Harper County, OK — Planting Guide
Your June game plan for Harper County, Oklahoma
June is a pivotal month for Harper County, Oklahoma gardens. Focus on these tasks first and you'll set up the rest of the season for success.
-
Start basil, peppers, and pole beans indoors
These need a head start before your last frost (April 15). Sow into cells now so you're ready to transplant in a few weeks.
-
It's harvest week for basil, carrots, and cucumber
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
July will be here before you know it — start on
- First harvests: basil, carrots, and cucumber
Harper County is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 18, giving you a growing season of approximately 186 days.
At an elevation of 861 ft, Harper County receives approximately 21.5 in of rainfall annually. Summer highs average 89°F with winter lows around 20°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 3 in warm years to May 1 in cold years. The growing season is trending longer by about 1.77 days per decade. Harper County scores 53/100 (Moderate) on the Microclimate Index.
🌡️ Zone
7a (0°F to 5°F min)
❄️ Last Frost
April 15
🍂 First Frost
October 18
📅 Growing Season
186 days
⛰️ Elevation
861 ft
🌧️ Annual Rainfall
21.5 in
Monthly Watering Calendar for Harper County
When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.
Quick context: Mulch reduces watering needs 30-50% by cutting evaporation. Harper County's 22" annual rainfall might be enough for vegetables in some months and not in others — a 2-3" mulch layer evens the swing.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering Effort |
|---|---|---|---|---|
| Jan | 0.5 in | 3 days | — | None |
| Feb | 0.7 in | 4 days | — | None |
| Mar | 1.3 in | 6 days | 3 in | High |
| Apr | 2.2 in | 7 days | 2.1 in | High |
| May | 3.2 in | 9 days | 1.1 in | Moderate |
| Jun | 3.9 in | 9 days | 0.4 in | Low |
| Jul | 2.9 in | 7 days | 1.4 in | Moderate |
| Aug | 2.3 in | 7 days | 2 in | High |
| Sep | 2 in | 6 days | 2.3 in | High |
| Oct | 1.3 in | 5 days | 3 in | High |
| Nov | 0.7 in | 4 days | — | None |
| Dec | 0.5 in | 3 days | — | None |
Annual total: 21.5 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.
Harper County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.2
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 1 | Nov 2 | 185 days |
| Cautious | Apr 23 | Oct 24 | 184 days |
| Average year | Apr 15 | Oct 18 | 186 days |
| Optimistic | Apr 13 | Oct 11 | 181 days |
| Aggressive (risky) | Apr 3 | Oct 3 | 183 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 1.8 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Harper County presents some gardening challenges. Choose adapted varieties and plan around frost dates.
Local Gardening Help in Harper 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 Harper County's climate and soil.
County Extension Office
Harper County Oklahoma State University Extension Extension Office
Phone: 405-744-5398
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 Harper County
Finding local nurseries & garden centers in Harper County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Harper 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 Harper County OK" or "garden center Harper 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 Harper County OK" or check your extension office and local parks department. Facebook groups like "Harper County Gardeners" or "Oklahoma 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 in Harper County
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
Quick context: A 14-hour day in June produces dramatically more photosynthesis than a 10-hour day in November. Harper County's seasonal swing determines which crops can pack growth into spring vs. limp through fall.
Longest Day
14.5 hours
Summer solstice daylight
Shortest Day
9.5 hours
Winter solstice daylight
Peak Sun Hours
10.3 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 | 9.7 hr | 5.3 hr | Short day |
| February | 10.6 hr | 5.9 hr | Short day |
| March | 11.7 hr | 6.9 hr | Short day |
| April | 12.9 hr | 7.9 hr | Neutral |
| May | 14 hr | 8.7 hr | Long day |
| June | 14.5 hr | 10 hr | Long day |
| July | 14.3 hr | 10.3 hr | Long day |
| August | 13.4 hr | 9.1 hr | Neutral |
| September | 12.2 hr | 8.3 hr | Neutral |
| October | 11 hr | 7 hr | Short day |
| November | 10 hr | 6.1 hr | Short day |
| December | 9.5 hr | 5.4 hr | Short day |
Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.
Soil Temperature & Composting in Harper County
Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.
The practical takeaway: Most root crops germinate well at 50-60°F. Most fruit-bearing crops want 65-75°F. Harper County's monthly soil curve maps these windows to actual months.
