Adams County, CO — Planting Guide
May in Adams County, Colorado — your action list
Each item below is timed to Adams County, Colorado's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Move basil, cucumber, and kale from tray to bed
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
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Scatter basil, cucumber, and green beans into prepared beds
Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.
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Bring in the radish, cress, and microgreens
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Get ahead of June
- Starting indoors: basil, cucumber, and kale
- First harvests: carrots, kale, and lettuce
Adams County is in USDA Zone 6a. The average last spring frost is May 4 and the first fall frost is October 5, giving you a growing season of approximately 154 days.
At an elevation of 5,827 ft, Adams County receives approximately 23.9 in of rainfall annually. Summer highs average 87°F with winter lows around 18°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 29 days year to year — ranging from April 22 in warm years to May 21 in cold years. The growing season is trending longer by about 5.33 days per decade. Adams County scores 32/100 (Challenging) on the Microclimate Index.
🌡️ Zone
6a (°F to °F min)
❄️ Last Frost
May 4
🍂 First Frost
October 5
📅 Growing Season
154 days
⛰️ Elevation
5,827 ft
🌧️ Annual Rainfall
23.9 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 | 1.8 in | 6 days | — | None |
| Feb | 1.2 in | 6 days | — | None |
| Mar | 2.2 in | 7 days | — | None |
| Apr | 2.4 in | 6 days | 1.9 in | High |
| May | 2.5 in | 8 days | 1.8 in | High |
| Jun | 1.6 in | 4 days | 2.7 in | High |
| Jul | 2.1 in | 6 days | 2.2 in | High |
| Aug | 2.8 in | 7 days | 1.5 in | Moderate |
| Sep | 1.8 in | 6 days | 2.5 in | High |
| Oct | 2.3 in | 6 days | 2 in | High |
| Nov | 1.5 in | 6 days | — | None |
| Dec | 1.6 in | 6 days | — | None |
Annual total: 23.8 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.
Adams County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.7
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 17 | 149 days |
| Cautious | May 13 | Oct 9 | 149 days |
| Average year | May 4 | Oct 5 | 154 days |
| Optimistic | Apr 29 | Sep 27 | 151 days |
| Aggressive (risky) | Apr 22 | Sep 13 | 144 days |
Not very — frost dates can vary by ±29 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.
Yes — growing seasons are getting longer here (about 5.3 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Adams County has challenging growing conditions. Season extension and careful variety selection are essential.
Local Gardening Help in Adams 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 Adams County's climate and soil.
County Extension Office
Adams 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.
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 Adams County
Finding local nurseries & garden centers in Adams County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Adams 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 Adams County CO" or "garden center Adams 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 Adams County CO" or check your extension office and local parks department. Facebook groups like "Adams 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
Sunlight & Day Length
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
Longest Day
14.8 hours
Summer solstice daylight
Shortest Day
9.2 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.
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 | 9.5 hr | 5.3 hr | Short day |
| February | 10.5 hr | 5.9 hr | Short day |
| March | 11.7 hr | 6.7 hr | Short day |
| April | 13.1 hr | 7.8 hr | Neutral |
| May | 14.2 hr | 8.9 hr | Long day |
| June | 14.8 hr | 10.4 hr | Long day |
| July | 14.6 hr | 9.9 hr | Long day |
| August | 13.6 hr | 8.8 hr | Neutral |
| September | 12.2 hr | 8.2 hr | Neutral |
| October | 10.9 hr | 7.4 hr | Short day |
| November | 9.8 hr | 5.6 hr | Short day |
| December | 9.2 hr | 5 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 Jul through Aug.
Best Month to Compost
Jun
Microbial activity peaks when soil is warm.
Active Composting
4 months
Short season — insulate pile or use indoor vermicomposting.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 7°F | 14°F | ❄️ Dormant | ~36 weeks |
| Feb | 5°F | 14°F | ❄️ Dormant | ~36 weeks |
| Mar | 16°F | 18°F | ❄️ Dormant | ~36 weeks |
| Apr | 28°F | 26°F | ❄️ Dormant | ~36 weeks |
| May | 40°F | 39°F | 🐢 Slow | ~24 weeks |
| Jun | 52°F | 47°F | ♻️ Active | ~14 weeks |
| Jul | 60°F | 56°F | ♻️ Active | ~14 weeks |
| Aug | 63°F | 57°F | ♻️ Active | ~14 weeks |
| Sep | 53°F | 53°F | ♻️ Active | ~14 weeks |
| Oct | 42°F | 45°F | 🐢 Slow | ~24 weeks |
| Nov | 24°F | 33°F | ❄️ Dormant | ~36 weeks |
| Dec | 15°F | 20°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 Adams 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
Low disease risk — dry conditions reduce fungal problems.
