Weld County, CO — Planting Guide
Weld County is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.
At an elevation of 6,992 ft, Weld County receives approximately 18.8 in of rainfall annually. Summer highs average 87°F with winter lows around 17°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 28 days year to year — ranging from April 21 in warm years to May 19 in cold years. The growing season is trending longer by about 2.43 days per decade. Weld County scores 29/100 (Challenging) on the Microclimate Index.
🌡️ Zone
5a (-20°F to -15°F min)
❄️ Last Frost
May 2
🍂 First Frost
October 7
📅 Growing Season
158 days
⛰️ Elevation
6,992 ft
🌧️ Annual Rainfall
18.8 in
Monthly Watering Calendar
When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering Effort |
|---|---|---|---|---|
| Jan | 1.4 in | 7 days | — | None |
| Feb | 1 in | 5 days | — | None |
| Mar | 1.5 in | 8 days | — | None |
| Apr | 2.1 in | 8 days | 2.2 in | High |
| May | 2.3 in | 9 days | 2 in | High |
| Jun | 1.4 in | 5 days | 2.9 in | High |
| Jul | 1.7 in | 6 days | 2.6 in | High |
| Aug | 1.8 in | 6 days | 2.5 in | High |
| Sep | 1.7 in | 5 days | 2.6 in | High |
| Oct | 1.7 in | 5 days | 2.6 in | High |
| Nov | 1.2 in | 6 days | — | None |
| Dec | 1.1 in | 8 days | — | None |
Annual total: 18.9 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.
Weld County Soil Profile
Soil Type
Loam
Soil pH
6.6-8.1
Drainage
Well Drained
Frost Risk Probability
Based on 31 years of NOAA weather station data from 3 stations
Beginners: Plant frost-sensitive crops (tomatoes, peppers, squash) after the "Safe" date on the left. Harvest or cover them before the "Protect by" date on the right. Hardy crops (lettuce, peas, kale) can go in the yellow transition zones.
How to read this table: "Conservative" means you're safe from frost 9 out of 10 years — best for beginners and frost-sensitive crops. "Average year" is the typical date. "Aggressive" means only 1 in 10 years is that warm — experienced gardeners with frost protection can try these dates.
| Planting Strategy | Last Spring Frost | First Fall Frost | Frost-Free Days |
|---|---|---|---|
| Conservative (safest) | May 19 | Oct 19 | 153 days |
| Cautious | May 10 | Oct 12 | 155 days |
| Average year | May 2 | Oct 7 | 158 days |
| Optimistic | Apr 27 | Oct 2 | 158 days |
| Aggressive (risky) | Apr 21 | Sep 20 | 152 days |
Not very — frost dates can vary by ±28 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 2.4 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Weld County has challenging growing conditions. Season extension and careful variety selection are essential.
Local Gardening Help in Weld 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 Weld County's climate and soil.
County Extension Office
Weld 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 Weld County
Finding local nurseries & garden centers in Weld County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Weld 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 Weld County CO" or "garden center Weld 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 Weld County CO" or check your extension office and local parks department. Facebook groups like "Weld 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
14.9 hours
Summer solstice daylight
Shortest Day
9.1 hours
Winter solstice daylight
Peak Sun Hours
11 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 | 9.4 hr | 5.3 hr | Short day |
| February | 10.4 hr | 6.1 hr | Short day |
| March | 11.7 hr | 6.8 hr | Short day |
| April | 13.1 hr | 7.3 hr | Neutral |
| May | 14.3 hr | 8.6 hr | Long day |
| June | 14.9 hr | 11 hr | Long day |
| July | 14.6 hr | 10.4 hr | Long day |
| August | 13.6 hr | 9.5 hr | Neutral |
| September | 12.3 hr | 8.8 hr | Neutral |
| October | 10.9 hr | 7.4 hr | Short day |
| November | 9.7 hr | 5.8 hr | Short day |
| December | 9.1 hr | 5.2 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 rarely reaches 60°F — use black plastic mulch to warm soil.
Best Month to Compost
Jul
Microbial activity peaks when soil is warm.