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
7 months
Solid season. Piles go dormant in winter.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 31°F | 38°F | ❄️ Dormant | ~36 weeks |
| Feb | 32°F | 38°F | ❄️ Dormant | ~36 weeks |
| Mar | 40°F | 43°F | 🐢 Slow | ~24 weeks |
| Apr | 52°F | 50°F | ♻️ Active | ~14 weeks |
| May | 64°F | 60°F | ♻️ Active | ~14 weeks |
| Jun | 76°F | 70°F | 🔥 Peak | ~8 weeks |
| Jul | 83°F | 76°F | 🔥 Peak | ~8 weeks |
| Aug | 82°F | 79°F | 🔥 Peak | ~8 weeks |
| Sep | 77°F | 76°F | 🔥 Peak | ~8 weeks |
| Oct | 64°F | 67°F | ♻️ Active | ~14 weeks |
| Nov | 50°F | 56°F | 🐢 Slow | ~24 weeks |
| Dec | 36°F | 44°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 Harper County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
Why this matters: Two gardeners can grow identical seeds and get wildly different results based on pest pressure alone. Harper County's climate sets a floor on what's possible without intervention.
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 | 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 | Low | 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 Harper County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with planting dates calibrated for your area.
What this means for you: Cover crops fix nitrogen by hosting bacteria that pull it from the air. A vigorous legume cover crop can deliver 50-150 lbs/acre of nitrogen — meaningful for the next vegetable season.
Spring Cover Crops (3 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | Apr 21 | Aug 16 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Sorghum-sudan grass | Apr 24 | Aug 23 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Mar 19 | Aug 9 | ✓ 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 7 | Sep 20 | — | 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 25 | Apr 1 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Crimson clover | Aug 23 | Apr 1 | ✓ Yes | Fixes nitrogen, attracts pollinators in spring |
| Daikon radish | Aug 31 | Mar 25 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jul 24 | Mar 25 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Sep 9 | Mar 25 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jul 21 | Mar 25 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jul 14 | Mar 25 | — | Erosion control, weed suppression, good biomass |
Wind & Microclimate in Harper County
Why it matters: Wind shapes the garden you don't think about: bee paths, evaporation, structural stress on tomato cages. Harper County's 11.3 mph background level is a baseline you should know before placing the tallest crops (sunflowers, pole beans, sweet corn).
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: 12 mph Winter: 15 mph
Prevailing wind: S. Windy area — plant a windbreak hedge on the S 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
Low
Relatively flat terrain (302 ft range). Frost pocket risk is minimal — garden placement is flexible.
Rainwater Harvesting in Harper County
How much water you can collect, when to collect it, and what size system you need for your garden.
Why it matters: The first inch of rain washes the roof clean — a first-flush diverter sends it to waste before the barrel fills. Worth the extra $20 for cleaner garden water. Harper County gets 22" annually, so you'll fill and flush many times per year.
Annual Collection
10,715 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 2,250 gal tank.
Legal Status
Unrestricted
Rainwater harvesting is fully legal in your state with no restrictions.
Best Collection Months
May, Jun, Jul, Aug
Highest rainfall months — your barrels will fill up quickly during these months.
Months to Draw From Storage
Jan, Feb, 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 21.5 inches of rain per year
- A 1,000 sq ft roof can collect roughly 10,715 gallons annually
- Rainwater harvesting is fully legal in your state
- Stock up on stored water before your dry season (Jan, Feb, Nov)
- Use a first-flush diverter to keep roof debris out of your collection
Soil & Growing Conditions in Harper County
Soil Type
Loam
Soil pH 6.4–7.2 · 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
186-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.
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.
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 Harper County
112 vegetables that grow well in Zone 7a with planting dates for Harper County.
