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Delta County, CO — Planting Guide

Delta County, Colorado Zone 6b June

June in Delta County, Colorado — your action list

June is a pivotal month for Delta County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 1
Avg. first frost October 8
Soil temp (4") 60°F
Watering Critical
Pest pressure High
Daylight 14.7 hrs
  1. Start basil, cucumber, and kale under lights

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Pick carrots, kale, and lettuce

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Coming up in July — start thinking about
  • Starting indoors: peppers, astilbe, and begonias
  • First harvests: basil, carrots, and cucumber
  • Fall sowing: carrots, kale, and lettuce

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Delta County is in USDA Zone 6b. The average last spring frost is May 1 and the first fall frost is October 8, giving you a growing season of approximately 160 days.

At an elevation of 4,470 ft, Delta County receives approximately 13.4 in of rainfall annually. Summer highs average 87°F with winter lows around 27°F. The predominant soil type is Loam.

Based on 31 years of NOAA climate station data, the last frost date here varies by 30 days year to year — ranging from April 17 in warm years to May 17 in cold years. The growing season is trending longer by about 4.66 days per decade. Delta County scores 33/100 (Challenging) on the Microclimate Index.

🌡️ Zone

6b (-5°F to 0°F min)

❄️ Last Frost

May 1

🍂 First Frost

October 8

📅 Growing Season

160 days

⛰️ Elevation

4,470 ft

🌧️ Annual Rainfall

13.4 in

Delta County, CO Moderate season
160 days
Last Spring Frost May 1
160 growing days
First Fall Frost October 8

Monthly Watering Calendar for Delta County

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

Why this matters: Most vegetables want about 1 inch of water per week. Delta County gets 13" a year — months that hit that 1"/week need zero supplemental watering; months that fall short, the table tells you how much to add. Saves you from drowning roots and from drought-stressing plants into bolting.

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 1" Feb 0.7" +3.1" Mar 1.2" +2.9" Apr 1.4" +2.9" May 1.4" +3.4" Jun 0.9" +3" Jul 1.3" +2.9" Aug 1.4" +3.2" Sep 1.1" +3.2" Oct 1.1" Nov 1.1" 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 0.7 in 5 days None
Mar 1.2 in 7 days 3.1 in Critical
Apr 1.4 in 8 days 2.9 in High
May 1.4 in 8 days 2.9 in High
Jun 0.9 in 5 days 3.4 in Critical
Jul 1.3 in 6 days 3 in High
Aug 1.4 in 6 days 2.9 in High
Sep 1.1 in 6 days 3.2 in Critical
Oct 1.1 in 6 days 3.2 in Critical
Nov 1.1 in 5 days None
Dec 0.8 in 8 days None

Annual total: 13.4 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.

Delta County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

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 May 1 → Oct 8 160 frost-free days Protect crops frost returns Apr May Jun Jul Aug Sep Oct Nov Safe: May 17 Protect by: Oct 25

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 17 Oct 25 161 days
Cautious May 8 Oct 13 158 days
Average year May 1 Oct 8 160 days
Optimistic Apr 22 Oct 4 165 days
Aggressive (risky) Apr 17 Sep 23 159 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±30 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 longer here (about 4.7 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.

Gardening Difficulty Score

33 Challenging
Frost Timing Risk
10.0/10
Drought Risk
5.5/10
Soil Difficulty
1.0/10
Altitude Challenge
6.9/10
Climate Shift
10.0/10
Rainfall Challenge
6.6/10

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

Zone 6b Frost Countdown
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Loading...
Last Frost: May 1 First Frost: Oct 8

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

County Extension Office

Delta County Colorado State University Extension Extension Office

Phone: 970-491-6281

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 CO →

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 Delta County

Soil testing High-altitude gardening Water conservation Pest diagnostics
Finding local nurseries & garden centers in Delta County

Why Buy Local

Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Delta 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 Delta County CO" or "garden center Delta 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 Delta County CO" or check your extension office and local parks department. Facebook groups like "Delta County Gardeners" or "Colorado 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 Cauliflower (harvest ends Aug 28) 41 days until frost
After Kale (harvest ends Aug 21) 48 days until frost
After Peas (harvest ends Aug 21) 48 days until frost
After Corn (harvest ends Aug 28) 41 days until frost
After Cantaloupe (harvest ends Sep 4) 34 days until frost
After Sweet Corn (harvest ends Aug 14) 55 days until frost

Sunlight & Day Length in Delta County

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

For new gardeners: Lettuce and cilantro "bolt" (go to seed) when days lengthen. Knowing your day-length curve helps you time spring plantings to harvest before the bolting trigger hits. Delta County's daylight ranges shape the planting calendar.