Seasonal Risk
View 5 common pests in your area
| Pest | Risk Level | Peak Months |
|---|---|---|
| Aphids | Moderate | May, Jun, Jul, Aug |
| Japanese beetles | Moderate | Jun, Jul, Aug |
| Squash bugs | Moderate | Jun, Jul, Aug |
| Tomato hornworms | Low | Jul, Aug |
| Cabbage loopers | Low | May, Jun, Jul, Aug |
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 Adams County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Spring Cover Crops (3 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | May 11 | Aug 3 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Sorghum-sudan grass | May 17 | Aug 10 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Apr 7 | Jul 27 | ✓ 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 4 | Sep 14 | — | Deep roots break compaction, attract pollinators and beneficial insects |
Fall Cover Crops (6 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Austrian winter peas | Aug 13 | Apr 13 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Daikon radish | Aug 14 | Apr 20 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jul 29 | Apr 13 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Aug 29 | Apr 20 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jul 1 | Apr 20 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jul 16 | Apr 13 | — | Erosion control, weed suppression, good biomass |
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: 10 mph
Fall: 11 mph Winter: 16 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 1,396 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
11,861 gal
Per 1,000 sq ft of roof area (at 80% collection efficiency)
Recommended Setup
7 rain barrels (55 gal each)
For a typical 500 sq ft garden. Serious collectors: consider a 1,750 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, Aug, Oct
Highest rainfall months — your barrels will fill up quickly during these months.
Months to Draw From Storage
Feb, Nov, 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 23.8 inches of rain per year
- A 1,000 sq ft roof can collect roughly 11,861 gallons annually
- Check CO state regulations — rainwater harvesting has quantity limits
- Stock up on stored water before your dry season (Feb, Nov, Dec)
- Use a first-flush diverter to keep roof debris out of your collection
Soil & Growing Conditions in Adams County
Soil Type
Loam
Soil pH 6.6–7.7 · Well Drained drainage
Good candidate for raised beds to maximise drainage and extend the season.
Watering Needs
Drought stress: 7.5/10
High drought stress. Consistent irrigation is essential — consider drip systems, heavy mulch, and drought-tolerant varieties.
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 24-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.
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 Adams County
108 vegetables that grow well in Zone 6a with planting dates for Adams County.
Show all 108 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Mar 30 | May 11 | May 18 | Aug 10 – Sep 14 | 80–100 |
| Amaranth | Mar 9 | May 11 | May 18 | Aug 17 – Oct 5 | 90–120 |
| Arugula | Mar 30 | Apr 20 | May 4 | Jun 8 – Aug 10 | 30–50 |
| Asparagus | — | — | May 18 | — | 730–1095 |
| Beets | — | Apr 20 | — | Jun 15 – Jul 13 | 50–70 |
| Belgian Endive | Mar 30 | Apr 20 | May 4 | Aug 24 – Oct 19 | 110–150 |
