How to Keep Outdoor Potted Plants Alive in Winter - Outdoor Cabinets

With the right preparation and care, it is possible to keep outdoor potted plants thriving through the winter months. There are many techniques gardeners can use to protect container plants from cold temperatures and lack of sunlight. This comprehensive guide will provide tips and tricks for overwintering patio pots and planters successfully.

Choose the Right Plants

The first step is selecting varieties that can withstand frosty conditions. Here are some good options:

Ornamental cabbages and kales – These come in colors like red, white, pink and purple. They look beautiful dusted with frost.
Cool-season annuals – Pansies, violas, snapdragons and ornamental peppers thrive in chilly weather.
Evergreen perennials – Rosemary, lavender, thyme and sage remain attractive through winter.
Certain shrubs – Boxwood, holly and broadleaf evergreens retain their leaves.
Hardy succulents – Sedums, sempervivums and some cacti/aloes can tolerate cold.
Deciduous trees – Maples, dogwoods and birches have attractive bark to give winter interest.

Avoid choosing tropical plants like hibiscus, palms or bougainvillea that will die in freezing temperatures. When selecting plants, read labels to ensure they are rated for colder growing zones.

Use the Right Planters

Make sure pots are frost-proof and will not crack in frigid winter air. The best options include:

Concrete or resin planters – These hold up well to repeated freezing and thawing.
Wood planters – Use weather-resistant woods like cedar that can handle cold, wet conditions.
Plastic pots – Opt for heavy-duty plastic that won’t become brittle and crack over time.
Ceramic or terra cotta – Choose pots rated for outdoor use and extreme temperatures.

Avoid using fragile containers or pots that collected water can expand and break. Place gravel or stones in bottom of pots to improve drainage before adding soil and plants.

Prepare Soil Properly

The right soil mix creates an optimal root zone for plants. Here are some tips:

Use a commercial potting mix – These are porous blends suitable for container gardening.
Incorporate perlite or vermiculite – These add air pockets to improve drainage.
Mix in a slow-release fertilizer – Granular types will supply nutrients over time.
Add organic compost – This introduces beneficial microbes and holds moisture.
Check that soil drains well – Potting mix should not become waterlogged.

Preparing a quality, loamy soil provides roots warmth and nutrition to keep plants strong through harsh weather ahead.

Pick the Right Spot

Where you locate pots can make a difference in winter:

Place near walls or structures – This protects from harsh wind and blowing snow.
Use covered areas – Under entryways, gazebos or overhangs reduce exposure to elements.
Choose a southern exposure – Maximizes sunlight during darker months.
Raise pots off the ground – Sitting on feet or blocks keeps them above cold soil.
Provide wind protection – Use fencing, trees or shrubs to block prevailing winds.
Use thermal mass – Concrete, brick or stone patios give radiant warmth.

Positioning pots in sheltered, sunny spots protects from excessive cold while allowing sunlight to reach plants.

Mulch Surrounding Soil

Apply insulating mulch around potted plants before winter arrives:

Use 2-4 inches of shredded leaves – This organic material moderates soil temperature.
Try pine needles or evergreen boughs – Creates an attractive wintery look.
Consider straw or hay – Dried grasses insulate the roots and crown.
Add pebbles or gravel – Inert materials retain daytime warmth.

Mulching helps safeguard roots and prevent heaving caused by frost. Replenish as mulch decomposes over the season.

Provide Extra Insulation

For added protection, wrap or surround pots:

Bubble wrap pots – Secures insulation tightly around containers.
Use fiberfill batting – Place this insulation inside decorative planters.
Try bagged leaves/bark – Fills space between inner and outer pots.
Cover with garden fabric – Burlap holds in warmth but allows airflow.
Construct mini-cold frames – A DIY option using wood frames and plastic sheeting.
Surround with loose straw – Packs around pots to prevent freezing.
Employ commercial wraps – Breathable, weatherproof products designed for winter.

Extra insulation techniques are useful for marginally hardy plants or in regions with severe winters. Monitor carefully and remove immediately if plants begin to mold.

Apply Winter or Reflective Mulches

Special mulches reflect sunlight back onto plants:

White gravel or crushed shells – Bounce sunlight to protect roots.
Try reflective fabric sheets – Foil or mylar flashes light onto plants.
Use white marble chips or eggshells – Will not blow away like chopped leaves.
Add golf balls, ping pong balls or tennis balls – Can reuse for several seasons.
Hunt for flat white stones – Ideal inexpensive reflective mulch.

