27 730–1095
Quince Apr 27 1095–1825
Raspberries Apr 27 365–730
Serviceberries Apr 27 730–1095
Strawberries Apr 27 Jul 27 – Jan 11 90–365

🌿 Herbs to Grow in Washington County

42 herbs that grow well in Zone 8a with planting dates for Washington County.

Show all 42 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Angelica Mar 2 Mar 23 Mar 30 365–730
Anise Mar 2 Mar 23 Mar 30 Jun 29 – Sep 14 90–120
Basil Feb 16 Apr 13 Apr 20 Jun 15 – Aug 17 50–75
Bee Balm Apr 13 Jul 13 – Sep 28 90–120
Borage Mar 2 Mar 23 Mar 30 May 25 – Jul 13 50–60
Caraway Mar 2 Mar 23 Mar 30 365–450
Catnip Apr 13 Jun 15 – Aug 17 60–80
Chamomile Mar 2 Mar 23 Mar 30 Jun 1 – Aug 10 60–90
Chervil Mar 2 Mar 23 Mar 30 May 11 – Jul 13 40–60
Chives Apr 13 Jun 15 – Aug 24 60–90
Cilantro Mar 2 Mar 23 Mar 30 May 11 – Jul 13 40–60
Comfrey Apr 13 Jun 15 – Aug 24 60–90
Cumin Mar 2 Mar 23 Mar 30 Jul 13 – Sep 14 100–120
Dill Mar 2 Mar 23 Mar 30 May 11 – Jul 13 40–60
Echinacea Apr 13 Aug 17 – Nov 23 120–180
Epazote Feb 16 Apr 13 Apr 20 Jun 8 – Aug 3 45–60
Fennel (herb) Mar 2 Mar 23 Mar 30 Jun 1 – Aug 10 60–90
Feverfew Apr 13 Jul 13 – Sep 28 90–120
Garlic Chives Apr 13 Jun 15 – Aug 24 60–90
Horehound Apr 13 Jun 29 – Aug 24 75–90
Hyssop Apr 13 Jun 22 – Aug 24 70–90
Lavender Apr 13 Jul 13 – Dec 14 90–200
Lemon Balm Apr 13 Jun 15 – Aug 3 60–70
Lemon Thyme Apr 13 Jun 22 – Aug 24 70–90
Lemon Verbena Feb 16 Apr 13 Apr 20 Jun 22 – Aug 31 60–90
Lemongrass Feb 16 Apr 13 Apr 20 Jul 6 – Oct 5 75–120
Lovage Apr 13 Jun 22 – Aug 24 70–90
Marjoram Apr 13 Jun 15 – Aug 24 60–90
Mint Apr 13 Jun 15 – Aug 24 60–90
Oregano Apr 13 Jun 15 – Aug 24 60–90
Parsley Mar 2 Mar 23 Mar 30 Jun 1 – Aug 3 60–80
Rosemary Apr 13 Jul 6 – Nov 23 80–180
Rue Apr 13 Jun 22 – Aug 24 70–90
Sage Apr 13 Jun 29 – Aug 24 75–90
Savory Apr 13 Jun 8 – Aug 3 50–70
Sorrel Mar 2 Mar 23 Mar 30 May 11 – Jul 13 40–60
Stevia Feb 16 Apr 13 Apr 20 Jun 22 – Aug 31 60–90
Tarragon Apr 13 Jun 15 – Aug 24 60–90
Thai Basil Feb 16 Apr 13 Apr 20 Jun 15 – Aug 17 50–75
Thyme Apr 13 Jun 22 – Aug 24 70–90
Valerian Apr 13 Aug 17 – Nov 23 120–180
Yarrow Apr 13 Jul 13 – Sep 28 90–120

Monthly Planting Guide for Washington County

Gardening Guides & Resources

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

Frequently Asked Questions

What planting zone is Washington County, UT?

Washington County is in USDA Hardiness Zone 8a. 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 Washington County, UT?

Based on 31 years of NOAA weather station data, the median last spring frost in Washington County falls around April 6. In 8 out of 10 years, last frost lands between February 28 and May 27 — a 88-day window of variability. Use May 27 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in Washington County, UT?

The median first fall frost in Washington County arrives around November 1. In cold years it can arrive as early as September 30; in mild years as late as November 21. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

How long is the growing season in Washington County?

Washington County has a frost-free growing season of approximately 209 days. This long season supports multiple succession plantings and warm-season crops that need extended heat, like sweet potatoes and melons. Climate records show the growing season is trending shorter by about 8.38 days per decade.

What is the soil like in Washington County for gardening?

Washington County has predominantly Loam soil with a pH range of 6.7–8 and Excessively Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.

What is grown commercially in Washington County?

Washington County has commercial agriculture that includes Hay, Cattle, Wheat, Barley. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.

Is Washington County a good location for home gardening?

Washington County scores 29/100 (Challenging) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. Gardening here benefits from close attention to frost timing and season extension due to the challenging microclimate factors.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — designed to help Washington County gardeners in Zone 8a 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.

Level Up Your Garden

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