Show all 112 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Fall Plant | Harvest | Days to Maturity |
|---|---|---|---|---|---|---|
| Acorn Squash | Mar 18 | Apr 22 | Apr 29 | — | Jul 22 – Aug 26 | 80–100 |
| Amaranth | Feb 25 | Apr 22 | Apr 29 | — | Jul 29 – Sep 16 | 90–120 |
| Artichoke | — | — | Apr 29 | — | Sep 2 – Nov 11 | 120–180 |
| Arugula | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 20 – Jul 22 | 30–50 |
| Asparagus | — | — | Apr 29 | — | — | 730–1095 |
| Beets | — | Apr 1 | — | Aug 9 | May 27 – Jun 24 | 50–70 |
| Belgian Endive | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Aug 5 – Sep 30 | 110–150 |
| Bitter Melon | Feb 25 | Apr 22 | Apr 29 | — | Jul 1 – Aug 12 | 60–90 |
| Black Beans | — | Apr 22 | — | — | Jul 22 – Sep 9 | 90–120 |
| Bok Choy | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 27 – Jul 1 | 40–60 |
| Broccoli | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 17 – Jul 29 | 60–90 |
| Broccoli Rabe | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 27 – Jul 1 | 40–60 |
| Brussels Sprouts | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 15 – Sep 9 | 90–130 |
| Butternut Squash | Mar 18 | Apr 22 | Apr 29 | — | Jul 29 – Sep 2 | 85–110 |
| Cabbage | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 17 – Aug 12 | 60–100 |
| Calabash | Feb 25 | Apr 22 | Apr 29 | — | Jul 22 – Sep 16 | 80–120 |
| Cardoon | — | — | Apr 29 | — | Sep 2 – Oct 14 | 120–150 |
| Carrots | — | Apr 1 | — | Aug 9 | Jun 3 – Jul 8 | 60–80 |
| Cauliflower | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Aug 12 | 55–100 |
| Celeriac | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 29 – Sep 2 | 100–120 |
| Celery | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 8 – Sep 2 | 80–120 |
| Celtuce | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 17 – Jul 29 | 60–90 |
| Chard | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Jul 29 | 50–60 |
| Chayote | Feb 25 | Apr 22 | Apr 29 | — | Sep 2 – Nov 11 | 120–180 |
| Chickpeas | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 8 – Aug 19 | 80–110 |
| Chicory | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 17 – Jul 29 | 60–85 |
| Chinese Cabbage | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Jul 8 | 50–70 |
| Christmas Lima Beans | Feb 25 | Apr 22 | Apr 29 | — | Jul 22 – Aug 26 | 80–100 |
| Collard Greens | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Aug 12 | 55–75 |
| Corn | — | Apr 22 | — | — | Jun 24 – Aug 19 | 60–100 |
| Cowpeas | — | Apr 22 | — | — | Jun 24 – Aug 5 | 60–90 |
| Cress | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Apr 29 – May 20 | 14–21 |
| Crookneck Squash | Mar 18 | Apr 22 | Apr 29 | — | Jun 17 – Jul 15 | 45–60 |
| Crosne | — | Apr 1 | — | Aug 9 | Sep 2 – Nov 4 | 150–200 |
| Cucumber | Mar 18 | Apr 22 | Apr 29 | — | Jun 24 – Aug 19 | 50–70 |
| Daikon | — | Apr 1 | — | Aug 9 | May 27 – Jun 24 | 50–70 |
| Delicata Squash | Mar 18 | Apr 22 | Apr 29 | — | Jul 22 – Aug 26 | 80–100 |
| Edamame | — | Apr 22 | — | — | Jul 8 – Aug 19 | 75–100 |
| Eggplant | Feb 11 | Apr 22 | Apr 29 | — | Jul 8 – Sep 9 | 65–85 |
| Endive | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 3 – Jul 8 | 45–65 |
| Escarole | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Jul 8 | 50–70 |
| Fava Beans | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 1 – Aug 12 | 75–100 |
| Fennel | Feb 25 | Apr 22 | Apr 29 | — | Jul 1 – Aug 12 | 60–90 |
| Garlic | — | — | — | Sep 6 | Dec 6 – Apr 18 | 90–240 |
