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New England Cut Flower Planting Calendar
When to start, sow and plant the flowers we grow, counted back from a Lakes Region last frost, plus a month-by-month checklist.
Everything here counts back from your average last spring frost. Around Moultonborough that's usually the last week of May. Look up your own date and adjust, and remember that average means some years it's later.
Start, sow and plant
| Flower | Start indoors | Goes outside | Blooms |
|---|---|---|---|
| Snapdragon | 8–10 weeks before last frost | About 2 weeks before last frost (it likes cool weather) | Early summer |
| Strawflower | 6–8 weeks before | After last frost | Midsummer to frost |
| Celosia | 6–8 weeks before | 1–2 weeks after last frost, once nights stay warm | Midsummer to frost |
| Dahlia from seed | 6–8 weeks before | After last frost | Late summer |
| Amaranthus | 4–6 weeks before, or direct sow | After last frost | Midsummer to frost |
| Zinnia | 4 weeks before, or direct sow | After last frost, in warm soil | Midsummer to frost |
| Dahlia tubers | Optional: pot up in mid-April for a head start | After last frost, when soil reaches about 60°F | Midsummer to frost |
Month by month
- January–February: Order seed and tubers. Check stored tubers once a month. Plan your beds.
- March: Start snapdragons. Set up lights and seed trays.
- April: Start strawflower, celosia and dahlia seed early in the month; amaranthus later. Pot up dahlia tubers if you want early blooms.
- May: Start zinnias. Harden off seedlings for 7–10 days. Plant snapdragons out mid-month.
- Late May–June: After last frost, plant everything else and direct sow zinnias. Set dahlia stakes at planting time.
- July–August: Pinch, stake, water deeply and cut often. The more you cut, the more you get.
- September: Peak dahlia season. Watch for the first frost warning.
- October–November: Dig, divide and store dahlias. Save seed from your favorite open-pollinated plants.
Write your own frost dates in the margin. They're your most important numbers.
From Knollwood Flowers · Moultonborough, NH · knollwoodflowers.com
