Fall is one of the most beautiful times in the garden—the air turns crisp, the leaves glow orange, red, and gold, and the light takes on that dreamy, golden hue. Yet as the season shifts, those same cool evenings that make fall so inviting can also spell danger for delicate plants.
A sudden cold snap can blacken leaves overnight, damage roots, or kill warm-weather favorites altogether. Whether you garden in containers on a patio or across sprawling beds, it’s not too late to take action. With a few smart steps, you can protect your plants and extend their beauty well beyond the first frost.
Here’s everything you need to know to stay one step ahead of the cold weather ahead.
Know When Frost Is Coming
Every region has an average first frost date, though the timing can vary widely depending on where you live. In northern areas, it often arrives as early as late September, while in warmer southern zones, frost may not appear until late November or even December. Local conditions—such as elevation, proximity to water, and how sheltered your garden is—can shift that timing by a week or more in either direction. A garden in a valley may frost several days earlier than one on a sunny hillside, while urban and coastal areas often stay milder longer.
Keep an eye on the forecast for nighttime lows around 36°F (2°C) or below, especially on calm, clear nights when heat escapes quickly from the soil. That’s when frost crystals form on leaves and petals, sometimes turning tender plants to mush by morning.
Not sure when your first frost is expected? Find it fast with Swan’s Interactive Planting Zone Map! Just click the Get Growing! link at the top of Swanhose.com or visit this link and add your ZIP code in the search bar: bit.ly/3HASIxFs. You’ll get your USDA Plant Hardiness Zone and estimated last spring and first fall frost dates to help you plan ahead.
Which Plants Need Protection
Some plants can handle a light chill, but others wilt at the first hint of frost. These tender favorites deserve extra attention:
Annuals
- Impatiens: These shade-loving bloomers collapse quickly in cold weather. Cover or bring indoors before the first frost.
- Begonias: With soft stems and lush leaves, begonias blacken almost instantly when temperatures dip below 40°F.
- Basil: A true heat lover, basil leaves turn black and mushy even in light frost. Harvest remaining leaves ahead of time for pesto or drying.
- Coleus: Known for its vibrant foliage, coleus can’t survive cold nights. Take cuttings now to root indoors and enjoy through winter.
- Tomatoes and Peppers: Fruits can be harvested green and ripened indoors. Cover plants overnight if a surprise frost threatens.
Tender Perennials
- Dahlias: Their showy blooms can survive mild chills, but the tubers won’t. After frost kills the foliage, dig up and store the tubers in a cool, dry place.
- Geraniums: Before frost, prune and pot them up to overwinter indoors in a bright window or cool, dry spot.
- Caladiums: These tropicals go dormant when nights get cool. Gently lift and store their bulbs in peat moss until spring.
- Cannas: Dig up the rhizomes once frost hits the foliage. Let them dry; then store in paper bags or crates in a frost-free area.
- Elephant Ears: Like cannas, these tropicals hate cold. Lift and store their bulbs after the first frost, or move container-grown plants indoors.
Strategies to Shield Plants
Cover Up Before Nightfall
When frost is predicted, cover plants in the late afternoon, well before the temperature drops. Use breathable materials such as:
- Garden hoops with floating row covers for raised beds
- Bed sheets, burlap, or frost cloths for garden beds, deck planters, and window boxes
- Buckets or overturned pots for small plants
Tip: Avoid placing plastic (such as plastic bags and tablecloths) directly on the foliage. It traps moisture and can “burn” leaves when temperatures rise again. If you must use plastic, create a tent with stakes so it doesn’t touch the plants.
Remove covers in the morning once temperatures rise, so plants can breathe and absorb sunlight.
Mulch Generously
Apply 2–3 inches of organic mulch—shredded leaves, straw, or wood chips—around the base of perennials and shrubs. Mulch acts as insulation, trapping warmth in the soil and protecting roots from temperature swings.
Water Before a Frost
It may sound counterintuitive, but watering before a frost actually helps protect your plants. Moist soil retains heat better than dry soil. Water in the afternoon (not evening) so the soil has time to absorb warmth from the sun before nightfall.
Move Containers Indoors or to Sheltered Spots
Potted plants are especially vulnerable to frost since their roots are more exposed to cold air. Even hardier perennials can suffer in pots if left outside unprotected because containers don’t have the earth’s natural insulation to buffer temperature swings. A single night of frost can freeze the soil inside a pot solid, damaging roots or even cracking the container itself.
Low-lying areas in your yard often get frost first, while plants near buildings, stone walls, or under tree canopies tend to stay slightly warmer thanks to radiant heat and shelter from wind. If possible, group containers together near a south-facing wall or covered porch, where they’ll benefit from reflected warmth and shared humidity. Terracotta and ceramic pots are especially prone to cracking in freezing weather, so move them to a protected space or slip them into plastic nursery pots. You can also wrap the outside of pots with burlap, bubble wrap, or layers of newspaper to provide insulation.
For smaller plants, try nestling pots close to the ground and covering them overnight with bed sheets, burlap, or frost cloths. Even this simple step can make a few degrees of difference—often just enough to keep them thriving until morning.
To further protect your potted plants, raise containers off the ground by setting them on pot feet, wooden planks, or bricks. This keeps them from sitting directly on cold surfaces that can draw heat away from roots.
If you’d like to add a little warmth—and a lot of atmosphere—try weaving a strand of incandescent holiday lights among your potted plants, window boxes, or deck planters. These traditional bulbs give off just enough gentle heat to protect roots and foliage from light frost, while creating a soft, inviting glow on chilly evenings.
Tip: Avoid LED lights for this purpose, as they don’t produce warmth.
Long-Term Solutions for the Season Ahead
If you’d like to garden deeper into fall—or even winter—consider small upgrades that make a big difference:
- Cold frames and cloches act like mini-greenhouses, perfect for lettuce, spinach, and herbs.
- Row covers or hoop houses protect tender greens from light frosts and allow you to harvest later into the season.
- Overwintering indoors: Bring in potted geraniums, citrus, or tropical plants before nighttime temps drop below 50°F.
Use Hose Accessories Wisely
Tip: If the temperature is expected to drop below freezing, disconnect your garden hose from the water source and drain it completely. Water left inside can expand and crack the hose or fittings. Store hoses coiled in a shed, garage, or basement to extend their life.
If you need to water or clean outdoors after frost, reach for Swan’s ThermaFLEX® Cold Weather Hose. Thanks to its thermal-conducting jacket, ThermaFLEX stays strong, flexible, and reliable down to -30°F. Plus, Swan’s proprietary compound helps protect the hose from cracking or bursting when water inside the hose freezes, so you can water, rinse, or wash with confidence all season long.
A Little Preparation Goes a Long Way
Frost may signal the end of summer’s abundance, but it doesn’t have to mean the end of your garden. With a few proactive steps—covering, mulching, and watering—you can safeguard your plants and keep your garden thriving longer into fall. By the time your neighbors are packing up their tools, you’ll still be enjoying bursts of color and life in your yard!