These tricks maximize solar warmth. Renew after rainfall washes particles away. Remove in spring so soil can absorb early sun.

Water Carefully

Alter watering practices for cooler, wetter weather:

Reduce watering frequency – Overwatering leads to root rot in winter.
Wait until soil dries out – Check moisture a few inches down before watering.
Water during warmest part of day – Allows it to penetrate soil when plants need it most.
Pour warm water – Helps prevent roots from shocking in cold soil.
Provide moisture before freeze – Dry soil is susceptible to frost damage.
Use soaker hoses – Prevent leaves from getting wet to avoid disease.

Check soil regularly and water only when moderately dry. Avoid overwatering that ruins potting mix and suffocates roots with excess moisture.

Clean Up Plants

Some maintenance prepares plants for harsh weather:

Remove weeds and debris – Keeps pests and diseases at bay.
Prune leggy growth – Promotes sturdy, compact shapes better suited for winter.
Cut back dead foliage – Prevents mildew and traps for pests.
Treat diseased plants – Apply fungicides prior to dormancy.
Relocate tender plants – Bring pots with tropicals indoors or under cover.
Fertilize in fall – Promotes strong roots and cold hardiness.

Proper cleaning and care makes plants less vulnerable to issues and able to focus energy on surviving the cold.

Add Winter Interest

Accessorize pots for added color and texture:

Include interesting evergreens – Juniper, arborvitae, holly.
Add winterberry branches – Bright red berries persist into winter.
Accent with twigs – Birch, dogwood, willow provide texture.
Use colorful stems – Red and yellow twig dogwoods or coral bark maple.
Add pinecones or seed pods – Natural elements complement winter pots.
Try decorative objects – Birdbaths, chimes, garden art.
String lights – Sparkling lights add festive magic.

Mixing in wintery elements makes pots more dynamic and visually appealing during gloomy months.

Use Temporary Covers

For quick protection from cold snaps, use blankets or sheets:

Burlap sacking – Breathable and blocks wind.
Old quilts or comforters – Avoid fabrics that absorb moisture.
Sturdy plastic sheeting – Weigh down edges with stones to keep centered.
Flower sack towels – Provides insulation during sudden plunges in temperature.
Cardboard boxes – Cut holes for airflow and light penetration.
Inverted buckets or pots – Place over small tender plants like mini cold frames.
Lawn chairs – Flip upside down and drape with towels or fabric.

Have materials ready to shield plants on frigid nights and remove promptly in morning.

Apply Anti-Transpirants

These waxy films prevent moisture loss from leaves:

Use commercial anti-transpirants – Apply according to label directions.
Try home remedies – Mix milk and water or liquid wax and alcohol.
Coat leaves thoroughly – Repeat applications after rainfall.
Avoid spraying flowers – Can damage tender blooms. Focus on coating leaves.

Anti-transpirants are useful for broad-leaved evergreens vulnerable to winter desiccation. They do not provide frost protection alone.

Move Pots Together

Grouping pots creates a warmer microclimate:

Place pots in rows or clusters – Retains heat among the containers.
Push pots together – So sides are touching for insulation.
Nest smaller pots inside big ones – Protects root balls from all sides.
Surround with bales of straw – Creates a sheltering wall.
Use sunken beds or pits – Sink pots in the ground and surround with soil.

Huddling pots together reduces their exposure and helps insulate roots in soil. Focus on shielding the most vulnerable plants.

Know When to Store Tender Plants

Some plants require winter storage:

Bring tropical plants indoors – Hibiscus, palms, bougainvillea, etc.
Store dormant plants in cool garage or basement – Certain bulbs, tubers, corms.
Provide cool, dark conditions – Around 45-50 degrees Fahrenheit.
Allow air circulation – Prevent mold and rotting.
Limit watering – Just enough to keep roots from drying out.
Watch for signs of life – Do not dispose of plants prematurely if dormant.

With proper care indoors, less hardy pots can survive until warm weather returns. Monitor closely during storage period.

Add Supplemental Heating

Some gardeners provide extra heat sources:

Use outdoor-safe heating cables – Place under pots to keep roots warmer.
Try self-regulating heat mats – Designed to prevent overheating.
Position pots on radiating pavers – Collects solar heat during the day.
Place pots over heat spires – Attach to base and emit warmth.
Employ outdoor light strings – Provides some warmth and prevents frost.
Use patio heaters or fire pits – Radiates ambient heat but avoid scorching plants.

Heating devices help ward off frost for borderline hardy plants during cold snaps. Take precautions against overheating, fires and electrocution.