| Bitter Melon | Mar 9 | May 11 | May 18 | Jul 20 – Aug 31 | 60–90 |
| Black Beans | — | May 11 | — | Aug 10 – Sep 28 | 90–120 |
| Bok Choy | Mar 30 | Apr 20 | May 4 | Jun 15 – Jul 20 | 40–60 |
| Broccoli | Mar 30 | Apr 20 | May 4 | Jul 6 – Aug 17 | 60–90 |
| Broccoli Rabe | Mar 30 | Apr 20 | May 4 | Jun 15 – Jul 20 | 40–60 |
| Brussels Sprouts | Mar 30 | Apr 20 | May 4 | Aug 3 – Sep 28 | 90–130 |
| Butternut Squash | Mar 30 | May 11 | May 18 | Aug 17 – Sep 21 | 85–110 |
| Cabbage | Mar 30 | Apr 20 | May 4 | Jul 6 – Aug 31 | 60–100 |
| Calabash | Mar 9 | May 11 | May 18 | Aug 10 – Oct 5 | 80–120 |
| Carrots | — | Apr 20 | — | Jun 22 – Jul 27 | 60–80 |
| Cauliflower | Mar 30 | Apr 20 | May 4 | Jun 29 – Aug 31 | 55–100 |
| Celeriac | Mar 30 | Apr 20 | May 4 | Aug 17 – Sep 21 | 100–120 |
| Celery | Mar 30 | Apr 20 | May 4 | Jul 27 – Sep 21 | 80–120 |
| Celtuce | Mar 30 | Apr 20 | May 4 | Jul 6 – Aug 17 | 60–90 |
| Chard | Mar 30 | Apr 20 | May 4 | Jun 29 – Aug 17 | 50–60 |
| Chickpeas | Mar 30 | Apr 20 | May 4 | Jul 27 – Sep 7 | 80–110 |
| Chicory | Mar 30 | Apr 20 | May 4 | Jul 6 – Aug 17 | 60–85 |
| Chinese Cabbage | Mar 30 | Apr 20 | May 4 | Jun 29 – Jul 27 | 50–70 |
| Christmas Lima Beans | Mar 9 | May 11 | May 18 | Aug 10 – Sep 14 | 80–100 |
| Collard Greens | Mar 30 | Apr 20 | May 4 | Jun 29 – Aug 31 | 55–75 |
| Corn | — | May 11 | — | Jul 13 – Sep 7 | 60–100 |
| Cowpeas | — | May 11 | — | Jul 13 – Aug 24 | 60–90 |
| Cress | Mar 30 | Apr 20 | May 4 | May 18 – Jun 8 | 14–21 |
| Crookneck Squash | Mar 30 | May 11 | May 18 | Jul 6 – Aug 3 | 45–60 |
| Crosne | — | Apr 20 | — | Sep 21 – Nov 2 | 150–200 |
| Cucumber | Mar 30 | May 11 | May 18 | Jul 13 – Sep 7 | 50–70 |
| Daikon | — | Apr 20 | — | Jun 15 – Jul 13 | 50–70 |
| Delicata Squash | Mar 30 | May 11 | May 18 | Aug 10 – Sep 14 | 80–100 |
| Edamame | — | May 11 | — | Jul 27 – Sep 7 | 75–100 |
| Eggplant | Feb 23 | May 11 | May 18 | Jul 27 – Sep 28 | 65–85 |
| Endive | Mar 30 | Apr 20 | May 4 | Jun 22 – Jul 27 | 45–65 |
| Escarole | Mar 30 | Apr 20 | May 4 | Jun 29 – Jul 27 | 50–70 |
| Fava Beans | Mar 30 | Apr 20 | May 4 | Jul 20 – Aug 31 | 75–100 |
| Fennel | Mar 9 | May 11 | May 18 | Jul 20 – Aug 31 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | May 11 | — | Jul 6 – Aug 31 | 50–65 |
| Horseradish | — | — | May 18 | Sep 21 – Nov 30 | 120–180 |
| Hot Peppers | Feb 23 | May 11 | May 18 | Jul 27 – Nov 2 | 70–120 |
| Hubbard Squash | Mar 30 | May 11 | May 18 | Aug 31 – Oct 5 | 100–120 |
| Kabocha | Mar 30 | May 11 | May 18 | Aug 17 – Sep 14 | 85–100 |
| Kai Lan | Mar 30 | Apr 20 | May 4 | Jun 22 – Jul 20 | 45–60 |
| Kale | Mar 30 | Apr 20 | May 4 | Jun 29 – Aug 24 | 50–70 |
| Kidney Beans | — | May 11 | — | Aug 10 – Sep 14 | 85–110 |
| Kohlrabi | Mar 30 | Apr 20 | May 4 | Jun 22 – Jul 27 | 45–65 |
| Komatsuna | Mar 30 | Apr 20 | May 4 | Jun 8 – Jul 13 | 35–50 |
| Leeks | Mar 30 | Apr 20 | May 4 | Aug 3 – Oct 19 | 90–150 |
| Lentils | Mar 30 | Apr 20 | May 4 | Jul 27 – Sep 7 | 80–110 |
| Lettuce | Mar 30 | Apr 20 | May 4 | Jun 8 – Aug 17 | 30–60 |
| Lima Beans | — | May 11 | — | Jul 13 – Aug 24 | 60–90 |
| Loofah | Mar 9 | May 11 | May 18 | Aug 31 – Nov 2 | 100–150 |
| Luffa | Mar 9 | May 11 | May 18 | Aug 17 – Nov 2 | 90–150 |
| Mache | Mar 30 | Apr 20 | May 4 | Jun 15 – Jul 20 | 40–60 |
