August is secretly one of the most important planting months in Pennsylvania — and most people miss it completely. While your tomatoes and peppers are pumping out fruit, the clock is already ticking on fall. If you want fresh greens, root vegetables, and brassicas this October and November, the seeds need to go in the ground now.
The fall growing season in PA is actually easier than spring in a lot of ways — fewer pests, cooler temps that greens love, and steady moisture. August planting is how you take advantage of all that.
What to Direct Sow in August
Count backward from your first fall frost. Every crop needs enough time to mature before freezing temps arrive.
| Zone | First Fall Frost | Days from Aug 1 |
|---|---|---|
| 7a (Philly) | November 17 | ~108 days |
| 6b (Reading, York) | Oct 19–22 | ~80–83 days |
| 6a (Pittsburgh) | Oct 10–28 | ~71–89 days |
| 5b (Scranton, Erie) | Oct 4–14 | ~65–75 days |
| 5a (Mountains) | Sept 28–Oct 1 | ~58–62 days |
Lettuce
Lettuce performs better in fall than spring in PA because cooling temps prevent bolting. Direct sow ¼ inch deep in rows 8–12 inches apart. Lettuce germinates poorly in hot soil (above 80°F) — sow in the evening and cover the row with a board for 2–3 days to keep soil cool.
Spinach
Fall is actually the better spinach season in PA. Sow in mid-to-late August once the worst heat passes. Spinach handles hard frost and light freezes — it’ll keep producing past your first frost date with a row cover.
Kale
Kale handles hard frost and keeps producing into November in most of PA. Frost actually improves the flavor — cold stress converts starches to sugar, making post-frost kale sweeter. Direct sow early August for zones 5a–6a, anytime in August for zones 6b–7a.
Radishes
Fastest reward in the fall garden — 25–30 days from seed to harvest. Sow ½ inch deep, thin to 1 inch apart, and succession plant every 10 days through September.
Arugula
Arugula thrives in cooler fall temperatures and is cold-tolerant enough to keep producing after light frosts. Ready in 30–40 days. Scatter seed on prepared soil and press lightly.
Turnips
45–60 days to maturity, handles frost well, and gives you two harvests — the root and the greens. Sow ½ inch deep, thin to 4 inches apart.
Beets
August-sown beets mature in about 50–65 days — right around first frost for most PA zones. Beets that size up in cool weather develop more sweetness than summer-grown ones.
Cilantro
Fall cilantro stays leafy and productive well into October and November — completely unlike the spring version that bolts by June. Sow ½ inch deep in mid-to-late August.
What to Transplant in August
If you started fall brassica seeds indoors in July, August is when those transplants go outside.
Broccoli, Cauliflower, and Cabbage
Transplant in early-to-mid August for zones 6a–6b, or mid-to-late August for zone 7a. They need 60–85 days to mature and actually head up better in cool fall weather. Space broccoli and cauliflower 18 inches apart, cabbage 12–15 inches.
Brussels Sprouts
If you started Brussels sprouts indoors in June or July, transplant them now. They need 80–100 days and require frost to develop their best flavor. A zone 6a–7a fall crop in PA. Space 24 inches apart.
What NOT to Plant in August
- Tomatoes, peppers, eggplant — no time to mature before frost.
- Beans — tight timing. After August 15, don’t bother.
- Corn, squash, cucumbers, melons — way too late.
- Warm-season herbs like basil — focus on cilantro, parsley, and dill instead.
August Lawn Care
Late August through mid-September is the #1 best window for lawn work in Pennsylvania. If your lawn has bare patches or thin spots, now is the time to overseed. Grass seed needs soil temps of 50–65°F to germinate well — that window happens naturally in late August and September.
If you’re going to aerate and overseed, do the aeration first, then overseed into the aeration holes. The combination is dramatically more effective than either approach alone. For more detail: When to Overseed in Pennsylvania.
August in the Fruit Garden
August is harvest month for many fruits. Blackberries ripen in July–August. Elderberries start ripening in August in warmer PA zones. Peaches, if you grow them, are at peak. For berry shrubs planted this year, focus on watering rather than fertilizing — late-summer fertilizing encourages vegetative growth that may not harden off before frost.
August Planting Calendar at a Glance
| Crop | Zone 5a–5b deadline | Zone 6a–6b deadline | Zone 7a deadline |
|---|---|---|---|
| Lettuce | Aug 1–10 | Aug 10–20 | Sept 1 |
| Spinach | Aug 15 | Aug 20 | Sept 10 |
| Kale | Aug 1–10 | Aug 15 | Sept 1 |
| Radishes | Aug 20 | Sept 1 | Sept 15 |
| Arugula | Aug 20 | Sept 1 | Sept 15 |
| Beets | Aug 1–10 | Aug 15 | Sept 1 |
| Turnips | Aug 1–10 | Aug 15 | Sept 1 |
| Cilantro | Aug 20 | Sept 1 | Sept 15 |
| Broccoli transplants | Aug 1–8 | Aug 1–15 | Aug 15–30 |
| Cabbage transplants | Aug 1–8 | Aug 1–15 | Aug 15–30 |
Frequently Asked Questions
Is it too late to plant vegetables in August in Pennsylvania?
Not at all — August is actually one of the best months for planting cool-season vegetables like lettuce, spinach, kale, radishes, and arugula. The key is choosing crops that can mature before your first fall frost. For most of PA, you have 60–100 days of growing season left from August 1, which is plenty for most greens and root vegetables.
What vegetables can I plant in August in Pennsylvania?
Great August crops for PA include lettuce, spinach, kale, arugula, radishes, beets, turnips, cilantro, and (early August) broccoli and cabbage transplants. Avoid warm-season crops like tomatoes, peppers, and cucumbers — they won’t have time to mature.
Can I plant garlic in August in Pennsylvania?
No — garlic is planted in October in Pennsylvania, not August. Garlic needs to go in the ground 4–6 weeks before hard frost so it can develop roots before winter, then sends up shoots in spring. August planting would result in too much top growth before winter, which is easily damaged. Wait until mid-to-late October.
Related Pennsylvania Planting Guides
Pennsylvania Frost Dates by Region · Complete PA Planting Guide by Season