Active Composting
3 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 | 3°F | 11°F | ❄️ Dormant | ~36 weeks |
| Feb | 2°F | 8°F | ❄️ Dormant | ~36 weeks |
| Mar | 10°F | 15°F | ❄️ Dormant | ~36 weeks |
| Apr | 25°F | 24°F | ❄️ Dormant | ~36 weeks |
| May | 39°F | 36°F | ❄️ Dormant | ~36 weeks |
| Jun | 50°F | 45°F | 🐢 Slow | ~24 weeks |
| Jul | 57°F | 51°F | ♻️ Active | ~14 weeks |
| Aug | 56°F | 52°F | ♻️ Active | ~14 weeks |
| Sep | 52°F | 48°F | ♻️ Active | ~14 weeks |
| Oct | 37°F | 39°F | ❄️ Dormant | ~36 weeks |
| Nov | 21°F | 28°F | ❄️ Dormant | ~36 weeks |
| Dec | 10°F | 19°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 Weld 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 6 common pests in your area
| Pest | Risk Level | Peak Months |
|---|---|---|
| Aphids | Moderate | May, Jun, Jul, Aug |
| Japanese beetles | Moderate | Jun, Jul, Aug |
| Squash bugs | Low | Jun, Jul, Aug |
| Tomato hornworms | Moderate | Jul, Aug |
| Cabbage loopers | Moderate | May, Jun, Jul, Aug |
| Slugs | Low | Apr, May, Jun |
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 Weld County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
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 14 | Apr 11 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Daikon radish | Aug 15 | Apr 18 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jul 27 | Apr 18 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Aug 27 | Apr 18 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jul 17 | Apr 11 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jul 17 | Apr 11 | — | Erosion control, weed suppression, good biomass |
Spring Cover Crops (3 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | May 12 | Jul 29 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Sorghum-sudan grass | May 14 | Jul 29 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Apr 4 | Aug 12 | ✓ 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 21 | Sep 9 | — | 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: 14 mph
Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.
Windbreak Benefit
6.7/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
High
Hilly terrain with 2,489 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
9,419 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, 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 18.9 inches of rain per year
- A 1,000 sq ft roof can collect roughly 9,419 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 Weld County
Soil Type
Loam
Soil pH 6.6–8.1 · Well Drained drainage
Native soil is well-suited to most vegetables and herbs with regular compost additions.
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
158-day frost-free season
Start warm-season crops indoors and focus on short-season varieties. Cold frames extend your season by 3–4 weeks in fall.
Free Garden Planner