| Melon | Mar 30 | May 11 | May 18 | Jul 27 – Sep 14 | 70–100 |
| Microgreens | Mar 30 | Apr 20 | May 4 | May 11 – Jun 8 | 7–21 |
| Mitsuba | Mar 30 | Apr 20 | Apr 27 | Jun 22 – Aug 17 | 50–70 |
| Mizuna | Mar 30 | Apr 20 | May 4 | Jun 8 – Jul 6 | 30–45 |
| Mustard Greens | Mar 30 | Apr 20 | May 4 | Jun 8 – Aug 10 | 30–50 |
| Napa Cabbage | Mar 30 | Apr 20 | May 4 | Jun 29 – Aug 3 | 55–75 |
| New Zealand Spinach | Mar 9 | May 11 | May 18 | Jul 13 – Aug 10 | 55–70 |
| Okra | Mar 9 | May 11 | May 18 | Jul 13 – Sep 7 | 50–65 |
| Onion | Mar 30 | Apr 20 | May 4 | Aug 3 – Sep 21 | 90–120 |
| Pac Choi | Mar 30 | Apr 20 | May 4 | Jun 15 – Jul 13 | 40–55 |
| Parsnip | — | Apr 20 | — | Aug 3 – Sep 14 | 100–130 |
| Patty Pan Squash | Mar 30 | May 11 | May 18 | Jul 6 – Aug 3 | 45–60 |
| Peas | Mar 30 | Apr 20 | May 4 | Jun 29 – Aug 24 | 55–70 |
| Peppers | Feb 23 | May 11 | May 18 | Jul 20 – Sep 28 | 60–90 |
| Pole Beans | Mar 9 | May 11 | May 18 | Jul 13 – Sep 7 | 55–70 |
| Potatoes | Mar 9 | May 11 | May 18 | Jul 27 – Oct 5 | 70–120 |
| Pumpkin | Mar 30 | May 11 | May 18 | Aug 17 – Oct 5 | 85–120 |
| Purslane | Mar 30 | Apr 20 | May 4 | Jun 15 – Jul 20 | 40–60 |
| Radicchio | Mar 30 | Apr 20 | May 4 | Jul 6 – Aug 10 | 60–80 |
| Radish | — | Apr 20 | — | May 18 – Jun 8 | 22–35 |
| Rhubarb | — | — | May 25 | — | 365–730 |
| Romanesco | Mar 30 | Apr 20 | May 4 | Jul 20 – Aug 31 | 75–100 |
| Rutabaga | — | Apr 20 | — | Jul 13 – Aug 17 | 80–100 |
| Salsify | — | Apr 20 | — | Aug 3 – Sep 14 | 100–130 |
| Savoy Cabbage | Mar 30 | Apr 20 | May 4 | Jul 13 – Sep 7 | 70–110 |
| Scallions | Mar 30 | Apr 20 | May 4 | Jun 29 – Jul 27 | 50–70 |
| Scarlet Runner Beans | Mar 9 | May 11 | May 18 | Jul 20 – Aug 24 | 60–80 |
| Shallot | Mar 30 | Apr 20 | May 4 | Aug 3 – Sep 21 | 90–120 |
| Shiso | Mar 16 | May 11 | May 18 | Jul 13 – Sep 7 | 50–70 |
| Snap Peas | Mar 9 | May 11 | May 18 | Jul 13 – Sep 7 | 55–70 |
| Snow Peas | Mar 30 | Apr 20 | May 4 | Jun 29 – Aug 24 | 50–65 |
| Soybeans | — | May 11 | — | Aug 3 – Sep 28 | 80–120 |
| Spaghetti Squash | Mar 30 | May 11 | May 18 | Aug 17 – Sep 14 | 85–100 |
| Spinach | Mar 30 | Apr 20 | May 4 | Jun 8 – Aug 10 | 35–50 |
| Squash (Summer) | Mar 30 | May 11 | May 18 | Jul 6 – Sep 7 | 45–65 |
| Squash (Winter) | Mar 30 | May 11 | May 18 | Aug 10 – Oct 5 | 80–120 |
| Sunchoke | — | — | May 18 | Sep 7 – Nov 2 | 110–150 |
| Sunflower | Mar 9 | May 11 | May 18 | Jul 27 – Sep 14 | 70–100 |
| Sweet Corn | — | May 11 | — | Jul 13 – Aug 24 | 60–90 |
| Sweet Potatoes | Mar 9 | May 11 | May 18 | Aug 17 – Oct 5 | 90–120 |
| Tatsoi | Mar 30 | Apr 20 | May 4 | Jun 8 – Jul 13 | 35–50 |
| Tomatillo | Mar 9 | May 11 | May 18 | Jul 20 – Sep 28 | 60–85 |
| Tomatoes | Mar 9 | May 11 | May 18 | Jul 20 – Sep 28 | 60–85 |
| Turnip | — | Apr 20 | — | Jun 1 – Jul 6 | 40–60 |
| Watercress | Mar 30 | Apr 20 | May 4 | Jun 15 – Jul 20 | 40–60 |
| Watermelon | Mar 30 | May 11 | May 18 | Jul 27 – Sep 14 | 70–100 |
| Wax Beans | — | May 11 | — | Jul 6 – Aug 31 | 50–65 |
| Winter Melon | Mar 9 | May 11 | May 18 | Aug 17 – Oct 5 | 90–120 |
| Yard Long Beans | Mar 9 | May 11 | May 18 | Jul 13 – Aug 24 | 55–80 |
| Zucchini | Mar 30 | May 11 | May 18 | Jul 6 – Aug 31 | 45–60 |
🍓 Fruits to Grow in Adams County
27 fruits that grow well in Zone 6a with planting dates for Adams County.