Longest Day

14.7 hours

Summer solstice daylight

Shortest Day

9.3 hours

Winter solstice daylight

Peak Sun Hours

10.4 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 9.6 hr 5.4 hr Short day
February 10.5 hr 5.9 hr Short day
March 11.7 hr 6.7 hr Short day
April 13 hr 7.3 hr Neutral
May 14.1 hr 8.7 hr Long day
June 14.7 hr 10.4 hr Long day
July 14.5 hr 10 hr Long day
August 13.5 hr 9.4 hr Neutral
September 12.2 hr 8.2 hr Neutral
October 11 hr 7.4 hr Short day
November 9.8 hr 5.5 hr Short day
December 9.3 hr 5.1 hr Short day

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

Soil Temperature & Composting in Delta County

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

What this means for you: Soil temperature predicts plant emergence better than calendar dates. Delta 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

Jul

Microbial activity peaks when soil is warm.

Active Composting

5 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 20°F 26°F ❄️ Dormant ~36 weeks
Feb 18°F 25°F ❄️ Dormant ~36 weeks
Mar 27°F 30°F ❄️ Dormant ~36 weeks
Apr 39°F 40°F ❄️ Dormant ~36 weeks
May 50°F 49°F 🐢 Slow ~24 weeks
Jun 60°F 57°F ♻️ Active ~14 weeks
Jul 71°F 64°F 🔥 Peak ~8 weeks
Aug 70°F 66°F 🔥 Peak ~8 weeks
Sep 63°F 64°F ♻️ Active ~14 weeks
Oct 50°F 54°F ♻️ Active ~14 weeks
Nov 39°F 42°F ❄️ Dormant ~36 weeks
Dec 26°F 35°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 Delta County

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

What this means for you: Pollinators are the good bugs. Pest pressure is the bad bugs. Delta County's climate makes both more abundant in warm humid regions, and rarer in cold dry ones — plan habitat to encourage the good while managing the bad.

Insect Pest Pressure

6 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

1.7 / 10

Low disease risk — dry conditions reduce fungal problems.

Seasonal Risk

Spring Low
Summer High
Fall Low
Winter Low
View 6 common pests in your area
PestRisk LevelPeak Months
Aphids Moderate Apr, May, Jun, Jul, Aug, Sep
Japanese beetles Moderate Jun, Jul, Aug
Squash vine borers Moderate Jun, Jul
Tomato hornworms Moderate Jun, Jul, Aug
Cucumber beetles Low May, Jun, Jul
Stink bugs Moderate Jun, Jul, Aug, Sep
Organic pest management tips
  • Maintain healthy soil with regular compost additions to build natural pest resistance
  • Practice crop rotation annually to break pest cycles
  • Encourage beneficial insects with flowering herbs like dill, fennel, and yarrow

Cover Crops for Delta County

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

Quick context: Bare soil is wasted soil — it loses nutrients to rain, dries out, compacts, and gets taken over by weeds. Cover crops (clovers, ryegrass, vetch, peas) are the "between seasons" trick that makes soil better every year. In Delta County, you can fit a cover crop into the gaps.

Spring Cover Crops (3 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat May 10 Aug 6 Rapid growth, attracts pollinators, suppresses weeds
Sorghum-sudan grass May 5 Aug 13 Massive biomass, breaks compaction, suppresses nematodes
White clover Apr 6 Aug 6 ✓ 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 Jun 1 Sep 10 Deep roots break compaction, attract pollinators and beneficial insects
Fall Cover Crops (7 options) — Plant after harvest to protect soil over winter
Crop Plant By Terminate N-Fixing Soil Benefit
Austrian winter peas Aug 9 Apr 17 ✓ Yes Fixes nitrogen, good for heavy clay soils
Crimson clover Aug 16 Apr 17 ✓ Yes Fixes nitrogen, attracts pollinators in spring
Daikon radish Aug 25 Apr 10 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Jul 22 Apr 10 ✓ Yes Excellent nitrogen fixer, good for depleted soils
Oats Aug 28 Apr 10 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jul 17 Apr 17 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jul 12 Apr 10 Erosion control, weed suppression, good biomass

Wind & Microclimate in Delta County

The practical takeaway: Light wind is good (strengthens stems, aids pollination); strong wind is bad (snaps stems, dries leaves, scatters seeds). Delta County averages 10.4 mph. If you garden near coast, ridge, or open plains, you're likely above that — plan for it.

Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.

Seasonal Wind Speed

Spring: 16 mph   Summer: 10 mph

Fall: 11 mph   Winter: 14 mph

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

Windbreak Benefit

7/10

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 1,417 ft of elevation range — cold air pools in low spots. Avoid planting frost-sensitive crops in valleys.

Rainwater Harvesting in Delta County

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

Why this matters: A single rain barrel under a downspout catches 50 gallons in a 0.5" storm. Delta County's 13" annual rainfall means even modest harvesting systems quickly amortize their cost in water savings.

Annual Collection

6,678 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, 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 13.4 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 6,678 gallons annually
  • Check CO 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 Delta County

Soil Type

Loam

Soil pH 6.7–7.8 · Well Drained drainage

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

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

160-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 Delta County

107 vegetables that grow well in Zone 6b with planting dates for Delta County.

Show all 107 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Acorn Squash Mar 27 May 8 May 15 Aug 7 – Sep 11 80–100
Amaranth Mar 6 May 8 May 15 Aug 14 – Oct 2 90–120
Arugula Mar 27 Apr 17 May 1 Jul 30 Jun 5 – Aug 7 30–50
Asparagus May 15 730–1095
Beets Apr 17 Jul 30 Jun 12 – Jul 10 50–70
Belgian Endive Mar 27 Apr 17 May 1 Jul 30 Aug 21 – Oct 16 110–150
Bitter Melon Mar 6 May 8 May 15 Jul 17 – Aug 28 60–90
Black Beans May 8 Aug 7 – Sep 25 90–120
Bok Choy Mar 27 Apr 17 May 1 Jul 30 Jun 12 – Jul 17 40–60
Broccoli Mar 27 Apr 17 May 1 Jul 30 Jul 3 – Aug 14 60–90
Broccoli Rabe Mar 27 Apr 17 May 1 Jul 30 Jun 12 – Jul 17 40–60
Brussels Sprouts Mar 27 Apr 17 May 1 Jul 30 Jul 31 – Sep 25 90–130
Butternut Squash Mar 27 May 8 May 15 Aug 14 – Sep 18 85–110
Cabbage Mar 27 Apr 17 May 1 Jul 30 Jul 3 – Aug 28 60–100
Calabash Mar 6 May 8 May 15 Aug 7 – Oct 2 80–120
Carrots Apr 17 Jul 30 Jun 19 – Jul 24 60–80
Cauliflower Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Aug 28 55–100
Celeriac Mar 27 Apr 17 May 1 Jul 30 Aug 14 – Sep 18 100–120
Celery Mar 27 Apr 17 May 1 Jul 30 Jul 24 – Sep 18 80–120
Celtuce Mar 27 Apr 17 May 1 Jul 30 Jul 3 – Aug 14 60–90
Chard Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Aug 14 50–60
Chickpeas Mar 27 Apr 17 May 1 Jul 30 Jul 24 – Sep 4 80–110
Chicory Mar 27 Apr 17 May 1 Jul 30 Jul 3 – Aug 14 60–85
Chinese Cabbage Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Jul 24 50–70
Christmas Lima Beans Mar 6 May 8 May 15 Aug 7 – Sep 11 80–100
Collard Greens Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Aug 28 55–75
Corn May 8 Jul 10 – Sep 4 60–100
Cowpeas May 8 Jul 10 – Aug 21 60–90
Cress Mar 27 Apr 17 May 1 Jul 30 May 15 – Jun 5 14–21
Crookneck Squash Mar 27 May 8 May 15 Jul 3 – Jul 31 45–60
Crosne Apr 17 Jul 30 Sep 18 – Oct 30 150–200
Cucumber Mar 27 May 8 May 15 Jul 10 – Sep 4 50–70
Daikon Apr 17 Jul 30 Jun 12 – Jul 10 50–70
Delicata Squash Mar 27 May 8 May 15 Aug 7 – Sep 11 80–100
Edamame May 8 Jul 24 – Sep 4 75–100
Eggplant Feb 20 May 8 May 15 Jul 24 – Sep 25 65–85
Endive Mar 27 Apr 17 May 1 Jul 30 Jun 19 – Jul 24 45–65
Escarole Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Jul 24 50–70
Fava Beans Mar 27 Apr 17 May 1 Jul 30 Jul 17 – Aug 28 75–100
Fennel Mar 6 May 8 May 15 Jul 17 – Aug 28 60–90