Plan your entire garden season — organize planting dates, track what you're growing, and know exactly when to start seeds, transplant, and harvest.
Recommended for Your Garden
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Get instant, accurate soil pH readings to fine-tune your amendments.
Boost soil fertility and structure with rich, well-aged organic compost.
🥬 Vegetables to Grow in Weld County
106 vegetables that grow well in Zone 5a with planting dates for Weld County.
Show all 106 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Mar 28 | May 9 | May 16 | Aug 8 – Sep 12 | 80–100 |
| Amaranth | Mar 7 | May 9 | May 16 | Aug 15 – Oct 3 | 90–120 |
| Arugula | Mar 28 | Apr 18 | May 2 | Jun 6 – Aug 8 | 30–50 |
| Asparagus | — | — | May 16 | — | 730–1095 |
| Beets | — | Apr 18 | — | Jun 13 – Jul 11 | 50–70 |
| Belgian Endive | Mar 28 | Apr 18 | May 2 | Aug 22 – Oct 17 | 110–150 |
| Bitter Melon | Mar 7 | May 9 | May 16 | Jul 18 – Aug 29 | 60–90 |
| Black Beans | — | May 9 | — | Aug 8 – Sep 26 | 90–120 |
| Bok Choy | Mar 28 | Apr 18 | May 2 | Jun 13 – Jul 18 | 40–60 |
| Broccoli | Mar 28 | Apr 18 | May 2 | Jul 4 – Aug 15 | 60–90 |
| Broccoli Rabe | Mar 28 | Apr 18 | May 2 | Jun 13 – Jul 18 | 40–60 |
| Brussels Sprouts | Mar 28 | Apr 18 | May 2 | Aug 1 – Sep 26 | 90–130 |
| Butternut Squash | Mar 28 | May 9 | May 16 | Aug 15 – Sep 19 | 85–110 |
| Cabbage | Mar 28 | Apr 18 | May 2 | Jul 4 – Aug 29 | 60–100 |
| Calabash | Mar 7 | May 9 | May 16 | Aug 8 – Oct 3 | 80–120 |
| Carrots | — | Apr 18 | — | Jun 20 – Jul 25 | 60–80 |
| Cauliflower | Mar 28 | Apr 18 | May 2 | Jun 27 – Aug 29 | 55–100 |
| Celeriac | Mar 28 | Apr 18 | May 2 | Aug 15 – Sep 19 | 100–120 |
| Celery | Mar 28 | Apr 18 | May 2 | Jul 25 – Sep 19 | 80–120 |
| Celtuce | Mar 28 | Apr 18 | May 2 | Jul 4 – Aug 15 | 60–90 |
| Chard | Mar 28 | Apr 18 | May 2 | Jun 27 – Aug 15 | 50–60 |
| Chickpeas | Mar 28 | Apr 18 | May 2 | Jul 25 – Sep 5 | 80–110 |
| Chicory | Mar 28 | Apr 18 | May 2 | Jul 4 – Aug 15 | 60–85 |
| Chinese Cabbage | Mar 28 | Apr 18 | May 2 | Jun 27 – Jul 25 | 50–70 |
| Christmas Lima Beans | Mar 7 | May 9 | May 16 | Aug 8 – Sep 12 | 80–100 |
| Collard Greens | Mar 28 | Apr 18 | May 2 | Jun 27 – Aug 29 | 55–75 |
| Corn | — | May 9 | — | Jul 11 – Sep 5 | 60–100 |
| Cowpeas | — | May 9 | — | Jul 11 – Aug 22 | 60–90 |
| Cress | Mar 28 | Apr 18 | May 2 | May 16 – Jun 6 | 14–21 |
| Crookneck Squash | Mar 28 | May 9 | May 16 | Jul 4 – Aug 1 | 45–60 |
| Crosne | — | Apr 18 | — | Sep 19 – Oct 3 | 150–200 |
| Cucumber | Mar 28 | May 9 | May 16 | Jul 11 – Sep 5 | 50–70 |
| Daikon | — | Apr 18 | — | Jun 13 – Jul 11 | 50–70 |
| Delicata Squash | Mar 28 | May 9 | May 16 | Aug 8 – Sep 12 | 80–100 |
| Edamame | — | May 9 | — | Jul 25 – Sep 5 | 75–100 |
| Eggplant | Feb 21 | May 9 | May 16 | Jul 25 – Sep 26 | 65–85 |
| Endive | Mar 28 | Apr 18 | May 2 | Jun 20 – Jul 25 | 45–65 |
| Escarole | Mar 28 | Apr 18 | May 2 | Jun 27 – Jul 25 | 50–70 |
