What to Plant in Santa Cruz & the Bay Area in August

August in Santa Cruz County is still hot, often as hot as July, but with a critical difference: days are noticeably shorter. This combination of heat plus shorter days makes August the absolute last good chance to plant most fall and winter crops.

Summer harvests are still abundant, but smart gardeners are filling beds with brassicas and greens that will feed them through winter.

Why August Is Your Deadline

August temperatures are still high:

Sunny mountain areas (Boulder Creek ridges, Ben Lomond chaparral, Scotts Valley hills): Still 85 to 100 degrees many days.

Under redwoods (Felton canyons, shaded areas): 75 to 85 degrees.

Inland valleys (Scotts Valley, Soquel): 80 to 90 degrees.

Coastal (Aptos, Capitola, Santa Cruz): 70 to 80 degrees.

Watsonville and Pajaro Valley: 80 to 90 degrees.

But day length is shrinking fast. Crops planted in August have enough time to establish before shorter fall days slow growth. Wait until September for many crops, and they won't size up properly.

Direct Seed These in August

Fall and Winter Greens

Lettuce: All varieties work in August. Germination is easier than July's heat. Choose heat-tolerant varieties for early August (Jericho, Nevada, Muir) and any variety for late August.

Arugula: Fast-germinating and reliable. Plant every two weeks for continuous harvest. Will bolt faster in early August heat but still produces well.

Spinach: Bloomsdale Long Standing handles warmth better than most. Late August plantings are more successful than early August.

Mustard greens: Red Giant and Green Wave establish quickly. More heat-tolerant than most greens.

Chard: Bright Lights and Fordhook Giant tolerate August warmth well. One of the most forgiving greens for summer planting.

Mizuna: Mild Japanese green that handles warmth reasonably well. Quick to produce.

Mâche (corn salad): Late August is ideal. This cool-weather specialist struggles in heat but thrives as temperatures moderate.

Asian greens: Bok choy, tatsoi, and pac choi for fall harvest. Late August plantings avoid the worst heat stress.

Root Vegetables

Beets: Detroit Dark Red and Chioggia establish well in August. Last call for full-size winter beets. Keep soil consistently moist for germination.

Carrots: Last call for full-size winter carrots. Nantes and Danvers types are reliable. August-planted carrots are sweetest after fall frosts. Consistent moisture is critical.

Radishes: Quick 30-day varieties give fast results while you wait for slower crops. Cherry Belle and Watermelon radish for variety.

Turnips: Hakurei and Tokyo Cross are mild and sweet. Fast-maturing for fall harvest.

Legumes

Peas: Late August for fall and winter harvest. Sugar snap and snow peas planted now establish over fall and produce through winter and into spring. Choose heat-tolerant varieties like Sugar Ann for early August.

Fava beans: Late August in coastal areas. Inland gardeners should wait until September. These nitrogen-fixers also make excellent cover crops.

Herbs

Cilantro: Excellent timing as temperatures moderate. Direct seed for fall harvest when it won't bolt immediately.

Dill: Quick to germinate and produce. Let some go to seed for self-sowing.

Parsley: Both flat-leaf and curly establish well. Slow to germinate (2 to 3 weeks), so be patient.

Cover Crops

If you have empty beds, plant cover crops in August:

Fava beans: Fix nitrogen and produce edible beans. The best all-around cover crop for our area.

Crimson clover: Beautiful red flowers in spring, fixes nitrogen, attracts pollinators.

Winter vetch: Good nitrogen fixer, combines well with other cover crops.

Transplant These in August

Fall and Winter Brassicas (from June and July Starts)

August is THE month for transplanting brassicas. If you started them in June or July, they need to go in the ground now.

Broccoli: Transplant by mid-August for fall harvest. Needs warm days to develop heads. De Cicco and Calabrese are reliable.

Cauliflower: Same timing as broccoli. Snow Crown and Amazing are good choices. More finicky than broccoli about timing.

Cabbage: More forgiving than broccoli. Can transplant through late August. Copenhagen Market and Savoy types do well.

Kale: Transplant all month. Lacinato (Dinosaur) and Red Russian are excellent. Extremely forgiving of timing.

Collards: Heat-tolerant and forgiving. Transplant anytime in August. Champion and Vates are reliable.

Brussels sprouts: Need the longest season. Early August transplanting is important for fall and winter harvest.

Kohlrabi: Quick-maturing brassica. Purple Vienna and White Vienna mature in 50 to 60 days.

