Should I Cover My Mums From Frost?

When It Makes Sense

• Good fit: You have tender mums in a container or a sheltered spot where nighttime temperatures are expected to dip below 28°F (‑2°C) for a few consecutive nights.
• Good fit: A sudden forecast predicts an early hard freeze after a period of mild weather, and the mums are young or just emerging from dormancy.

When You Should Avoid It

• Warning sign: The plants are hardy, overwintering varieties that are naturally adapted to survive the local winter lows.
• Warning sign: You live in a region where frost is a regular seasonal event and the mums have successfully endured previous winters without covering.

Pros and Cons

Pros

• Reduced risk of frost‑burn on delicate foliage and flower buds, which can preserve the plant’s ornamental value for the season.
• Allows you to extend the display period of late‑season mums, especially in containers that are more exposed to temperature swings.

Cons

• Incorrect covering (e.g., using non‑breathable plastic) can trap moisture, leading to fungal disease or overheating on sunny days.
• Repeatedly covering and uncovering can stress the plant by altering its natural acclimation to cold, potentially weakening future growth.

Decision Checklist

• Is the frost forecast severe (below 28°F / ‑2°C) and prolonged?
• Are the mums in containers, near a heat‑loss surface, or otherwise more exposed than ground‑planted specimens?
• Do you have a suitable, breathable covering material (e.g., frost cloth, burlap) and a plan to remove it during the day?

Alternatives to Consider

Instead of covering, you can move container mums to a sheltered micro‑climate such as a garage, greenhouse bench, or indoor porch. Mulching heavily around ground‑planted mums improves soil insulation, and choosing hardier cultivars reduces the need for any frost protection.

Final Recommendation

If you expect an unexpected hard freeze, have tender or container‑grown mums, and can provide a breathable cover that can be removed during daylight, covering is a reasonable precaution. For hardy, established mums in typical garden beds, the risks and effort often outweigh the benefits, so rely on natural hardiness or alternative sheltering methods. When in doubt, consult a local horticultural extension or gardening professional for region‑specific advice.