| Green Beans | — | Apr 22 | — | — | Jun 17 – Aug 12 | 50–65 |
| Horseradish | — | — | Apr 29 | — | Sep 2 – Nov 11 | 120–180 |
| Hot Peppers | Feb 11 | Apr 22 | Apr 29 | — | Jul 8 – Oct 14 | 70–120 |
| Hubbard Squash | Mar 18 | Apr 22 | Apr 29 | — | Aug 12 – Sep 16 | 100–120 |
| Jicama | Feb 25 | Apr 22 | Apr 29 | — | Sep 2 – Nov 11 | 120–180 |
| Kabocha | Mar 18 | Apr 22 | Apr 29 | — | Jul 29 – Aug 26 | 85–100 |
| Kai Lan | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 3 – Jul 1 | 45–60 |
| Kale | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Aug 5 | 50–70 |
| Kidney Beans | — | Apr 22 | — | — | Jul 22 – Aug 26 | 85–110 |
| Kohlrabi | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 3 – Jul 8 | 45–65 |
| Komatsuna | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 20 – Jun 24 | 35–50 |
| Leeks | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 15 – Sep 30 | 90–150 |
| Lentils | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 8 – Aug 19 | 80–110 |
| Lettuce | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 20 – Jul 29 | 30–60 |
| Lima Beans | — | Apr 22 | — | — | Jun 24 – Aug 5 | 60–90 |
| Loofah | Feb 25 | Apr 22 | Apr 29 | — | Aug 12 – Oct 14 | 100–150 |
| Luffa | Feb 25 | Apr 22 | Apr 29 | — | Jul 29 – Oct 14 | 90–150 |
| Mache | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 27 – Jul 1 | 40–60 |
| Malabar Spinach | Feb 25 | Apr 22 | Apr 29 | — | Jun 24 – Jul 22 | 55–70 |
| Melon | Mar 18 | Apr 22 | Apr 29 | — | Jul 8 – Aug 26 | 70–100 |
| Microgreens | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Apr 22 – May 20 | 7–21 |
| Mitsuba | Mar 11 | Apr 1 | Apr 8 | Aug 9 | Jun 3 – Jul 29 | 50–70 |
| Mizuna | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 20 – Jun 17 | 30–45 |
| Mustard Greens | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 20 – Jul 22 | 30–50 |
| Napa Cabbage | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Jul 15 | 55–75 |
| New Zealand Spinach | Feb 25 | Apr 22 | Apr 29 | — | Jun 24 – Jul 22 | 55–70 |
| Okra | Feb 25 | Apr 22 | Apr 29 | — | Jun 24 – Aug 19 | 50–65 |
| Onion | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 15 – Sep 2 | 90–120 |
| Pac Choi | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 27 – Jun 24 | 40–55 |
| Parsnip | — | Apr 1 | — | Aug 9 | Jul 15 – Aug 26 | 100–130 |
| Patty Pan Squash | Mar 18 | Apr 22 | Apr 29 | — | Jun 17 – Jul 15 | 45–60 |
| Peas | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Aug 5 | 55–70 |
| Peppers | Feb 11 | Apr 22 | Apr 29 | — | Jul 1 – Sep 9 | 60–90 |
| Pole Beans | Feb 25 | Apr 22 | Apr 29 | — | Jun 24 – Aug 19 | 55–70 |
| Potatoes | Feb 25 | Apr 22 | Apr 29 | — | Jul 8 – Sep 16 | 70–120 |
| Pumpkin | Mar 18 | Apr 22 | Apr 29 | — | Jul 29 – Sep 16 | 85–120 |
| Purslane | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 27 – Jul 1 | 40–60 |
| Radicchio | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 17 – Jul 22 | 60–80 |
| Radish | — | Apr 1 | — | Aug 9 | Apr 29 – May 20 | 22–35 |
| Rhubarb | — | — | May 6 | — | — | 365–730 |
| Romanesco | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 1 – Aug 12 | 75–100 |
| Rutabaga | — | Apr 1 | — | Aug 9 | Jun 24 – Jul 29 | 80–100 |
| Salsify | — | Apr 1 | — | Aug 9 | Jul 15 – Aug 26 | 100–130 |
| Savoy Cabbage | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 24 – Aug 19 | 70–110 |
| Scallions | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Jul 8 | 50–70 |
| Scarlet Runner Beans | Feb 25 | Apr 22 | Apr 29 | — | Jul 1 – Aug 5 | 60–80 |
