Should I Cover Mums In Frost?

When It Makes Sense

• Good fit: You have potted mums that are still blooming or setting buds, and the forecast calls for a light, brief frost. Container plants are more exposed to freezing temperatures because their roots lack the insulation of garden soil, so a cover can reduce frost damage to flowers and foliage.
• Good fit: You have hardy garden mums with unopened buds and only an overnight dip near freezing is expected. A temporary cover may protect tender blooms and give the plant a few more days or weeks of color before dormancy.

When You Should Avoid It

• Warning sign: A hard freeze or prolonged cold period is forecast. Lightweight covers are usually not enough to protect mums when temperatures drop well below freezing for several hours, and wet or frozen fabric can weigh down and damage stems.
• Warning sign: The mums have already finished blooming, are going dormant, or are located in a windy, exposed area. Covering dormant plants offers little benefit, and covers that flap or touch foliage can bruise leaves or break branches.

Pros and Cons

Pros

• Covering can protect open blooms and unopened buds from light frost, preserving the display longer.
• It may extend the flowering season by shielding plants from brief temperature dips in early fall or late autumn.

Cons

• Covers that rest directly on leaves or hold moisture can cause bruising, fungal problems, or broken stems when they freeze.
• Frequent covering and uncovering is labor-intensive, and it cannot save plants during a severe or extended freeze.

Decision Checklist

• Is the forecast for a light, brief frost, or a hard freeze lasting several hours?
• Are the mums potted or planted in the ground, and are they still blooming or holding buds?
• Do I have a breathable cover and stakes or a frame to keep it from touching the plants?

Alternatives to Consider

Move potted mums into a sheltered garage, porch, or near the house during cold nights instead of covering them. For in-ground plants, apply winter mulch after the ground freezes to protect roots, or choose cold-hardy mum varieties suited to your growing zone. In some cases, the simplest option is to accept that frost ends the flowering season and let the plant enter dormancy naturally.

Final Recommendation

Cover mums only when a light, short frost threatens plants that are still blooming or nearly blooming, with container mums benefiting most. For hard freezes, already dormant plants, or windy conditions, covering is usually not worth the effort. In those cases, move pots to shelter or focus on winter mulching. For region-specific advice on frost dates and mum hardiness, consult your local cooperative extension service or a qualified horticulturist.