What to Plant in August (Zone 8a & 8b Pacific Northwest Guide)
August often feels like the garden is winding down, but in the Pacific Northwest it's really the start of the next growing season.
While tomatoes and beans continue producing, the cooler evenings create perfect conditions for sowing many vegetables that struggle during the heat of midsummer. A few minutes spent planting now can reward you with fresh harvests well into autumn—and, with a little protection, even through winter.
This guide is written for gardeners in the milder parts of the Pacific Northwest (primarily USDA Zones 8a and 8b, including much of western Washington and western Oregon). If you're gardening in colder inland areas, you may need to adjust these planting dates by a couple of weeks.
Vegetables to Plant
Plant | Sow or Transplant | Harvest |
|---|---|---|
Lettuce | Sow every 2 weeks | Sept–Oct |
Spinach | Sow late August | Autumn & winter |
Kale | Sow or transplant | Autumn onward |
Swiss Chard | Sow or transplant | Sept onwards |
Carrots | Direct sow | October |
Beets | Direct sow | October |
Radishes | Direct sow | 4–6 weeks |
Turnips | Direct sow | October |
Pak Choi | Direct sow | September |
Asian Greens | Direct sow | September |
Brassicas
August is also an excellent month to transplant:
Broccoli
Cauliflower
Cabbage
Brussels sprouts
Transplanting brassicas in August gives them time to establish before the cooler weather of autumn, often resulting in sweeter, more reliable harvests.
Herbs
Plant or sow:
Parsley
Cilantro
Dill
Chives
Parsley and cilantro often thrive in the cooler temperatures of late summer. Basil, on the other hand, prefers warm weather, so it's best left until next spring unless you're growing under protection.
Flowers
Plant now for autumn colour
Pansies
Violas
Calendula
Sweet Alyssum
Sow now for next spring
Forget-me-nots
Foxgloves
Wallflowers
If you're thinking ahead to spring, it's also a good time to order bulbs ready for autumn planting.
What Not to Plant in August
Generally avoid starting from seed:
Tomatoes
Peppers
Eggplant
Sweet corn
Pumpkins
Winter squash
Melons
These warm-season crops generally won't have enough time to mature before cooler autumn weather arrives in most Pacific Northwest gardens.
Five August Jobs
Continue watering deeply while the weather remains warm, adjusting as cooler nights and autumn rains begin to arrive.
Keep harvesting beans, cucumbers, and zucchini.
Deadhead flowering plants to encourage more blooms.
Refresh mulch if it has broken down over summer.
Start planning your autumn vegetable beds.
Quick Wins for August
If you only plant three things this month, make them:
🥬 Lettuce
🥕 Carrots
🌿 Spinach
These are among the easiest and most reliable crops to sow in August across the Pacific Northwest.
Related reads
A few more posts that pair well with this one.
Beginner Raised Bed Garden
→Learn how to build a simple raised bed garden in the Pacific Northwest. Includes wood vs metal beds, where to place them, what soil to use, and easy crops for beginners.
What to Buy at the Garden Center in Early Spring
→Not sure what to buy at the garden center this spring? These easy plants thrive in Pacific Northwest gardens and are perfect for beginners.
What to Plant in March in Washington State (PNW Gardening Guide)
→Wondering what to plant in March in Washington State? A practical Pacific Northwest gardening guide covering vegetables, flowers, herbs, and trees you can plant now — indoors and out.
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