Is It Too Late to Plant Seeds? What You Can Still Plant in Late August and September
If you're standing in your garden in late August wondering whether the growing season has passed you by — it hasn't. There's still a surprisingly long list of seeds you can plant right now, and some of the best cool-season crops and flowers actually prefer the cooler temperatures that September brings. This guide breaks it all down by plant type so you can make the most of what's left of the season.
Why Late August and September Are Actually Great for Planting
The secret most gardeners don't realize: many plants actively dislike summer heat. Lettuce bolts, pansies sulk, and kale turns bitter when temperatures climb. But as August winds down and September arrives, the soil is still warm enough to germinate seeds quickly — while the air cools to the sweet spot that cool-season crops love. You get fast germination and ideal growing conditions. That's a win.
The key is knowing your first frost date and counting backward. Most cool-season crops need 45–70 days to maturity. If your first frost is in late October or November, you have a full growing window right now.
🌿 Cool-Season Vegetables to Plant Now
Lettuce
Lettuce is one of the fastest and most rewarding fall crops. It germinates in warm soil, grows quickly in cool air, and tastes sweeter after a light frost. Direct-sow or start indoors and transplant in 2–3 weeks.
Crisphead Hanson Improved Lettuce Seeds — 3,000 Seeds — a reliable, heat-tolerant variety that transitions beautifully into fall.
Spinach & Orach
Orach (mountain spinach) is a heat-tolerant spinach alternative that thrives in the transition from summer to fall. It's stunning in the garden and delicious in salads.
Purple Orach Mountain Spinach Seeds — 500 Seeds — gorgeous purple foliage, edible, and incredibly easy to grow.
Beans (Zones 7–10)
If you're in a mild climate, fast-maturing bush beans can still produce a full harvest before frost. Aim for varieties that mature in 50–60 days and direct-sow now.
🌸 Cool-Season Flowers to Start Now
Ornamental Kale & Flowering Cabbage
This is the perfect time to start ornamental kale from seed. Started now, they'll be ready to transplant into fall containers and garden beds in 6–8 weeks — just as the season calls for rich color. They look stunning through frost and into early winter.
Browse our full Ornamental Kale & Flowering Cabbage collection for more varieties.
Pansies — The Ultimate Fall Flower
Pansies started from seed in late August will be blooming by October and can carry color all the way through winter in mild climates. The Cool Wave® trailing series is especially spectacular in hanging baskets and window boxes.
Sunflowers (Zones 7–10, Direct Sow)
In warmer zones, fast-maturing and branching sunflowers can still be direct-sown in late August. The Sunfinity series is a standout — it branches continuously and blooms for months rather than weeks.
🌺 Start Lisianthus Now for Next Summer's Blooms
Here's a pro tip that most gardeners miss: late August through October is the ideal window to start lisianthus seeds indoors for blooms next summer. Lisianthus has a long growing period — typically 5–6 months from seed to first bloom — so starting now puts you perfectly on track for stunning cut flowers next June and July.
These are not beginner seeds, but they are absolutely worth the effort. Pelleted seeds make germination much more manageable.
Browse our full Lisianthus Seeds collection for all available varieties.
Quick Reference: What to Plant by Zone in Late August–September
| Zone | What to Plant Now |
|---|---|
| Zones 4–6 | Start pansies, ornamental kale, and lisianthus indoors. Direct-sow spinach and lettuce for a quick harvest before frost. |
| Zones 7–8 | Direct-sow lettuce, spinach, kale, beans, and fast sunflowers. Start pansies and ornamental kale indoors for fall transplanting. |
| Zones 9–10 | Full fall garden season begins now. Plant cool-season vegetables, flowers, and start lisianthus indoors for next summer. |
❓ Frequently Asked Questions
Is it too late to plant seeds in late August?
No! Late August is still a great time to start cool-season vegetables like lettuce, spinach, kale, and ornamental kale, as well as flowers like pansies, alyssum, and nemesia. In warmer zones (7–10), you can also direct-sow fast-maturing beans and sunflowers.
What vegetables can I plant from seed in September?
In September you can plant lettuce, spinach, orach, kale, ornamental kale, radishes, and beets from seed. In mild climates (zones 8–10), you can also start cool-season greens that will mature before hard frost.
Can I still plant sunflowers in late August?
Yes, in zones 7–10 you can direct-sow fast-maturing sunflower varieties in late August and still get blooms before frost. Dwarf and branching types like Sunfinity are especially good choices since they bloom continuously.
What flowers can I start from seed in late August or September?
Pansies, alyssum, nemesia, ornamental kale, and flowering cabbage are all excellent choices for late August and September seed starting. These cool-season flowers thrive in fall temperatures and can handle light frost.
When should I start lisianthus seeds for next year?
Lisianthus seeds should be started indoors in late August through October for blooms the following summer. They have a long growing period (5–6 months from seed to bloom), so starting now gives them a head start for next season.
Can I plant beans in late August?
In zones 7–10, yes. Fast-maturing bush beans like Blue Lake and Slenderette can be direct-sown in late August and will produce a harvest before the first hard frost. Aim for varieties that mature in 50–60 days.
More Planting Guides You'll Love
- What to Plant in September by USDA Zone: Complete Fall Garden Guide
- What to Plant in August: Best Flowers & Seeds for Late Summer Gardens
- What Seeds to Plant in October and December: Lisianthus, Anemone, Ranunculus & More
- Flowering Kale: Complete Guide to Growing Ornamental Kale from Seed
- Is It Too Late to Plant Beans in July and August in Zone 8?
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