| Fava Beans | Mar 28 | Apr 18 | May 2 | Jul 18 – Aug 29 | 75–100 |
| Fennel | Mar 7 | May 9 | May 16 | Jul 18 – Aug 29 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | May 9 | — | Jul 4 – Aug 29 | 50–65 |
| Horseradish | — | — | May 16 | Sep 19 – Oct 31 | 120–180 |
| Hot Peppers | Feb 21 | May 9 | May 16 | Jul 25 – Oct 31 | 70–120 |
| Hubbard Squash | Mar 28 | May 9 | May 16 | Aug 29 – Oct 3 | 100–120 |
| Kabocha | Mar 28 | May 9 | May 16 | Aug 15 – Sep 12 | 85–100 |
| Kai Lan | Mar 28 | Apr 18 | May 2 | Jun 20 – Jul 18 | 45–60 |
| Kale | Mar 28 | Apr 18 | May 2 | Jun 27 – Aug 22 | 50–70 |
| Kidney Beans | — | May 9 | — | Aug 8 – Sep 12 | 85–110 |
| Kohlrabi | Mar 28 | Apr 18 | May 2 | Jun 20 – Jul 25 | 45–65 |
| Komatsuna | Mar 28 | Apr 18 | May 2 | Jun 6 – Jul 11 | 35–50 |
| Leeks | Mar 28 | Apr 18 | May 2 | Aug 1 – Oct 17 | 90–150 |
| Lentils | Mar 28 | Apr 18 | May 2 | Jul 25 – Sep 5 | 80–110 |
| Lettuce | Mar 28 | Apr 18 | May 2 | Jun 6 – Aug 15 | 30–60 |
| Lima Beans | — | May 9 | — | Jul 11 – Aug 22 | 60–90 |
| Mache | Mar 28 | Apr 18 | May 2 | Jun 13 – Jul 18 | 40–60 |
| Melon | Mar 28 | May 9 | May 16 | Jul 25 – Sep 12 | 70–100 |
| Microgreens | Mar 28 | Apr 18 | May 2 | May 9 – Jun 6 | 7–21 |
| Mitsuba | Mar 28 | Apr 18 | Apr 25 | Jun 20 – Aug 15 | 50–70 |
| Mizuna | Mar 28 | Apr 18 | May 2 | Jun 6 – Jul 4 | 30–45 |
| Mustard Greens | Mar 28 | Apr 18 | May 2 | Jun 6 – Aug 8 | 30–50 |
| Napa Cabbage | Mar 28 | Apr 18 | May 2 | Jun 27 – Aug 1 | 55–75 |
| New Zealand Spinach | Mar 7 | May 9 | May 16 | Jul 11 – Aug 8 | 55–70 |
| Okra | Mar 7 | May 9 | May 16 | Jul 11 – Sep 5 | 50–65 |
| Onion | Mar 28 | Apr 18 | May 2 | Aug 1 – Sep 19 | 90–120 |
| Pac Choi | Mar 28 | Apr 18 | May 2 | Jun 13 – Jul 11 | 40–55 |
| Parsnip | — | Apr 18 | — | Aug 1 – Sep 12 | 100–130 |
| Patty Pan Squash | Mar 28 | May 9 | May 16 | Jul 4 – Aug 1 | 45–60 |
| Peas | Mar 28 | Apr 18 | May 2 | Jun 27 – Aug 22 | 55–70 |
| Peppers | Feb 21 | May 9 | May 16 | Jul 18 – Sep 26 | 60–90 |
| Pole Beans | Mar 7 | May 9 | May 16 | Jul 11 – Sep 5 | 55–70 |
| Potatoes | Mar 7 | May 9 | May 16 | Jul 25 – Oct 3 | 70–120 |
| Pumpkin | Mar 28 | May 9 | May 16 | Aug 15 – Oct 3 | 85–120 |
| Purslane | Mar 28 | Apr 18 | May 2 | Jun 13 – Jul 18 | 40–60 |
| Radicchio | Mar 28 | Apr 18 | May 2 | Jul 4 – Aug 8 | 60–80 |
| Radish | — | Apr 18 | — | May 16 – Jun 6 | 22–35 |
| Rhubarb | — | — | May 23 | — | 365–730 |
| Romanesco | Mar 28 | Apr 18 | May 2 | Jul 18 – Aug 29 | 75–100 |
| Rutabaga | — | Apr 18 | — | Jul 11 – Aug 15 | 80–100 |
| Salsify | — | Apr 18 | — | Aug 1 – Sep 12 | 100–130 |
| Savoy Cabbage | Mar 28 | Apr 18 | May 2 | Jul 11 – Sep 5 | 70–110 |
| Scallions | Mar 28 | Apr 18 | May 2 | Jun 27 – Jul 25 | 50–70 |
| Scarlet Runner Beans | Mar 7 | May 9 | May 16 | Jul 18 – Aug 22 | 60–80 |
| Shallot | Mar 28 | Apr 18 | May 2 | Aug 1 – Sep 19 | 90–120 |
| Shiso | Mar 14 | May 9 | May 16 | Jul 11 – Sep 5 | 50–70 |