| Shallot | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jul 15 – Sep 2 | 90–120 |
| Shiso | Feb 25 | Apr 22 | Apr 29 | — | Jun 24 – Aug 19 | 50–70 |
| Snap Peas | Feb 25 | Apr 22 | Apr 29 | — | Jun 24 – Aug 19 | 55–70 |
| Snow Peas | Mar 11 | Apr 1 | Apr 15 | Aug 9 | Jun 10 – Aug 5 | 50–65 |
| Soybeans | — | Apr 22 | — | — | Jul 15 – Sep 9 | 80–120 |
| Spaghetti Squash | Mar 18 | Apr 22 | Apr 29 | — | Jul 29 – Aug 26 | 85–100 |
| Spinach | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 20 – Jul 22 | 35–50 |
| Squash (Summer) | Mar 18 | Apr 22 | Apr 29 | — | Jun 17 – Aug 19 | 45–65 |
| Squash (Winter) | Mar 18 | Apr 22 | Apr 29 | — | Jul 22 – Sep 16 | 80–120 |
| Sunchoke | — | — | Apr 29 | — | Aug 19 – Oct 14 | 110–150 |
| Sweet Corn | — | Apr 22 | — | — | Jun 24 – Aug 5 | 60–90 |
| Sweet Potatoes | Feb 25 | Apr 22 | Apr 29 | — | Jul 29 – Sep 16 | 90–120 |
| Tatsoi | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 20 – Jun 24 | 35–50 |
| Tomatillo | Feb 25 | Apr 22 | Apr 29 | — | Jul 1 – Sep 9 | 60–85 |
| Tomatoes | Feb 25 | Apr 22 | Apr 29 | — | Jul 1 – Sep 9 | 60–85 |
| Turnip | — | Apr 1 | — | Aug 9 | May 13 – Jun 17 | 40–60 |
| Watercress | Mar 11 | Apr 1 | Apr 15 | Aug 9 | May 27 – Jul 1 | 40–60 |
| Watermelon | Mar 18 | Apr 22 | Apr 29 | — | Jul 8 – Aug 26 | 70–100 |
| Wax Beans | — | Apr 22 | — | — | Jun 17 – Aug 12 | 50–65 |
| Winter Melon | Feb 25 | Apr 22 | Apr 29 | — | Jul 29 – Sep 16 | 90–120 |
| Yard Long Beans | Feb 25 | Apr 22 | Apr 29 | — | Jun 24 – Aug 5 | 55–80 |
| Zucchini | Mar 18 | Apr 22 | Apr 29 | — | Jun 17 – Aug 12 | 45–60 |
🍓 Fruits to Grow in Harper County
31 fruits that grow well in Zone 7a with planting dates for Harper County.
Show all 31 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Fall Plant | Harvest | Days to Maturity |
|---|---|---|---|---|---|---|
| Alpine Strawberries | — | — | May 6 | — | Aug 5 – Nov 18 | 90–180 |
| Aronia | — | — | May 6 | — | — | 730–1095 |
| Blackberries | — | — | May 6 | — | — | 365–730 |
| Blueberries | — | — | May 6 | — | — | 730–1095 |
| Boysenberries | — | — | May 6 | — | — | 365–730 |
| Cantaloupe | — | — | May 6 | — | Jul 15 – Aug 19 | 70–90 |
| Che Fruit | — | — | May 6 | — | — | 1095–1825 |
| Cranberries | — | — | May 6 | — | — | 730–1095 |
| Currants | — | — | May 6 | — | — | 730–1095 |
| Elderberries | — | — | May 6 | — | — | 730–1095 |
| Figs | — | — | May 6 | — | — | 730–1825 |
| Goji Berries | — | — | May 6 | — | — | 730–1095 |
| Gooseberries | — | — | May 6 | — | — | 730–1095 |
| Grapes | — | — | May 6 | — | — | 730–1095 |
| Ground Cherry | — | — | May 6 | — | Jul 15 – Sep 9 | 65–80 |
| Hardy Kiwi | — | — | May 6 | — | — | 1095–1825 |
| Haskaps | — | — | May 6 | — | — | 730–1095 |
| Honeydew | — | — | May 6 | — | Jul 29 – Sep 9 | 80–110 |
| Jostaberry | — | — | May 6 | — | — | 730–1095 |
| Kiwi | — | — | May 6 | — | — | 1095–1825 |
| Lingonberries | — | — | May 6 | — | — | 730–1095 |
| Loquat | — | — | May 6 | — | — | 730–1825 |
| Medlar | — | — | May 6 | — | — | 1095–1825 |
| Mulberries | — | — | May 6 | — | — | 730–1825 |
| Pawpaw | — | — | May 6 | — | — | 1095–2555 |
| Persimmon | — | — | May 6 | — | — | 1095–2555 |
| Pomegranate | — | — | May 6 | — | — | 730–1095 |
| Quince | — | — | May 6 | — | — | 1095–1825 |
| Raspberries | — | — | May 6 | — | — | 365–730 |
| Serviceberries | — | — | May 6 | — | — | 730–1095 |
| Strawberries | — | — | May 6 | — | Aug 5 – Dec 16 | 90–365 |
🌿 Herbs to Grow in Harper County
36 herbs that grow well in Zone 7a with planting dates for Harper County.