Garlic Aug 27 Nov 26 – Mar 11 90–240
Green Beans May 8 Jul 3 – Aug 28 50–65
Horseradish May 15 Sep 18 – Nov 27 120–180
Hot Peppers Feb 20 May 8 May 15 Jul 24 – Oct 30 70–120
Hubbard Squash Mar 27 May 8 May 15 Aug 28 – Oct 2 100–120
Kabocha Mar 27 May 8 May 15 Aug 14 – Sep 11 85–100
Kai Lan Mar 27 Apr 17 May 1 Jul 30 Jun 19 – Jul 17 45–60
Kale Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Aug 21 50–70
Kidney Beans May 8 Aug 7 – Sep 11 85–110
Kohlrabi Mar 27 Apr 17 May 1 Jul 30 Jun 19 – Jul 24 45–65
Komatsuna Mar 27 Apr 17 May 1 Jul 30 Jun 5 – Jul 10 35–50
Leeks Mar 27 Apr 17 May 1 Jul 30 Jul 31 – Oct 16 90–150
Lentils Mar 27 Apr 17 May 1 Jul 30 Jul 24 – Sep 4 80–110
Lettuce Mar 27 Apr 17 May 1 Jul 30 Jun 5 – Aug 14 30–60
Lima Beans May 8 Jul 10 – Aug 21 60–90
Loofah Mar 6 May 8 May 15 Aug 28 – Oct 30 100–150
Luffa Mar 6 May 8 May 15 Aug 14 – Oct 30 90–150
Mache Mar 27 Apr 17 May 1 Jul 30 Jun 12 – Jul 17 40–60
Melon Mar 27 May 8 May 15 Jul 24 – Sep 11 70–100
Microgreens Mar 27 Apr 17 May 1 Jul 30 May 8 – Jun 5 7–21
Mitsuba Mar 27 Apr 17 Apr 24 Jul 30 Jun 19 – Aug 14 50–70
Mizuna Mar 27 Apr 17 May 1 Jul 30 Jun 5 – Jul 3 30–45
Mustard Greens Mar 27 Apr 17 May 1 Jul 30 Jun 5 – Aug 7 30–50
Napa Cabbage Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Jul 31 55–75
New Zealand Spinach Mar 6 May 8 May 15 Jul 10 – Aug 7 55–70
Okra Mar 6 May 8 May 15 Jul 10 – Sep 4 50–65
Onion Mar 27 Apr 17 May 1 Jul 30 Jul 31 – Sep 18 90–120
Pac Choi Mar 27 Apr 17 May 1 Jul 30 Jun 12 – Jul 10 40–55
Parsnip Apr 17 Jul 30 Jul 31 – Sep 11 100–130
Patty Pan Squash Mar 27 May 8 May 15 Jul 3 – Jul 31 45–60
Peas Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Aug 21 55–70
Peppers Feb 20 May 8 May 15 Jul 17 – Sep 25 60–90
Pole Beans Mar 6 May 8 May 15 Jul 10 – Sep 4 55–70
Potatoes Mar 6 May 8 May 15 Jul 24 – Oct 2 70–120
Pumpkin Mar 27 May 8 May 15 Aug 14 – Oct 2 85–120
Purslane Mar 27 Apr 17 May 1 Jul 30 Jun 12 – Jul 17 40–60
Radicchio Mar 27 Apr 17 May 1 Jul 30 Jul 3 – Aug 7 60–80
Radish Apr 17 Jul 30 May 15 – Jun 5 22–35
Rhubarb May 22 365–730
Romanesco Mar 27 Apr 17 May 1 Jul 30 Jul 17 – Aug 28 75–100
Rutabaga Apr 17 Jul 30 Jul 10 – Aug 14 80–100
Salsify Apr 17 Jul 30 Jul 31 – Sep 11 100–130
Savoy Cabbage Mar 27 Apr 17 May 1 Jul 30 Jul 10 – Sep 4 70–110
Scallions Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Jul 24 50–70
Scarlet Runner Beans Mar 6 May 8 May 15 Jul 17 – Aug 21 60–80
Shallot Mar 27 Apr 17 May 1 Jul 30 Jul 31 – Sep 18 90–120
Shiso Mar 13 May 8 May 15 Jul 10 – Sep 4 50–70
Snap Peas Mar 6 May 8 May 15 Jul 10 – Sep 4 55–70
Snow Peas Mar 27 Apr 17 May 1 Jul 30 Jun 26 – Aug 21 50–65
Soybeans May 8 Jul 31 – Sep 25 80–120
Spaghetti Squash Mar 27 May 8 May 15 Aug 14 – Sep 11 85–100
Spinach Mar 27 Apr 17 May 1 Jul 30 Jun 5 – Aug 7 35–50
Squash (Summer) Mar 27 May 8 May 15 Jul 3 – Sep 4 45–65
Squash (Winter) Mar 27 May 8 May 15 Aug 7 – Oct 2 80–120
Sunchoke May 15 Sep 4 – Oct 30 110–150
Sweet Corn May 8 Jul 10 – Aug 21 60–90
Sweet Potatoes Mar 6 May 8 May 15 Aug 14 – Oct 2 90–120
Tatsoi Mar 27 Apr 17 May 1 Jul 30 Jun 5 – Jul 10 35–50
Tomatillo Mar 6 May 8 May 15 Jul 17 – Sep 25 60–85
Tomatoes Mar 6 May 8 May 15 Jul 17 – Sep 25 60–85
Turnip Apr 17 Jul 30 May 29 – Jul 3 40–60
Watercress Mar 27 Apr 17 May 1 Jul 30 Jun 12 – Jul 17 40–60
Watermelon Mar 27 May 8 May 15 Jul 24 – Sep 11 70–100
Wax Beans May 8 Jul 3 – Aug 28 50–65
Winter Melon Mar 6 May 8 May 15 Aug 14 – Oct 2 90–120
Yard Long Beans Mar 6 May 8 May 15 Jul 10 – Aug 21 55–80
Zucchini Mar 27 May 8 May 15 Jul 3 – Aug 28 45–60