Show all 27 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | May 25 | Aug 24 – Dec 7 | 90–180 |
| Aronia | — | — | May 25 | — | 730–1095 |
| Blackberries | — | — | May 25 | — | 365–730 |
| Blueberries | — | — | May 25 | — | 730–1095 |
| Boysenberries | — | — | May 25 | — | 365–730 |
| Cantaloupe | — | — | May 25 | Aug 3 – Sep 7 | 70–90 |
| Che Fruit | — | — | May 25 | — | 1095–1825 |
| Cranberries | — | — | May 25 | — | 730–1095 |
| Currants | — | — | May 25 | — | 730–1095 |
| Elderberries | — | — | May 25 | — | 730–1095 |
| Goji Berries | — | — | May 25 | — | 730–1095 |
| Gooseberries | — | — | May 25 | — | 730–1095 |
| Grapes | — | — | May 25 | — | 730–1095 |
| Ground Cherry | — | — | May 25 | Aug 3 – Sep 28 | 65–80 |
| Hardy Kiwi | — | — | May 25 | — | 1095–1825 |
| Haskaps | — | — | May 25 | — | 730–1095 |
| Honeydew | — | — | May 25 | Aug 17 – Sep 28 | 80–110 |
| Jostaberry | — | — | May 25 | — | 730–1095 |
| Lingonberries | — | — | May 25 | — | 730–1095 |
| Medlar | — | — | May 25 | — | 1095–1825 |
| Mulberries | — | — | May 25 | — | 730–1825 |
| Pawpaw | — | — | May 25 | — | 1095–2555 |
| Persimmon | — | — | May 25 | — | 1095–2555 |
| Quince | — | — | May 25 | — | 1095–1825 |
| Raspberries | — | — | May 25 | — | 365–730 |
| Serviceberries | — | — | May 25 | — | 730–1095 |
| Strawberries | — | — | May 25 | Aug 24 – Dec 7 | 90–365 |
🌿 Herbs to Grow in Adams County
38 herbs that grow well in Zone 6a with planting dates for Adams County.