| Snap Peas | Mar 7 | May 9 | May 16 | Jul 11 – Sep 5 | 55–70 |
| Snow Peas | Mar 28 | Apr 18 | May 2 | Jun 27 – Aug 22 | 50–65 |
| Soybeans | — | May 9 | — | Aug 1 – Sep 26 | 80–120 |
| Spaghetti Squash | Mar 28 | May 9 | May 16 | Aug 15 – Sep 12 | 85–100 |
| Spinach | Mar 28 | Apr 18 | May 2 | Jun 6 – Aug 8 | 35–50 |
| Squash (Summer) | Mar 28 | May 9 | May 16 | Jul 4 – Sep 5 | 45–65 |
| Squash (Winter) | Mar 28 | May 9 | May 16 | Aug 8 – Oct 3 | 80–120 |
| Sunchoke | — | — | May 16 | Sep 5 – Oct 31 | 110–150 |
| Sunflower | Mar 7 | May 9 | May 16 | Jul 25 – Sep 12 | 70–100 |
| Sweet Corn | — | May 9 | — | Jul 11 – Aug 22 | 60–90 |
| Sweet Potatoes | Mar 7 | May 9 | May 16 | Aug 15 – Oct 3 | 90–120 |
| Tatsoi | Mar 28 | Apr 18 | May 2 | Jun 6 – Jul 11 | 35–50 |
| Tomatillo | Mar 7 | May 9 | May 16 | Jul 18 – Sep 26 | 60–85 |
| Tomatoes | Mar 7 | May 9 | May 16 | Jul 18 – Sep 26 | 60–85 |
| Turnip | — | Apr 18 | — | May 30 – Jul 4 | 40–60 |
| Watercress | Mar 28 | Apr 18 | May 2 | Jun 13 – Jul 18 | 40–60 |
| Watermelon | Mar 28 | May 9 | May 16 | Jul 25 – Sep 12 | 70–100 |
| Wax Beans | — | May 9 | — | Jul 4 – Aug 29 | 50–65 |
| Winter Melon | Mar 7 | May 9 | May 16 | Aug 15 – Oct 3 | 90–120 |
| Yard Long Beans | Mar 7 | May 9 | May 16 | Jul 11 – Aug 22 | 55–80 |
| Zucchini | Mar 28 | May 9 | May 16 | Jul 4 – Aug 29 | 45–60 |
🍓 Fruits to Grow in Weld County
27 fruits that grow well in Zone 5a with planting dates for Weld County.
Show all 27 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | May 23 | Aug 22 – Nov 7 | 90–180 |
| Aronia | — | — | May 23 | — | 730–1095 |
| Blackberries | — | — | May 23 | — | 365–730 |
| Blueberries | — | — | May 23 | — | 730–1095 |
| Boysenberries | — | — | May 23 | — | 365–730 |
| Cantaloupe | — | — | May 23 | Aug 1 – Sep 5 | 70–90 |
| Che Fruit | — | — | May 23 | — | 1095–1825 |
| Cranberries | — | — | May 23 | — | 730–1095 |
| Currants | — | — | May 23 | — | 730–1095 |
| Elderberries | — | — | May 23 | — | 730–1095 |
| Goji Berries | — | — | May 23 | — | 730–1095 |
| Gooseberries | — | — | May 23 | — | 730–1095 |
| Grapes | — | — | May 23 | — | 730–1095 |
| Ground Cherry | — | — | May 23 | Aug 1 – Sep 26 | 65–80 |
| Hardy Kiwi | — | — | May 23 | — | 1095–1825 |
| Haskaps | — | — | May 23 | — | 730–1095 |
| Honeydew | — | — | May 23 | Aug 15 – Sep 26 | 80–110 |
| Jostaberry | — | — | May 23 | — | 730–1095 |
| Lingonberries | — | — | May 23 | — | 730–1095 |
| Medlar | — | — | May 23 | — | 1095–1825 |
| Mulberries | — | — | May 23 | — | 730–1825 |
| Pawpaw | — | — | May 23 | — | 1095–2555 |
| Persimmon | — | — | May 23 | — | 1095–2555 |
| Quince | — | — | May 23 | — | 1095–1825 |
| Raspberries | — | — | May 23 | — | 365–730 |
| Serviceberries | — | — | May 23 | — | 730–1095 |
| Strawberries | — | — | May 23 | Aug 22 – Nov 7 | 90–365 |
🌿 Herbs to Grow in Weld County
37 herbs that grow well in Zone 5a with planting dates for Weld County.