🍓 Fruits to Grow in Delta County

27 fruits that grow well in Zone 6b with planting dates for Delta County.

Show all 27 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Alpine Strawberries May 22 Aug 21 – Dec 4 90–180
Aronia May 22 730–1095
Blackberries May 22 365–730
Blueberries May 22 730–1095
Boysenberries May 22 365–730
Cantaloupe May 22 Jul 31 – Sep 4 70–90
Che Fruit May 22 1095–1825
Cranberries May 22 730–1095
Currants May 22 730–1095
Elderberries May 22 730–1095
Goji Berries May 22 730–1095
Gooseberries May 22 730–1095
Grapes May 22 730–1095
Ground Cherry May 22 Jul 31 – Sep 25 65–80
Hardy Kiwi May 22 1095–1825
Haskaps May 22 730–1095
Honeydew May 22 Aug 14 – Sep 25 80–110
Jostaberry May 22 730–1095
Lingonberries May 22 730–1095
Medlar May 22 1095–1825
Mulberries May 22 730–1825
Pawpaw May 22 1095–2555
Persimmon May 22 1095–2555
Quince May 22 1095–1825
Raspberries May 22 365–730
Serviceberries May 22 730–1095
Strawberries May 22 Aug 21 – Dec 4 90–365

🌿 Herbs to Grow in Delta County

35 herbs that grow well in Zone 6b with planting dates for Delta County.

