How to Use Frost Cloths, Row Covers, and Cloches to Protect Flower Beds

ByStephen Albert

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Protecting flower beds from frost doesn’t have to be complicated. Whether you garden in a warm-winter region that gets only occasional cold snaps or a cold-winter climate with regular freezes, frost protection tools can make all the difference. Frost cloths, row covers, and cloches create a protective buffer that shields tender plants, extends bloom time, and reduces cold damage.

After decades of gardening year-round in Sonoma Valley—with quick dips below freezing but not prolonged deep cold—I’ve relied on all three methods to keep annuals and perennials alive and flowering through winter and early spring. In colder USDA zones, these tools are even more essential, offering a first line of defense when temperatures plummet.

Why Frost Protection Matters

  • Prevents cell damage: Freezing temperatures rupture plant cells. A protective barrier traps warmer air around foliage.
  • Extends blooming: Light frost protection can keep cool-season flowers blooming weeks longer.
  • Reduces dieback: Perennials and tender annuals experience less leaf scorch and stem death.
  • Saves replanting costs: Many plants survive winter with simple protection—no need to re-buy in spring.

Frost Cloths: Lightweight, Breathable Protection

Frost cloth (also called garden fabric or floating row cover) is a breathable, reusable fabric that shields plants from cold, wind, and light freezes.

Key Benefits

  • Protects plants down to 28–30°F (fabric weight varies).
  • Lets in water, light, and air—no overheating on sunny days.
  • Flexible for covering beds, shrubs, or containers.

How to Use

  • Drape directly over plants, allowing slack for growth.
  • Anchor edges with boards, rocks, or landscape pins to stop cold air from seeping underneath.
  • Use double layers during hard freezes.
  • Remove once temperatures rise above freezing to prevent condensation buildup.

Warm vs. Cold Winter Zones

  • Warm zones (8–11): Use cloth mainly for occasional frosts or to protect tropicals and tender perennials.
  • Cold zones (3–7): Use heavier-weight frost cloth and double layers during severe cold spells.

Row Covers: Protection for Beds and Borders

Row covers use frost cloth supported by hoops or frames, creating a small, insulated tunnel.

Benefits

  • Warmer air layer forms under the cover.
  • Prevents frost settling directly on leaves.
  • Adds wind protection and reduces winter desiccation.

How to Install

  • Insert hoops every 3–4 feet using wire, PVC, or fiberglass rods.
  • Pull frost cloth tightly over hoops but leave enough slack for snow load.
  • Secure ends well—wind can lift covers easily.
  • Vent on warm days to prevent overheating in sunny climates.

Warm vs. Cold Winter Zones

  • Warm zones: Use for tender annuals, lettuces, snapdragons, and early spring transplants.
  • Cold zones: Essential for overwintering hardy annuals (poppies, larkspur, calendula) and young perennials.

Cloches: Spot Protection for Individual Plants

Cloches provide targeted frost defense for prized plants, seedlings, or container flowers.

Types of Cloches

  • Plastic domes (store-bought or DIY from milk jugs)
  • Glass bell cloches
  • Plastic bottles with bottoms removed
  • Wire frames wrapped in plastic or frost cloth

How to Use

  • Place over plants before sunset to trap heat from the day.
  • Open or remove during the day to prevent overheating.
  • Anchor lightweight cloches with garden staples or soil.

When Cloches Work Best

  • Protecting newly planted annuals in fall.
  • Shielding tender flowers from surprise early spring frosts.
  • Covering container plants that are more exposed to cold.

Layering Protection for Extreme Cold

In both warm and cold regions, combining methods increases protection:

  • Row cover + frost cloth for hard freezes
  • Cloches + frost cloth for tender seedlings
  • Double-layer row cover for long cold spells
  • Frost cloth under plastic sheeting (plastic never touching foliage)

Practical Tips from Experience

  • Always cover before dark: Protection works best when the heat of the day is still trapped in the soil.
  • Avoid plastic directly on plants: It transfers cold and can cause freeze burn.
  • Label and store: Fold frost cloths when dry and store in breathable bins to prevent mildew.
  • Check for pests: Covers create warm microclimates that can attract aphids and slugs.
  • Use clothespins or binder clips: Quick, effective anchors for cloches and small covers.

Which Flowers Benefit Most?

Warm Winter Regions (Zones 8–11)

  • Geraniums
  • Petunias
  • Coleus
  • Zinnias (early fall)
  • Begonias
  • Impatiens
  • Dahlias (cut down and cover tuber area)

Cold Winter Regions (Zones 3–7)

  • Hardy annuals that thrive under cover:
    • Poppies
    • Larkspur
    • Calendula
    • Sweet peas
    • Dianthus
  • Fall-planted perennials and bulbs
  • Newly transplanted shrubs or roses

Final Thoughts

Frost cloths, row covers, and cloches are inexpensive, adaptable tools that give you a long seasonal advantage. Whether you deal with light frosts or weeks of subfreezing temperatures, these simple barriers can protect blooms, save tender plants, and help your garden transition smoothly from fall to spring.

Stephen Albert is a horticulturist, master gardener, and certified nurseryman who has taught at the University of California for more than 25 years. He holds graduate degrees from the University of California and the University of Iowa. His books include Vegetable Garden Grower’s Guide, Vegetable Garden Almanac & Planner, Tomato Grower’s Answer Book, and Kitchen Garden Grower’s Guide. His Vegetable Garden Grower’s Masterclass is available online. Harvesttotable.com has more than 10 million visitors each year.

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