Other Transplants

Lettuce: If you started seeds indoors to avoid heat, transplant now with afternoon shade protection.

Onions: From sets for spring and early summer harvest. They'll develop roots over fall and winter.

Start Seeds Indoors in August

For later transplanting:

Lettuce: Start indoors for September and October transplanting. Easier to germinate in controlled conditions.

More brassicas: For continuous harvests and to replace any that fail.

What to Harvest in August

Still peak summer. Don't let fall planting distract you from the abundance:

Tomatoes: Absolute peak in most areas. This is what you've been waiting for all year.

Peppers: Hot and sweet peppers are producing heavily. Harvest regularly to encourage more fruit.

Eggplant: Peak production in warm microclimates.

Cucumbers: Still producing if you've managed powdery mildew.

Summer squash and zucchini: Ongoing harvest. You probably have more than you need.

Beans: Bush and pole beans in full production.

Basil: Harvest heavily before it bolts in cooler fall weather.

Melons: Late varieties ripening now.

Early winter squash: Some varieties maturing.

Stone fruits: Peaches, plums, and nectarines finishing.

August Garden Tasks

Transplant all fall brassicas. This is the most important task of August. If you only do one thing, do this.

Direct seed greens, root vegetables, and peas for fall and winter harvest.

Continue harvesting summer crops heavily. Peak tomato season deserves your attention.

Pull spent crops only. If it's producing, leave it. Only remove plants that are truly done or diseased.

Add compost to beds before fall planting. Work in 2 to 3 inches of compost.

Plant cover crops in empty beds. Don't leave soil bare.

Water deeply. Still hot and dry. August is not the time to reduce irrigation.

Monitor for pests. Caterpillars LOVE brassicas. Check plants daily and hand-pick or use Bt.

Save seeds from heirloom tomatoes and peppers for next year.

Mulch new plantings heavily to keep soil cool and retain moisture.

Order garlic for October planting. Popular varieties sell out early.

Microclimate-Specific Advice for August

Coastal (Aptos, Capitola, Santa Cruz, Live Oak)

70 to 80 degrees, ideal for August planting. Your cooler temperatures and marine layer make this the easiest zone for establishing fall crops. Plant everything on this list without shade protection. Summer crops are still producing well but may slow down sooner than inland areas. This is the best microclimate for August brassica transplanting.

San Lorenzo Valley Sunny Ridges (Boulder Creek, Ben Lomond, Scotts Valley Hills)

Still 85 to 100 degrees on hot days. Summer crops are thriving, and tomatoes are at absolute peak. For fall plantings, provide afternoon shade for the first week or two, or plant late in the month when temperatures start moderating. Your warm microclimate means summer crops will continue producing into October. You can continue planting cool-season crops through September and even into October.

San Lorenzo Valley Shaded Areas (Felton, Ben Lomond Canyons)

75 to 85 degrees, excellent for fall planting. Your shade is a huge advantage now. Brassicas and greens will establish beautifully without extra protection. Just ensure you have enough light (4 to 6 hours minimum) for proper growth. This is often the easiest microclimate for August planting after coastal areas.

Inland Valleys (Scotts Valley, Soquel Hills)

80 to 90 degrees. Good for fall planting, though early August may need shade for transplants. Late August is ideal timing. Summer crops still producing well.

Watsonville and Pajaro Valley

80 to 90 degrees, warm agricultural zone. Plant everything on this list. Your extended season means summer crops will continue well into fall, and fall crops have a long, mild growing season ahead. August is perfect for fall plantings that will mature in your mild winter.

The August Overlap Strategy

August is THE overlap month. You're operating in two seasons simultaneously:

Still summer: Peak harvests of tomatoes, peppers, and squash. Hot temperatures. Regular watering needed. Summer crops producing heavily.

Becoming fall: Shorter days. Planting cool-season crops. Preparing for eventual rain. Planning winter garden.

Master this overlap and you'll never have a gap in harvests. The key is accepting that you're maintaining two gardens at once: harvesting one while establishing another.

Succession Planting in August

Don't plant everything at once. Stagger plantings 2 to 3 weeks apart:

Lettuce: Plant every 2 weeks for continuous salad greens through fall and winter.

Arugula: Plant every 2 weeks. Fast-growing, so regular succession is essential.

Radishes: Plant every 2 weeks for continuous harvest.