Show all 36 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Fall Plant | Harvest | Days to Maturity |
|---|---|---|---|---|---|---|
| Angelica | Mar 11 | Apr 1 | Apr 8 | Aug 9 | — | 365–730 |
| Anise | Mar 11 | Apr 1 | Apr 8 | Aug 9 | Jul 8 – Sep 23 | 90–120 |
| Basil | Feb 25 | Apr 22 | Apr 29 | — | Jun 24 – Aug 26 | 50–75 |
| Bee Balm | — | — | Apr 22 | — | Jul 22 – Oct 7 | 90–120 |
| Borage | Mar 11 | Apr 1 | Apr 8 | Aug 9 | Jun 3 – Jul 22 | 50–60 |
| Caraway | Mar 11 | Apr 1 | Apr 8 | Aug 9 | — | 365–450 |
| Catnip | — | — | Apr 22 | — | Jun 24 – Aug 26 | 60–80 |
| Chamomile | Mar 11 | Apr 1 | Apr 8 | Aug 9 | Jun 10 – Aug 19 | 60–90 |
| Chervil | Mar 11 | Apr 1 | Apr 8 | Aug 9 | May 20 – Jul 22 | 40–60 |
| Chives | — | — | Apr 22 | — | Jun 24 – Sep 2 | 60–90 |
| Cilantro | Mar 11 | Apr 1 | Apr 8 | Aug 9 | May 20 – Jul 22 | 40–60 |
| Comfrey | — | — | Apr 22 | — | Jun 24 – Sep 2 | 60–90 |
| Cumin | Mar 11 | Apr 1 | Apr 8 | Aug 9 | Jul 22 – Sep 23 | 100–120 |
| Dill | Mar 11 | Apr 1 | Apr 8 | Aug 9 | May 20 – Jul 22 | 40–60 |
| Epazote | Feb 25 | Apr 22 | Apr 29 | — | Jun 17 – Aug 12 | 45–60 |
| Fennel (herb) | Mar 11 | Apr 1 | Apr 8 | Aug 9 | Jun 10 – Aug 19 | 60–90 |
| Feverfew | — | — | Apr 22 | — | Jul 22 – Oct 7 | 90–120 |
| Garlic Chives | — | — | Apr 22 | — | Jun 24 – Sep 2 | 60–90 |
| Horehound | — | — | Apr 22 | — | Jul 8 – Sep 2 | 75–90 |
| Hyssop | — | — | Apr 22 | — | Jul 1 – Sep 2 | 70–90 |
| Lemon Balm | — | — | Apr 22 | — | Jun 24 – Aug 12 | 60–70 |
| Lemon Thyme | — | — | Apr 22 | — | Jul 1 – Sep 2 | 70–90 |
| Lovage | — | — | Apr 22 | — | Jul 1 – Sep 2 | 70–90 |
| Marjoram | — | — | Apr 22 | — | Jun 24 – Sep 2 | 60–90 |
| Mint | — | — | Apr 22 | — | Jun 24 – Sep 2 | 60–90 |
| Oregano | — | — | Apr 22 | — | Jun 24 – Sep 2 | 60–90 |
| Parsley | Mar 11 | Apr 1 | Apr 8 | Aug 9 | Jun 10 – Aug 12 | 60–80 |
| Rosemary | — | — | Apr 22 | — | Jul 15 – Dec 2 | 80–180 |
| Rue | — | — | Apr 22 | — | Jul 1 – Sep 2 | 70–90 |
| Sage | — | — | Apr 22 | — | Jul 8 – Sep 2 | 75–90 |
| Savory | — | — | Apr 22 | — | Jun 17 – Aug 12 | 50–70 |
| Sorrel | Mar 11 | Apr 1 | Apr 8 | Aug 9 | May 20 – Jul 22 | 40–60 |
| Tarragon | — | — | Apr 22 | — | Jun 24 – Sep 2 | 60–90 |
| Thai Basil | Feb 25 | Apr 22 | Apr 29 | — | Jun 24 – Aug 26 | 50–75 |
| Thyme | — | — | Apr 22 | — | Jul 1 – Sep 2 | 70–90 |
| Valerian | — | — | Apr 22 | — | Aug 26 – Dec 2 | 120–180 |
🌸 Flowers to Grow in Harper County
53 flowers that grow well in Zone 7a with planting dates for Harper County.
