Heirloom Chrysanthemum Care for Late Summer

Heirloom chrysanthemums are some of the most rewarding flowers to grow—those intricate, old-fashioned blooms feel like pieces of history in the garden. As summer begins to wind down, now is the time to switch from growth mode to bloom prep. The extra care you give them now will reward you with strong stems, healthy plants, and gorgeous fall blooms. Whether you’re growing in pots or in the field, these tips will help your mums thrive through the transition into autumn.

Pictured: French Vanilla an early blooming variety rich in a warm French Vanilla tone.

🌱 Growing & Feeding

• Keep your summer routine: Continue watering, feeding, and pest control until buds are visible and “taken” (more on that below).

• Water deeply and thoughtfully: Water thoroughly, then let the soil dry slightly before watering again. Water early in the morning or evening on hot days to avoid stress.

• Fertilizer adjustments:

  • While plants are actively growing, feed with a 20-10-20 fertilizer.

  • Once buds appear, reduce fertilizer to half strength for 2–3 weeks.

  • Switch to a fertilizer with higher potash content to harden plants and promote strong blooms.

📏 Staking & Bloom Support

• Stake heavily: Chrysanthemums can’t be over-supported. Tie laterals and main stems securely to keep them upright as blooms get heavy.

• “Taking the bud”: When buds reach pea size, remove the surrounding side buds and shoots below it so the plant focuses energy on one perfect bloom per stem.

🪴 Soil Care (For Pots or Beds)

• Reduce salt buildup: Flush containers if growing in pots by watering deeply and letting excess water drain to wash away accumulated salts.

• Top-dress for healthy roots: Add a light layer of compost or growing mix around the base of your plants to refresh nutrients and encourage strong root growth.

🐞 Pest & Disease Management

• Inspect regularly: Check for black aphids, earwigs, leaf rollers, and other pests. Neem oil is a great organic choice; Sevin or Marathon can help if pests are persistent.

• Disease prevention: Spray fungicides every 2–3 weeks until buds open, especially in damp conditions. Always wear protective gear when applying treatments.

🏠 Shelter Prep

• Chrysanthemum blooms are easily damaged by rain and wind. If showing your Mums plan to cover or shelter your plants by early to mid-September to protect your blooms as they begin to open.

• Options include simple hoop houses, temporary shelters, or even individual plant coverings.

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A Friendly Note

If all this sounds like a lot—don’t worry! I’ve had seasons where I didn’t go the extra mile with my mums, and they still performed beautifully. The key is patience and a little cooperation from Mother Nature. Some of the later-blooming varieties might not start showing off until late October or even early November, but they’re always worth the wait. These tips are here for anyone wanting prime, show-quality blooms, but chrysanthemums are resilient and forgiving. This year, Homecoming and French Vanilla are the first to bloom in my field, and they’re a beautiful reminder of what’s ahead as the season shifts.

Heirloom Chrysanthemum Fall Charm showing off!

The Payoff

Heirloom chrysanthemums require extra attention, but their stunning, intricate blooms make every bit of effort worthwhile. These flowers carry history in their petals and are a true symbol of the season’s change. If you bought Mums from me this spring, I'd love to see pictures. Tag me @FreedomFarmFlowers with you blooms and we can grow together!