Allow Frost Damage

Some visual damage may be inevitable:

Expect leaf scorching – Particularly on evergreen foliage.
Anticipate dead branches – Prune out in early spring.
Remove mushy roots or stems – Cut back damaged parts.
Accept some dieback – Plants will refill out as weather warms.

While unattractive, moderate frost damage is mostly cosmetic. Healthy plants will recover and resume growing when temperatures increase again.

Remove and Replace Struggling Plants

Some plants simply will not survive winter in pots:

Compost annuals after frost – Pull out dead or rotting annuals.
Discard damaged perennials – Those unlikely to recover in spring.
Replace dead plants in spring – After danger of frost has passed.
Use surviving plants in other areas – Transplant if possible.

Keep an eye on struggling plants and be willing to remove and replace those that did not make it through winter. Evaluate your choices and adjust selections for next year.

Provide Ongoing Care

Continue best practices despite cold conditions:

Inspect plants after storms – Repair toppled pots, re-cover with mulch.
Remulch as needed – Maintain a protective layer of mulch.
Check moisture levels – Water whenever soil gets dry.
Remove debris – Prevent pests and diseases.
Monitor for animal damage – Put up fencing if needed.
Prune broken branches – Avoid wounding trunks and stems.

Diligent care and maintenance throughout winter gives container plants their best chances of pulling through.

Be Patient Waiting for Spring

Have realistic expectations for potted plants over winter:

Expect slowed growth – Plants mostly rest until spring.
Do not fertilize – Wait until soil warms and growth resumes.
Set up shelters to work in – Makes winter care easier to maintain.
Keep an eye out for early sprouts – Bulbs may send up early shoots after harsh winters.
Watch for spring arrivals – Crocus, daffodils, ornamental onions.
Get ready to transition plants – Harden off seedlings and new plants going outside.

With preparation and vigilance, gardeners can help potted plants survive until warmer weather lets them thrive again.

Frequently Asked Questions: Overwintering Potted Plants

Get answers to common questions about caring for container plants through the winter:

Should I Prune Potted Plants Before Winter?

Pruning promotes plant health prior to winter dormancy. Remove dead or damaged branches which can harbor pests and diseases. Also prune leggy or overgrown plants to encourage compact shapes better able to withstand winter conditions. Avoid major pruning that stimulates new growth too close to frost.

What Temperature Will Kill Potted Plants?

Exactly how cold a plant can tolerate depends on the variety. Some pots may withstand below zero temperatures while others struggle once thermometers drop into the 20’s Fahrenheit. Check plant hardiness zones before selecting plants. Be ready to provide protection during cold snaps that plunge below a plant’s ability to survive.

Should Potted Plants Be Moved Into a Garage for Winter?

Tropical plants like palms definitely need to be brought into protected spaces for winter. However, cold hardy potted plants are often best left in place since sudden location changes can shock them. Evaluate each plant’s needs. Those rated for your growing zone can stay outdoors if properly cared for with extra insulation.

Should Containers Be Elevated in Winter?

Raising pots helps prevent damage from soil heaves caused by freeze and thaw cycles. Sit containers on feet, bricks, gravel or stands to keep them above ground level. This also helps drainage and reduces cold transfer from the earth. Insulating mulches provide further protection for raised pots.

When to Water Potted Plants in Winter Months?

While plants need less moisture during dormancy, pay attention to watering when the soil dries out. Water just deep enough to moisten the roots during warmer parts of the day. Avoid overwatering which can lead to rot and unhealthy roots. Check soil moisture before watering to ensure pots are not getting too wet.

Do Plants Go Dormant in Winter if Outdoors?

Most potted perennials, trees, and shrubs will go dormant during winter even when left outdoors. Growth slows dramatically and plants essentially hibernate until the return of warmer weather. Evergreens will remain actively photosynthesizing but at reduced rates. Respect dormancy and avoid overwatering or fertilizing resting plants.

Conclusion

Although winter poses challenges for container gardens, you can keep potted plants healthy with preparation and diligent care. Choose hardy plants suitable for outdoor life in your climate. Make sure containers and soil provide adequate insulation, drainage and nutrition. Position pots in protected microclimates and use covers and wrappings when needed for additional warmth. Adjust water and pruning practices for dormant plants. With a little time and attention, it is possible to maintain the beauty of potted plants despite harsh weather and shorter days. Rewarding months of spring growth and renewed beauty await gardeners willing to put in the effort to help potted plants thrive through winter.