Show all 53 flowers with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Fall Plant | Bloom | Days to Maturity |
|---|---|---|---|---|---|---|
| Ageratum | Mar 4 | Apr 15 | Apr 15 | — | Jun 10 – Sep 30 | 60–75 |
| Alliums | — | — | — | Sep 13 | Oct 11 – Nov 1 | 28–42 |
| Anemones | — | — | — | Aug 23 | Sep 6 – Oct 4 | 90–120 |
| Astilbe | Feb 11 | — | Apr 22 | — | Jul 1 – Aug 26 | 70–100 |
| Bachelor's Button | Mar 4 | Mar 11 | Apr 15 | Aug 23 | Jun 17 – Sep 16 | 60–90 |
| Begonias | Feb 4 | — | Apr 15 | — | Jun 24 – Oct 14 | 70–90 |
| Black-eyed Susan | Feb 11 | Apr 15 | Apr 22 | — | Jul 1 – Nov 4 | 60–80 |
| Bleeding Hearts | Feb 11 | — | Apr 22 | — | Jun 10 – Jul 15 | 60–90 |
| Calendula | Mar 4 | Mar 11 | Apr 15 | Aug 23 | Jun 3 – Sep 16 | 50–70 |
| California Poppy | — | Mar 18 | — | Aug 23 | May 27 – Aug 5 | 60–90 |
| Celosia | Mar 18 | Apr 15 | Apr 15 | — | Jun 17 – Oct 14 | 60–90 |
| Columbine | Feb 18 | Apr 22 | Apr 22 | — | Jun 10 – Jul 15 | 70–100 |
| Coreopsis | Feb 11 | Apr 15 | Apr 22 | — | Jun 24 – Nov 4 | 60–80 |
| Cosmos | Mar 18 | Apr 15 | Apr 15 | — | Jun 24 – Oct 14 | 60–90 |
| Crocus | — | — | — | Sep 13 | Aug 9 – Aug 30 | 10–20 |
| Daffodils | — | — | — | Sep 13 | Aug 16 – Sep 6 | 20–40 |
| Dahlias | Mar 18 | Apr 22 | Apr 22 | — | Jul 1 – Nov 4 | 70–120 |
| Daylily | Feb 11 | — | Apr 22 | — | Jul 1 – Nov 4 | 60–90 |
| Dianthus | Feb 18 | Mar 11 | Mar 25 | — | May 13 – Aug 12 | 60–80 |
| Echinacea (Purple Coneflower) | Feb 11 | Apr 22 | Apr 22 | — | Jul 8 – Nov 4 | 70–90 |
| Foxglove | Feb 18 | Apr 22 | Apr 22 | — | Jun 10 – Jul 15 | 80–120 |
| Gaillardia (Blanket Flower) | Feb 25 | Apr 22 | Apr 22 | — | Jul 1 – Nov 18 | 70–100 |
| Geraniums | Feb 4 | — | Apr 15 | — | Jun 24 – Oct 14 | 70–100 |
| Gladiolus | — | Apr 15 | Apr 15 | — | Jun 24 – Oct 28 | 70–100 |
| Hostas | Feb 4 | — | Apr 22 | — | Jul 1 – Nov 4 | 60–90 |
| Hyacinths | — | — | — | Sep 13 | Sep 6 – Sep 27 | 14–28 |
| Hydrangeas | Feb 4 | — | Apr 22 | — | Jul 1 – Oct 21 | 90–150 |
| Impatiens | Feb 18 | — | Apr 22 | — | Jul 1 – Oct 21 | 60–75 |
| Irises | — | Division | Apr 22 | — | Jun 10 – Jul 15 | 60–100 |
| Larkspur | — | Mar 18 | — | Aug 9 | May 27 – Aug 5 | 60–90 |
| Lavender | Feb 11 | — | Apr 29 | — | Jul 8 – Sep 16 | 90–120 |
| Lilies | — | Division | Apr 22 | — | Jul 1 – Oct 21 | 70–120 |
| Lobelia | Feb 11 | — | Mar 25 | — | May 20 – Aug 12 | 70–80 |
| Lupine | Feb 18 | Apr 22 | Apr 22 | — | Jun 10 – Jul 15 | 75–100 |
| Marigolds | Mar 4 | Apr 15 | Apr 15 | — | Jun 10 – Sep 16 | 50–70 |
| Nasturtium | Mar 18 | Apr 15 | Apr 15 | — | Jun 10 – Oct 14 | 55–65 |
| Pansy | Feb 4 | — | Apr 15 | Aug 9 | Jun 10 – Aug 19 | 70–90 |
| Peonies | — | Division | Apr 22 | — | Jun 17 – Jul 22 | 90–120 |
