Oklahoma’s intense August heat requires selecting vegetables bred to withstand drought and high temperatures. If you’re searching for the best vegetables to plant in august in oklahoma, you need crops that thrive when the thermometer hits triple digits. August planting here is all about quick-maturing varieties and heat-tolerant selections that can handle the unique challenges of late-summer gardening in the Sooner State.
Many gardeners think August is too late to start a vegetable garden. That’s not true in Oklahoma. With the right choices, you can harvest fresh produce well into fall. The key is picking vegetables that germinate fast in hot soil and mature before the first frost.
Let’s get straight to what works. This guide covers the top vegetables for August planting in Oklahoma, plus tips for keeping them alive when the sun is brutal.
Best Vegetables To Plant In August In Oklahoma
Warm-Season Vegetables That Love The Heat
Some vegetables actually prefer hot weather for germination and early growth. These are your best bets for August planting.
Southern Peas (Cowpeas)
Southern peas are practically bulletproof in Oklahoma heat. They laugh at 100-degree days and poor soil. Plant them directly in the ground from early to mid-August.
- Varieties: Blackeye, Purple Hull, Cream 40
- Days to maturity: 60-70 days
- Planting depth: 1 inch
- Spacing: 2-4 inches apart in rows 3 feet apart
These peas fix nitrogen in the soil, which helps later crops. They need minimal water once established. Harvest when pods are plump but before they turn yellow.
Okra
Okra thrives in Oklahoma’s August heat. It actually produces better when temperatures stay above 85°F. Plant seeds directly in warm soil.
- Varieties: Clemson Spineless, Emerald, Burgundy
- Days to maturity: 50-60 days
- Planting depth: 1/2 to 1 inch
- Spacing: 12-18 inches apart
Soak seeds overnight before planting to speed germination. Okra pods get tough quickly, so harvest every 2-3 days when pods are 2-3 inches long.
Summer Squash And Zucchini
These fast-growing vegetables can still produce a good harvest if planted by mid-August. Choose bush varieties for quicker results.
- Varieties: Yellow Crookneck, Straightneck, Black Beauty zucchini
- Days to maturity: 45-55 days
- Planting depth: 1 inch
- Spacing: 24-36 inches apart
Squash vine borers are less active in late summer, so August planting often avoids this pest. Water at the base to prevent powdery mildew. Harvest when fruits are 6-8 inches long.
Sweet Corn
Yes, you can still plant sweet corn in August in Oklahoma. Choose early-maturing varieties that need only 60-70 days.
- Varieties: Early Sunglow, Golden Bantam, Honey Select
- Days to maturity: 60-75 days
- Planting depth: 1-2 inches
- Spacing: 8-12 inches apart in blocks for pollination
Plant corn in blocks of at least 4 rows for good pollination. Keep soil consistently moist until germination. Expect harvest around mid-October if you plant in early August.
Cool-Season Vegetables For Fall Harvest
August is the perfect time to start cool-season crops for fall eating. These vegetables germinate in warm soil but mature as temperatures cool down.
Beans (Bush And Pole)
Beans grow quickly and tolerate August heat if you keep them watered. Bush beans are faster, but pole beans produce longer.
- Varieties: Provider, Blue Lake, Contender
- Days to maturity: 50-60 days
- Planting depth: 1-1.5 inches
- Spacing: 2-4 inches apart
Plant beans every 2 weeks until mid-August for continuous harvest. They need about 1 inch of water per week. Pick pods when they’re young and tender.
Cucumbers
Cucumbers love warm soil for germination. August planting gives you a late-summer crop before frost.
- Varieties: Marketmore, Straight Eight, Bush Pickle
- Days to maturity: 50-65 days
- Planting depth: 1/2 inch
- Spacing: 12-18 inches apart
Use trellises to save space and improve air circulation. Harvest cucumbers when they’re 6-8 inches long for slicers, or 2-4 inches for pickles. Bitter cucumbers mean they got too much heat stress.
Pumpkins
For Halloween pumpkins, plant by mid-August in Oklahoma. Choose small to medium varieties that mature in 90-100 days.
- Varieties: Jack Be Little, Small Sugar, Howden
- Days to maturity: 90-110 days
- Planting depth: 1 inch
- Spacing: 3-4 feet apart
Pumpkins need lots of water during fruit development. Watch for powdery mildew in late summer. Harvest when the rind is hard and the stem starts to crack.