Show all 37 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Mar 28 | Apr 18 | Apr 25 | — | 365–730 |
| Anise | Mar 28 | Apr 18 | Apr 25 | Jul 25 – Oct 10 | 90–120 |
| Basil | Mar 14 | May 9 | May 16 | Jul 11 – Sep 12 | 50–75 |
| Bee Balm | — | — | May 9 | Aug 8 – Oct 24 | 90–120 |
| Borage | Mar 28 | Apr 18 | Apr 25 | Jun 20 – Aug 8 | 50–60 |
| Caraway | Mar 28 | Apr 18 | Apr 25 | — | 365–450 |
| Catnip | — | — | May 9 | Jul 11 – Sep 12 | 60–80 |
| Chamomile | Mar 28 | Apr 18 | Apr 25 | Jun 27 – Sep 5 | 60–90 |
| Chervil | Mar 28 | Apr 18 | Apr 25 | Jun 6 – Aug 8 | 40–60 |
| Chives | — | — | May 9 | Jul 11 – Sep 19 | 60–90 |
| Cilantro | Mar 28 | Apr 18 | Apr 25 | Jun 6 – Aug 8 | 40–60 |
| Comfrey | — | — | May 9 | Jul 11 – Sep 19 | 60–90 |
| Cumin | Mar 28 | Apr 18 | Apr 25 | Aug 8 – Oct 10 | 100–120 |
| Dill | Mar 28 | Apr 18 | Apr 25 | Jun 6 – Aug 8 | 40–60 |
| Echinacea | — | — | May 9 | Sep 12 – Oct 24 | 120–180 |
| Epazote | Mar 14 | May 9 | May 16 | Jul 4 – Aug 29 | 45–60 |
| Fennel (herb) | Mar 28 | Apr 18 | Apr 25 | Jun 27 – Sep 5 | 60–90 |
| Feverfew | — | — | May 9 | Aug 8 – Oct 24 | 90–120 |
| Garlic Chives | — | — | May 9 | Jul 11 – Sep 19 | 60–90 |
| Horehound | — | — | May 9 | Jul 25 – Sep 19 | 75–90 |
| Hyssop | — | — | May 9 | Jul 18 – Sep 19 | 70–90 |
| Lavender | — | — | May 9 | Aug 8 – Oct 24 | 90–200 |
| Lemon Balm | — | — | May 9 | Jul 11 – Aug 29 | 60–70 |
| Lemon Thyme | — | — | May 9 | Jul 18 – Sep 19 | 70–90 |
| Lovage | — | — | May 9 | Jul 18 – Sep 19 | 70–90 |
| Mint | — | — | May 9 | Jul 11 – Sep 19 | 60–90 |
| Oregano | — | — | May 9 | Jul 11 – Sep 19 | 60–90 |
| Parsley | Mar 28 | Apr 18 | Apr 25 | Jun 27 – Aug 29 | 60–80 |
| Rue | — | — | May 9 | Jul 18 – Sep 19 | 70–90 |
| Sage | — | — | May 9 | Jul 25 – Sep 19 | 75–90 |
| Savory | — | — | May 9 | Jul 4 – Aug 29 | 50–70 |
| Sorrel | Mar 28 | Apr 18 | Apr 25 | Jun 6 – Aug 8 | 40–60 |
| Tarragon | — | — | May 9 | Jul 11 – Sep 19 | 60–90 |
| Thai Basil | Mar 14 | May 9 | May 16 | Jul 11 – Sep 12 | 50–75 |
| Thyme | — | — | May 9 | Jul 18 – Sep 19 | 70–90 |
| Valerian | — | — | May 9 | Sep 12 – Oct 24 | 120–180 |
| Yarrow | — | — | May 9 | Aug 8 – Oct 24 | 90–120 |
Monthly Planting Guide for Weld County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Weld County.
Frequently Asked Questions
What planting zone is Weld County, CO?
Weld County is in USDA Hardiness Zone 5a. 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 Weld County, CO?
Based on 31 years of NOAA weather station data, the median last spring frost in Weld County falls around May 2. In 8 out of 10 years, last frost lands between April 21 and May 19 — a 28-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 Weld County, CO?
The median first fall frost in Weld County arrives around October 7. In cold years it can arrive as early as September 20; 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 Weld County?
Weld County has a frost-free growing season of approximately 158 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 2.43 days per decade.
What is the soil like in Weld County for gardening?
Weld County has predominantly Loam soil with a pH range of 6.6–8.1 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Weld County?
Weld 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 Weld County a good location for home gardening?
Weld 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 Weld County gardeners in Zone 5a 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.