Beets and carrots: Plant 2 to 3 batches in August for staggered fall and winter harvest.

This gives you continuous harvests instead of a glut followed by nothing.

August Deadlines: What Must Be Planted Now

For many crops, August is the deadline:

Must plant in August:

• Broccoli and cauliflower (for proper heading before short days)

• Full-size carrots and beets (for winter harvest)

• Peas (for winter and spring harvest)

• Brussels sprouts (need longest season)

Can wait until September:

• Quick greens (lettuce, arugula, spinach)

• Radishes

• Kale and collards

But even crops that CAN wait until September will do better if planted in August. The extra growth time makes a real difference.

Local Resources for August Gardening

Transplants and Seeds

Sierra Azul Nursery (2660 E. Lake Avenue, Watsonville) has fall vegetable transplants including brassicas and greens.

San Lorenzo Garden Center (808 River Street, Santa Cruz) stocks brassica transplants and fall vegetable seeds.

Scarborough Gardens (33 El Pueblo Road, Scotts Valley) carries fall vegetable starts.

Mountain Feed & Farm Supply (9550 Highway 9, Ben Lomond) has cover crop seeds and fall planting supplies.

Seeds by Mail

Renee's Garden Seeds (based in Felton) carries heat-tolerant lettuce varieties and fall vegetable seeds suited to our climate.

Peaceful Valley Farm Supply (ships to Santa Cruz) has excellent selection of cover crop seeds and fall vegetables.

Education

UC Master Gardeners of Monterey Bay offer fall planting workshops and can answer questions about the summer-to-fall transition.

Frequently Asked Questions About August Gardening

Is it too late to plant tomatoes?

Yes, for fruit production. Even fast-maturing varieties planted in August won't have time to ripen fruit before October and November weather slows them down. Focus your energy on fall crops. Your existing tomatoes will continue producing for weeks.

Can I harvest summer crops AND plant fall crops at the same time?

Absolutely. August is the peak overlap month. You're simultaneously harvesting tomatoes, peppers, and squash while transplanting brassicas and seeding greens. This dual-season approach is normal and expected. You're maintaining two gardens at once.

When will my August plantings be ready?

Quick greens and radishes: October (30 to 50 days). Brassicas: November through January (60 to 90 days). Carrots and beets: October through November (60 to 75 days). Peas: December through February (70 to 90 days).

Should I pull tomatoes to make room for fall crops?

Only if they're diseased or truly done producing. In warm microclimates (sunny mountains, Watsonville), August tomatoes will produce through September and into October. If they're healthy and still flowering, leave them. Find other space for fall crops.

Why are my lettuce seedlings bolting?

August can still be hot. Choose bolt-resistant varieties for early August (Jericho, Nevada, Muir), or wait until late August when temperatures moderate. Pre-sprouting seeds indoors before planting in cooler conditions helps avoid heat stress.

Is it too late to start brassicas from seed?

For most brassicas, yes. August transplants need to have been started in June or July. If you haven't started them, buy transplants from local nurseries. The exception is kale and collards, which are forgiving enough to start from seed in August and still produce well.

How do I protect August transplants from heat?

Provide afternoon shade for the first week or two using shade cloth, a board propped up on the west side, or even a patio umbrella. Water deeply and mulch heavily. Transplant in the evening rather than morning. Late August plantings need less protection as temperatures moderate.

What if I missed August planting entirely?

You can still plant quick greens (lettuce, arugula, spinach, radishes) and kale and collards in September. But broccoli, cauliflower, full-size carrots and beets, and Brussels sprouts really need August planting to mature properly. Consider focusing on what's still possible rather than what you missed.

Free Gardening Resources

Seasonal Planting Calendar — Month-by-month planting guide for Santa Cruz County, including August's critical deadlines.

Vegetables by Season — Quick reference for which vegetables to plant in the summer-to-fall transition.

Know Your Microclimate Worksheet — Identify your specific growing conditions to understand August temperatures in your location.

Seasonal Tasks Checklist — August tasks alongside year-round garden maintenance.

The Most Important Planting Month

August is the most important planting month of the year for fall and winter food. Skip it, and you'll have very few options through winter.

The work you do in August, transplanting brassicas, seeding greens, succession planting, determines what you'll eat from November through March. Don't let summer abundance make you complacent about fall preparation.

Your future self will thank you for every brassica transplanted, every row of carrots seeded, every succession of lettuce planted. This is the month that feeds you through winter.