Radishes
Radishes are the fastest vegetable you can plant in August. Some varieties are ready in just 25 days.
- Varieties: Cherry Belle, French Breakfast, White Icicle
- Days to maturity: 25-30 days
- Planting depth: 1/2 inch
- Spacing: 1 inch apart
Sow radish seeds every 2 weeks for continuous harvest. They need consistent moisture to stay tender. Hot weather makes radishes spicy, so harvest promptly.
Turnips And Rutabagas
These root vegetables do well when planted in August for fall harvest. The cooler autumn weather sweetens their flavor.
- Varieties: Purple Top White Globe, Golden Ball, Laurentian
- Days to maturity: 50-70 days
- Planting depth: 1/2 inch
- Spacing: 2-4 inches apart
Thin seedlings to prevent crowding. Turnip greens are edible too. Harvest roots when they’re 2-3 inches in diameter for best flavor.
Carrots
Carrots need consistent moisture to germinate, which can be tricky in August heat. But fall carrots are sweeter than spring ones.
- Varieties: Danvers, Nantes, Scarlet Nantes
- Days to maturity: 60-75 days
- Planting depth: 1/4 inch
- Spacing: 1-2 inches apart after thinning
Keep soil moist until seeds germinate, which can take 2-3 weeks in hot weather. Cover seeds with vermiculite or shade cloth to prevent drying out. Harvest after a light frost for sweeter flavor.
Beets
Beets handle heat better than carrots. They germinate quickly and produce both roots and greens.
- Varieties: Detroit Dark Red, Golden, Chioggia
- Days to maturity: 50-60 days
- Planting depth: 1/2 inch
- Spacing: 2-3 inches apart
Soak seeds overnight to speed germination. Beets need consistent moisture for tender roots. Harvest when roots are 1.5-2 inches in diameter.
Kale And Collards
These leafy greens actually taste better after a frost. August planting gives them time to establish before cool weather.
- Varieties: Lacinato, Red Russian, Vates
- Days to maturity: 50-70 days
- Planting depth: 1/4 inch
- Spacing: 12-18 inches apart
Kale and collards tolerate heat better than lettuce. Harvest outer leaves when they’re 8-10 inches long. Plants will produce through fall and even into winter with protection.
Swiss Chard
Swiss chard is heat-tolerant and productive. It’s a great alternative to spinach, which struggles in Oklahoma heat.
- Varieties: Bright Lights, Fordhook Giant, Ruby Red
- Days to maturity: 50-60 days
- Planting depth: 1/2 inch
- Spacing: 8-12 inches apart
Harvest outer leaves when plants are 8-10 inches tall. Chard will produce until a hard freeze. The colorful stems add beauty to the garden.
Leafy Greens For Late Summer
Some greens handle August heat better than others. These are your best options for salads and cooking greens.
Lettuce (Heat-Tolerant Varieties)
Standard lettuce bolts quickly in heat. Choose heat-tolerant varieties for August planting.
- Varieties: Buttercrunch, Red Sails, Black Seeded Simpson
- Days to maturity: 45-60 days
- Planting depth: 1/8 inch
- Spacing: 6-12 inches apart
Plant lettuce in partial shade if possible. Use shade cloth to reduce heat stress. Harvest leaves individually for a longer harvest period.
Spinach (Malabar And New Zealand)
True spinach hates heat. But Malabar spinach and New Zealand spinach are heat-loving alternatives.
- Varieties: Malabar Red Stem, New Zealand
- Days to maturity: 60-70 days
- Planting depth: 1/2 inch
- Spacing: 12-18 inches apart
These aren’t true spinach but taste similar. They thrive in Oklahoma’s August heat. Harvest tender tips and leaves regularly to encourage growth.
Arugula
Arugula grows fast and adds peppery flavor to salads. It tolerates heat better than lettuce.
- Varieties: Rocket, Astro, Sylvetta
- Days to maturity: 20-40 days
- Planting depth: 1/4 inch
- Spacing: 1 inch apart
Sow arugula every 2 weeks for continuous harvest. It gets spicier in hot weather. Harvest leaves when they’re 2-3 inches long.
Mustard Greens
Mustard greens are heat-tolerant and quick-growing. They add zesty flavor to salads and stir-fries.