Show all 38 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Mar 30 | Apr 20 | Apr 27 | — | 365–730 |
| Anise | Mar 30 | Apr 20 | Apr 27 | Jul 27 – Oct 12 | 90–120 |
| Basil | Mar 16 | May 11 | May 18 | Jul 13 – Sep 14 | 50–75 |
| Bee Balm | — | — | May 11 | Aug 10 – Oct 26 | 90–120 |
| Borage | Mar 30 | Apr 20 | Apr 27 | Jun 22 – Aug 10 | 50–60 |
| Caraway | Mar 30 | Apr 20 | Apr 27 | — | 365–450 |
| Catnip | — | — | May 11 | Jul 13 – Sep 14 | 60–80 |
| Chamomile | Mar 30 | Apr 20 | Apr 27 | Jun 29 – Sep 7 | 60–90 |
| Chervil | Mar 30 | Apr 20 | Apr 27 | Jun 8 – Aug 10 | 40–60 |
| Chives | — | — | May 11 | Jul 13 – Sep 21 | 60–90 |
| Cilantro | Mar 30 | Apr 20 | Apr 27 | Jun 8 – Aug 10 | 40–60 |
| Comfrey | — | — | May 11 | Jul 13 – Sep 21 | 60–90 |
| Cumin | Mar 30 | Apr 20 | Apr 27 | Aug 10 – Oct 12 | 100–120 |
| Dill | Mar 30 | Apr 20 | Apr 27 | Jun 8 – Aug 10 | 40–60 |
| Echinacea | — | — | May 11 | Sep 14 – Nov 23 | 120–180 |
| Epazote | Mar 16 | May 11 | May 18 | Jul 6 – Aug 31 | 45–60 |
| Fennel (herb) | Mar 30 | Apr 20 | Apr 27 | Jun 29 – Sep 7 | 60–90 |
| Feverfew | — | — | May 11 | Aug 10 – Oct 26 | 90–120 |
| Garlic Chives | — | — | May 11 | Jul 13 – Sep 21 | 60–90 |
| Horehound | — | — | May 11 | Jul 27 – Sep 21 | 75–90 |
| Hyssop | — | — | May 11 | Jul 20 – Sep 21 | 70–90 |
| Lavender | — | — | May 11 | Aug 10 – Nov 23 | 90–200 |
| Lemon Balm | — | — | May 11 | Jul 13 – Aug 31 | 60–70 |
| Lemon Thyme | — | — | May 11 | Jul 20 – Sep 21 | 70–90 |
| Lovage | — | — | May 11 | Jul 20 – Sep 21 | 70–90 |
| Marjoram | — | — | May 11 | Jul 13 – Sep 21 | 60–90 |
| Mint | — | — | May 11 | Jul 13 – Sep 21 | 60–90 |
| Oregano | — | — | May 11 | Jul 13 – Sep 21 | 60–90 |
| Parsley | Mar 30 | Apr 20 | Apr 27 | Jun 29 – Aug 31 | 60–80 |
| Rue | — | — | May 11 | Jul 20 – Sep 21 | 70–90 |
| Sage | — | — | May 11 | Jul 27 – Sep 21 | 75–90 |
| Savory | — | — | May 11 | Jul 6 – Aug 31 | 50–70 |
| Sorrel | Mar 30 | Apr 20 | Apr 27 | Jun 8 – Aug 10 | 40–60 |
| Tarragon | — | — | May 11 | Jul 13 – Sep 21 | 60–90 |
| Thai Basil | Mar 16 | May 11 | May 18 | Jul 13 – Sep 14 | 50–75 |
| Thyme | — | — | May 11 | Jul 20 – Sep 21 | 70–90 |
| Valerian | — | — | May 11 | Sep 14 – Nov 23 | 120–180 |
| Yarrow | — | — | May 11 | Aug 10 – Oct 26 | 90–120 |
Monthly Planting Guide for Adams County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Adams County.
Frequently Asked Questions
What planting zone is Adams County, CO?
Adams County is in USDA Hardiness Zone 6a. 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 Adams County, CO?
Based on 31 years of NOAA weather station data, the median last spring frost in Adams County falls around May 4. In 8 out of 10 years, last frost lands between April 22 and May 21 — a 29-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 Adams County, CO?
The median first fall frost in Adams County arrives around October 5. In cold years it can arrive as early as September 13; in mild years as late as October 17. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Adams County?
Adams 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. Climate records show the growing season is trending longer by about 5.33 days per decade.
What is the soil like in Adams County for gardening?
Adams County has predominantly Loam soil with a pH range of 6.6–7.7 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Adams County?
Adams County has commercial agriculture that includes Cattle, Hay, Wheat, Sugar Beets, Barley. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Adams County a good location for home gardening?
Adams County scores 32/100 (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.
Your Adams County Garden Planner — Free
A 24-page printable planner built for Adams County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.
The Gardener's Encyclopedia to Companion Planting
The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.
- Proven pairings for 200+ vegetables, herbs, flowers, and fruits
- Full seed-starting + planting schedule with timing and spacing
- Bonus: square-foot gardening guide + printable seasonal planners
Seed Saving & Storage Guide
Most saved seeds go bad before next season. This shows exactly when to pick, how to dry, and where to store seeds from 200 plants so yours don't.
- 200 plants, step-by-step: life cycle, pollination type, isolation
- Exact temperature + humidity ranges that keep seeds viable
- Bonus: searchable Google Sheets tracker + custom GPT assistant
Composting Guide for Homesteaders
Turn kitchen scraps and yard waste into compost that actually feeds the garden — instead of a pile that smells, attracts pests, and never breaks down.
- 14 sections on composting methods, soil science, and troubleshooting
- The 7-step hot-compost system from start to finish
- Bonus tools: troubleshooting chart, safety guide, monitoring log