Show all 35 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Angelica Mar 27 Apr 17 Apr 24 Jul 30 365–730
Anise Mar 27 Apr 17 Apr 24 Jul 30 Jul 24 – Oct 9 90–120
Basil Mar 13 May 8 May 15 Jul 10 – Sep 11 50–75
Bee Balm May 8 Aug 7 – Oct 23 90–120
Borage Mar 27 Apr 17 Apr 24 Jul 30 Jun 19 – Aug 7 50–60
Caraway Mar 27 Apr 17 Apr 24 Jul 30 365–450
Catnip May 8 Jul 10 – Sep 11 60–80
Chamomile Mar 27 Apr 17 Apr 24 Jul 30 Jun 26 – Sep 4 60–90
Chervil Mar 27 Apr 17 Apr 24 Jul 30 Jun 5 – Aug 7 40–60
Chives May 8 Jul 10 – Sep 18 60–90
Cilantro Mar 27 Apr 17 Apr 24 Jul 30 Jun 5 – Aug 7 40–60
Comfrey May 8 Jul 10 – Sep 18 60–90
Cumin Mar 27 Apr 17 Apr 24 Jul 30 Aug 7 – Oct 9 100–120
Dill Mar 27 Apr 17 Apr 24 Jul 30 Jun 5 – Aug 7 40–60
Epazote Mar 13 May 8 May 15 Jul 3 – Aug 28 45–60
Fennel (herb) Mar 27 Apr 17 Apr 24 Jul 30 Jun 26 – Sep 4 60–90
Feverfew May 8 Aug 7 – Oct 23 90–120
Garlic Chives May 8 Jul 10 – Sep 18 60–90
Horehound May 8 Jul 24 – Sep 18 75–90
Hyssop May 8 Jul 17 – Sep 18 70–90
Lemon Balm May 8 Jul 10 – Aug 28 60–70
Lemon Thyme May 8 Jul 17 – Sep 18 70–90
Lovage May 8 Jul 17 – Sep 18 70–90
Marjoram May 8 Jul 10 – Sep 18 60–90
Mint May 8 Jul 10 – Sep 18 60–90
Oregano May 8 Jul 10 – Sep 18 60–90
Parsley Mar 27 Apr 17 Apr 24 Jul 30 Jun 26 – Aug 28 60–80
Rue May 8 Jul 17 – Sep 18 70–90
Sage May 8 Jul 24 – Sep 18 75–90
Savory May 8 Jul 3 – Aug 28 50–70
Sorrel Mar 27 Apr 17 Apr 24 Jul 30 Jun 5 – Aug 7 40–60
Tarragon May 8 Jul 10 – Sep 18 60–90
Thai Basil Mar 13 May 8 May 15 Jul 10 – Sep 11 50–75
Thyme May 8 Jul 17 – Sep 18 70–90
Valerian May 8 Sep 11 – Nov 20 120–180

🌸 Flowers to Grow in Delta County

53 flowers that grow well in Zone 6b with planting dates for Delta County.