- Varieties: Southern Giant Curled, Red Giant, Mizuna
- Days to maturity: 30-45 days
- Planting depth: 1/4 inch
- Spacing: 4-6 inches apart
Harvest outer leaves when plants are 6-8 inches tall. Mustard greens tolerate light frost. They’re ready to eat in just 3-4 weeks.
Tips For Successful August Planting In Oklahoma
Soil Preparation
August soil in Oklahoma is often hard and dry. Prepare it properly for good germination.
- Water the soil deeply 2-3 days before planting
- Add 2-3 inches of compost or aged manure
- Work the soil to a depth of 6-8 inches
- Rake smooth and remove rocks and clods
Good soil preparation helps seeds germinate faster and roots grow deeper. This is critical in hot weather.
Watering Strategies
Water is the most important factor for August planting. Here’s how to do it right.
- Water deeply in the morning, not evening
- Use drip irrigation or soaker hoses to avoid wetting leaves
- Water 1-2 inches per week, more during heat waves
- Mulch around plants with 2-3 inches of straw or wood chips
Consistent moisture prevents blossom-end rot in tomatoes and squash. It also keeps roots cool in hot soil.
Shade And Protection
Young seedlings need protection from intense August sun. Use these methods.
- Install shade cloth (30-50% shade) over new plantings
- Plant taller crops like corn or okra on the west side to shade smaller plants
- Use row covers to reduce heat stress
- Plant in areas that get afternoon shade
Shade cloth can reduce soil temperature by 10-15°F. Remove it after plants are established, usually 2-3 weeks.
Timing Your Planting
August planting in Oklahoma requires careful timing. Here’s a schedule.
- Early August (1st-10th): Southern peas, okra, sweet corn, pumpkins, cucumbers
- Mid-August (11th-20th): Beans, squash, carrots, beets, turnips
- Late August (21st-31st): Kale, collards, lettuce, radishes, arugula
Check your first frost date for your area. In northern Oklahoma, it’s usually mid-October. In southern Oklahoma, it’s late October to early November.
Pest Management
August brings specific pests. Here’s what to watch for.
- Aphids: Spray with insecticidal soap or strong water stream
- Squash bugs: Hand-pick eggs and adults, use neem oil
- Cucumber beetles: Use row covers until flowering
- Tomato hornworms: Hand-pick or use Bt (Bacillus thuringiensis)
Healthy plants resist pests better. Keep your garden clean and remove diseased plants quickly.
Fertilizing Your August Garden
August soil often lacks nutrients after spring crops. Feed your vegetables properly.
- Use a balanced fertilizer (10-10-10) at planting time
- Side-dress with compost tea or fish emulsion every 3-4 weeks
- Avoid high-nitrogen fertilizers for root crops like carrots and beets
- Apply liquid fertilizer weekly for fast-growing crops like lettuce and radishes
Too much nitrogen makes leafy greens grow fast but reduces flavor. Follow package directions for application rates.
Common Mistakes To Avoid
Even experienced gardeners make errors in August. Here’s what to skip.
- Planting too deep: Seeds need to be shallow in hot soil
- Overwatering: Soggy soil causes root rot and fungal diseases
- Ignoring soil temperature: Use a soil thermometer to check if it’s below 85°F for cool-season crops
- Planting too late: Check days to maturity against your first frost date
- Skipping mulch: Bare soil loses moisture fast in August heat
Learn from these mistakes and your August garden will thrive.
Harvesting Your August-Planted Vegetables
Knowing when to harvest makes a big difference in flavor and quality.
- Okra: Harvest pods at 2-3 inches, every 2-3 days
- Southern peas: Pick when pods are plump but still green
- Summer squash: Harvest at 6-8 inches, before seeds develop
- Beans: Pick when pods are firm and snap easily
- Carrots: Harvest when tops are 1/2 to 3/4 inch in diameter
- Kale: Pick outer leaves when 8-10 inches long
Regular harvesting encourages more production. Don’t let vegetables over-mature on the plant.
Extending The Season Into Fall
Your August garden can produce well into November with some help.
- Use row covers or cold frames to protect from early frost
- Plant fast-maturing varieties that finish before hard freeze
- Mulch heavily around root crops to keep soil warm longer
- Harvest all tender vegetables before first frost in mid-October
Hardy vegetables like kale, collards, and turnips can survive light frosts. They actually taste sweeter after cold weather.