How to Overwinter Impatiens for Continued Growth Year After Year

Impatiens are popular flowering annuals that provide vivid color in shady beds and borders. While technically considered annuals, there are some techniques gardeners in frost-prone areas can use to overwinter impatiens from one year to the next. With proper care during the winter months, it’s possible to save impatiens and enjoy their cheery blooms again the following spring.

Why Overwinter Impatiens?

Overwintering impatiens offers several advantages compared to purchasing new plants each spring:

• Save money instead of buying new plants and seeds every year

• Maintain favorite heirloom varieties that may be hard to find at nurseries.

• Get a jumpstart on growth and flowering earlier in the spring season.

• Reduce the risk of introducing diseases by planting the same plants rather than new ones.

• Enjoy larger and bushier plants in their second year of growth.

• Add interest to indoor plant displays over the winter months.

Criteria for Overwintering Success

Several factors determine whether impatiens can be successfully overwintered in your area:

• Climate – Typically only works in zones 8-11 where winters stay above freezing. Providing artificial heat allows overwintering in zones 2-7.

• Varieties – Standard impatiens rarely survive winter. Look for perpetual or Reiger impatiens

• Preparation – Plants must be moved indoors before frost and pruned back by one-third to one-half.

• Cultural conditions – Overwintered plants require bright, indirect light, warm temperatures of 60-70°F, and high humidity.

Steps for Overwintering Impatiens

Follow these tips to increase your chances of successfully overwintering impatiens:

Select Appropriate Varieties

Choose cold-hardy varieties suited for overwintering such as:

• Evergreen impatiens hybrids – Harmony, Accent, and Victory series

• Perpetual blooming – Florific, Fiesta, and Celebrette

• SunPatiens impatiens – Vigorous roots and immune to downy mildew

Prune Back Foliage

In early fall after the first light frost, prune back impatiens foliage by one-third to one-half. This redirects energy to the roots for winter survival. Make cuts just above leaf joints using clean, sterilized pruners. Remove any spent flowers or yellow, dead leaves.

Dig Up Root Balls

Carefully dig up the entire impatiens plant including the root system. Knock off any excess soil clinging to the roots. Trim away any dead or damaged roots.

Allow Tubers to Dry

Place the freshly dug up roots and tubers in a dry, airy spot out of direct sun for 1-2 days. Allowing them to cure reduces the risk of rot developing during winter storage.

Disinfect Storage Containers

Before storing impatiens for the winter, thoroughly clean any pots, trays, or other containers to be used with a diluted bleach solution. Rinse well and allow to dry.

Pack Tubers in Storage Media

Place dried tubers in trays or pots filled with damp peat moss, vermiculite, perlite or shredded paper. Completely cover the tubers with the media. Pack them close together but don’t crush or squeeze.

Move Containers to Cool Location

Store packed impatiens tubers in a cool basement, garage, or climate controlled storage room. Ideal conditions are 45-60°F and 50-60% humidity. Avoid temperature fluctuations.

Check Moisture Levels

Check stored tubers every 2-3 weeks during winter. Gently poke your finger into the media to check moisture. Water just enough to keep barely damp, taking care not to overwater.

Monitor for Rotting

Immediately remove any softened or rotting tubers to prevent disease spread. Keep the media fresh and replace if fungal growth is apparent. Expect some loss over winter.

Transplant in Spring

After the last spring frost, transplant viable tubers back outdoors in rich soil after hardening off. Pinch back any leggy growth and water well as they re-establish. Apply fertilizer once vigorous new growth emerges. Enjoy!

Fill Gaps with New Plants

Even with the best care, some stored tubers will fail to thrive. Fill any bare spots in your impatiens beds with fresh nursery transplants. Combining new and overwintered plants guarantees the fullest flower beds.

Troubleshooting Overwintered Impatiens Issues

Proper care is required to achieve success overwintering impatiens. Here are some common problems and solutions:

Rotting tubers – Allow tubers to dry before storage, change media if fungus present, avoid excess moisture.

Shriveling and death – Store tubers without crushing at proper temperatures and humidity levels.

No regrowth – Expect only about 50% of tubers to survive. Purchase new plants as needed.

Regrowth dies – Gradually harden off overwintered plants before placing outside.

Leggy regrowth – Prune back dead stems, move to full sun, and fertilize transplants.

Flowers but no leaves – Pinch off blooms to redirect energy into foliage growth. Move to partial shade.

Caring for Impatiens Over Winter Indoors

Impatiens can be overwintered indoors in areas with freezing winters if proper growing conditions are provided. Here are some indoor overwintering tips:

• Place in a bright, sunny south or west facing window. Supplement with grow lights if needed.

• Keep ambient temperatures steady between 60-70°F. Avoid drafty locations.

• Group plants together and use a humidifier to maintain 50-60% relative humidity.

• Water whenever the soil surface feels dry but avoid saturation or standing water.

• Apply diluted liquid fertilizer every 2-3 weeks during active growth periods.

• Monitor for pests like whiteflies, aphids and spider mites which thrive indoors.

• Prune back any leggy growth to encourage bushiness. Pinch off spent blooms.

• Transition plants back outside in spring once nighttime temps stay above 55°F.

Enjoying Impatiens Year After Year

While impatiens are technically annual flowers, gardeners in frost-free climates or those willing to provide special overwintering care can enjoy these beautiful plants for many seasons. Follow best practices for pruning, digging, drying, storing, and replanting tubers to successfully overwinter impatiens. With extra effort, these colorful flowers can brighten your garden year after year.