| Petunia | Feb 18 | — | Apr 22 | — | Jul 1 – Oct 21 | 70–90 |
| Phlox | Feb 11 | Apr 22 | Apr 22 | — | Jul 1 – Sep 23 | 80–110 |
| Portulaca | Mar 18 | Apr 15 | Apr 15 | — | Jun 3 – Sep 30 | 50–70 |
| Ranunculus | — | — | — | Aug 23 | Sep 20 – Oct 18 | 90–120 |
| Roses | Feb 4 | — | Apr 22 | — | Jul 1 – Nov 4 | 90–180 |
| Salvia | Feb 18 | — | Apr 15 | — | Jun 24 – Oct 14 | 70–90 |
| Sedum (Stonecrop) | Feb 11 | — | Apr 22 | — | Aug 12 – Nov 4 | 60–90 |
| Snapdragon | Feb 4 | Mar 18 | Apr 15 | Aug 23 | Jun 24 – Sep 16 | 70–100 |
| Sunflower | Mar 25 | Apr 15 | Apr 15 | — | Jul 8 – Oct 14 | 70–100 |
| Sweet Alyssum | Mar 4 | Mar 18 | Apr 15 | Sep 6 | May 27 – Aug 19 | 45–60 |
| Sweet Pea | — | Mar 11 | — | Aug 23 | May 20 – Aug 12 | 65–85 |
| Tulips | — | — | — | Sep 13 | Aug 30 – Sep 20 | 15–30 |
| Vinca (Annual) | Feb 4 | — | Apr 15 | — | Jun 24 – Oct 14 | 70–90 |
| Yarrow | Feb 11 | Apr 15 | Apr 22 | — | Jun 24 – Nov 4 | 60–90 |
| Zinnia | Mar 18 | Apr 15 | Apr 15 | — | Jun 24 – Oct 14 | 60–70 |
Monthly Planting Guide for Harper County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Harper County.
Frequently Asked Questions
What planting zone is Harper County, OK?
Harper County is in USDA Hardiness Zone 7a. 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 Harper County, OK?
Based on 31 years of NOAA weather station data, the median last spring frost in Harper County falls around April 15. In 8 out of 10 years, last frost lands between April 3 and May 1 — a 28-day window of variability. Use May 1 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Harper County, OK?
The median first fall frost in Harper County arrives around October 18. In cold years it can arrive as early as October 3; in mild years as late as November 2. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Harper County?
Harper County has a frost-free growing season of approximately 186 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 1.77 days per decade.
What is the soil like in Harper County for gardening?
Harper County has predominantly Loam soil with a pH range of 6.4–7.2 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Harper County?
Harper County has commercial agriculture that includes Wheat, Cattle, Hay, Sorghum, Cotton. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Harper County a good location for home gardening?
Harper County scores 53/100 (Moderate) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. Conditions here are moderate — most common crops grow well with standard timing and care.
Your Harper County Garden Planner — Free
A 22-page printable planner built for Harper County (Zone 7a). 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