Chrysanthemums — garden mums — are the classic autumn flower of a Zone 7 garden, opening in a blaze of gold, rust, pink and white just as the summer flowers fade. They are the plant that makes an October garden look deliberate rather than finished. In Zone 7, hardy garden mums planted in spring will come back year after year; the potted florist mums sold in autumn are often less hardy and are best treated as seasonal colour. Plant mums in spring, pinch them through early summer to keep them bushy, and they will reward you with a dense mound of flowers in autumn — and with luck, for many autumns to come.
Zone 7 at a glance
USDA Zone 7 has average winter lows of 0 to 10°F, and the frost-free season runs from Mar 15–Apr 1 to Nov 1–15 in an average year — roughly seven to eight frost-free months. Those are USDA/NOAA zone averages, not promises for any one garden — check your local extension service for your own frost dates, because microclimate, elevation and the year itself can shift them by weeks. The planting calendar hub gives the Zone 7 picture month by month, and the frost date calculator can help you work from your own local averages.
| Detail | Zone 7 guidance |
|---|---|
| Average last spring frost | Mar 15–Apr 1 (average/range) |
| Average first autumn frost | Nov 1–15 (average/range) |
| Winter low | 0 to 10°F |
| Days to germination | 7–14 days |
| Days to maturity | 90–120 days |
| Sowing | both |
| Transplanting | After Mar 15–Apr 1 (spring planting) |
| Harvest | Flowers in autumn, 90–120 days |
| Sun | full sun |
| Soil pH | 6.0–7.0 |
| Spacing | 12–18 inches |
| Water needs | moderate |
When to plant chrysanthemums in Zone 7
Chrysanthemums are hardy in Zone 7, so plant in spring after the last frost (Mar 15–Apr 1) — spring planting is what makes them reliably perennial, because the plant has a whole season to establish roots before winter. Autumn-planted mums often fail to survive their first winter, which is why the spring rule matters. The first frost (Nov 1–15) ends the flowering season.
Seed germinates in 7–14 days in warm, moist soil. Give seedlings strong light and harden them off for a week before they go outside. The seed-starting calculator turns your frost averages into sowing dates — see also Zone 7 April for what else is happening in the garden that month.
Starting chrysanthemums in Zone 7
Chrysanthemums can be started indoors or sown direct, but most Zone 7 gardeners buy young plants in spring — that gives them a full season to establish before they flower in autumn. Sow seed indoors six to eight weeks before the last frost, or direct after it; germination takes 7–14 days. Plant out after the last frost (Mar 15–Apr 1), spacing plants 12–18 inches apart in full sun and rich soil. Pinch out the growing tips every few weeks until midsummer to encourage branching — stop pinching by midsummer, or you will remove the buds that make the autumn flowers.
Soil, spacing, sun and water
Chrysanthemums grow best in full sun, in soil with a pH of 6.0–7.0. Dig in well-rotted compost before planting to improve drainage and moisture holding. Space plants 12–18 inches apart — it is tempting to crowd plants in, but crowded plants stay small and invite disease, so use the plant spacing calculator if you are laying out a bed. Chrysanthemums need moderate water: Water deeply and less often rather than lightly every day, water at the base in the morning so leaves dry before night, and mulch to keep the soil evenly moist.
Companion planting
Good companions for chrysanthemums include lavender, marigolds, garlic, chives. The companion planting finder can suggest combinations for your whole bed. Avoid planting chrysanthemums where the same family (Asteraceae) grew last year, and keep aggressive spreaders in their own space so they do not crowd out slower neighbours. For a bed that works well together, see Zone 7 Marigolds.
Pests and problems
The common pests and problems to watch for with chrysanthemums are aphids, slugs, thrips. Aphids cluster on soft new growth and buds; wash them off with a strong jet of water and encourage ladybirds. Slugs and snails chew seedlings and low leaves at night, especially in damp weather; go out after dark with a torch, or use barriers and traps. Thrips rasp the surface of leaves and petals, leaving silvery marks; remove badly affected flowers and keep plants unstressed. Inspect plants regularly and act early — healthy, well-spaced plants resist pests better than stressed ones.
Harvest and storage
Chrysanthemums take 90–120 days to maturity, flowering in autumn. Cut stems in the morning when the flowers are fully open, and put them straight into water. Deadhead spent blooms to keep the display tidy. After flowering, leave the stems standing over winter — they protect the crown from frost — and cut them back in spring when new growth appears. In Zone 7, hardy garden mums usually survive winter with a mulch over the crown; in a cold snap, extra mulch helps. Divide congested clumps in spring every two or three years.
Frequently asked questions
When should I plant chrysanthemums in Zone 7?
Work from the frost averages: last frost Mar 15–Apr 1, first frost Nov 1–15. Chrysanthemums are hardy in Zone 7, so time your sowing and planting around those dates rather than a calendar date, and check your local extension service for your own frost dates.
Can I grow chrysanthemums in Zone 7?
Yes, with the right timing and variety choice. Chrysanthemums are hardy and need 90–120 days to maturity, so choose a variety that fits the Zone 7 season.
How far apart should I space chrysanthemums in Zone 7?
Space plants 12–18 inches apart, in full sun and soil with a pH of 6.0–7.0. Crowding slows growth and invites disease, which matters more in a season with limited frost-free days.
What pests affect chrysanthemums in Zone 7?
The most common are aphids, slugs, thrips. Inspect leaves regularly and act early; healthy, well-spaced plants resist pests better than stressed ones.
How do I know when chrysanthemums are ready to harvest?
Allow 90–120 days to maturity from sowing or transplanting, and harvest at the stage for your variety. Pick in the morning when plants are cool, and harvest everything usable before the first autumn frost, which averages Nov 1–15 in Zone 7.