Show all 53 flowers with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Bloom Days to Maturity
Ageratum Mar 13 May 1 May 1 Jun 26 – Oct 9 60–75
Alliums Aug 27 Sep 24 – Oct 22 28–42
Anemones Apr 3 May 1 May 29 – Jun 26 90–120
Astilbe Feb 27 May 8 Jul 17 – Sep 25 70–100
Bachelor's Button Mar 20 Apr 3 May 1 Aug 27 Jul 3 – Sep 25 60–90
Begonias Feb 20 May 8 Jul 17 – Oct 23 70–90
Black-eyed Susan Feb 27 May 1 May 8 Jul 24 – Nov 13 60–80
Bleeding Hearts Feb 27 May 8 Jul 3 – Aug 7 60–90
Calendula Mar 20 Apr 3 May 1 Jun 19 – Sep 25 50–70
California Poppy Apr 3 Jun 12 – Aug 7 60–90
Celosia Mar 27 May 8 May 8 Jul 10 – Oct 30 60–90
Columbine Feb 27 May 8 May 8 Jul 3 – Aug 7 70–100
Coreopsis Feb 27 May 1 May 8 Jul 17 – Nov 13 60–80
Cosmos Apr 3 May 1 May 1 Jul 10 – Oct 23 60–90
Crocus Aug 27 Jul 16 – Aug 6 10–20
Daffodils Aug 27 Jul 23 – Aug 13 20–40
Dahlias Apr 3 May 8 May 8 Jul 24 – Nov 13 70–120
Daylily Feb 27 May 8 Jul 24 – Nov 13 60–90
Dianthus Mar 6 Apr 3 Apr 10 May 29 – Aug 28 60–80
Echinacea (Purple Coneflower) Feb 27 May 8 May 8 Jul 24 – Nov 13 70–90
Foxglove Feb 27 May 8 May 8 Jul 3 – Aug 7 80–120
Gaillardia (Blanket Flower) Mar 13 May 8 May 8 Jul 17 – Nov 20 70–100
Geraniums Feb 20 May 8 Jul 17 – Oct 23 70–100
Gladiolus May 1 May 1 Jul 17 – Nov 6 70–100
Hostas Feb 20 May 8 Jul 24 – Nov 13 60–90
Hyacinths Aug 27 Aug 13 – Sep 3 14–28
Hydrangeas Feb 20 May 8 Jul 17 – Oct 30 90–150
Impatiens Mar 6 May 8 Jul 17 – Oct 30 60–75
Irises Division May 8 Jul 3 – Jul 31 60–100
Larkspur Apr 3 Jun 12 – Aug 7 60–90
Lavender Feb 20 May 15 Jul 24 – Sep 18 90–120
Lilies Division May 8 Jul 17 – Oct 23 70–120
Lobelia Feb 27 Apr 17 Jun 12 – Sep 4 70–80
Lupine Feb 27 May 8 May 8 Jul 3 – Aug 7 75–100
Marigolds Mar 20 May 1 May 1 Jun 26 – Oct 2 50–70
Nasturtium Apr 3 May 1 May 1 Jun 26 – Oct 23 55–65
Pansy Feb 20 May 1 Aug 13 Jun 26 – Sep 4 70–90
Peonies Division May 8 Jul 10 – Aug 14 90–120
Petunia Mar 6 May 8 Jul 17 – Oct 30 70–90
Phlox Feb 27 May 8 May 8 Jul 17 – Oct 9 80–110
Portulaca Mar 27 May 8 May 8 Jun 26 – Oct 16 50–70
Ranunculus Mar 20 May 1 Jun 5 – Jul 3 90–120
Roses Feb 20 May 8 Jul 17 – Nov 13 90–180
Salvia Feb 27 May 1 Jul 10 – Oct 23 70–90
Sedum (Stonecrop) Feb 27 May 8 Aug 28 – Nov 20 60–90
Snapdragon Feb 20 Apr 10 May 1 Jul 10 – Sep 25 70–100
Sunflower Apr 10 May 1 May 1 Jul 24 – Oct 23 70–100
Sweet Alyssum Mar 20 Apr 10 May 1 Jun 12 – Aug 28 45–60
Sweet Pea Mar 20 Mar 27 May 1 Jul 17 – Sep 25 65–85
Tulips Sep 3 Aug 13 – Sep 10 15–30
Vinca (Annual) Feb 20 May 8 Jul 17 – Oct 30 70–90
Yarrow Feb 27 May 1 May 8 Jul 17 – Nov 13 60–90
Zinnia Apr 3 May 1 May 1 Jul 10 – Oct 16 60–70

Monthly Planting Guide for Delta County

Gardening Guides & Resources

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

Frequently Asked Questions

What planting zone is Delta County, CO?

Delta County is in USDA Hardiness Zone 6b. 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 Delta County, CO?

Based on 31 years of NOAA weather station data, the median last spring frost in Delta County falls around May 1. In 8 out of 10 years, last frost lands between April 17 and May 17 — a 30-day window of variability. Use May 17 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in Delta County, CO?

The median first fall frost in Delta County arrives around October 8. In cold years it can arrive as early as September 23; in mild years as late as October 25. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

How long is the growing season in Delta County?

Delta County has a frost-free growing season of approximately 160 days. This is enough time for most warm-season crops including tomatoes, peppers, and squash with proper timing. Climate records show the growing season is trending longer by about 4.66 days per decade.

What is the soil like in Delta County for gardening?

Delta County has predominantly Loam soil with a pH range of 6.7–7.8 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.

What is grown commercially in Delta County?

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

Is Delta County a good location for home gardening?

Delta County scores 33/100 (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.

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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 Delta County (31 years of records). Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. Last updated: June 2026.

Sources & credits

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