Tips on How to Properly Overwinter Perennials

By Darwin Perennials|October 30, 2025

Darwin Perennials Product Representative Chris Fifo recently presented three steps that growers need to follow to achieve overwintering success with their perennials. Those steps are as follows:

Step 1: Choose the Right Varieties

Prioritize high-value crops and reliable types (tissue culture, bare root, patented/brand programs, newer seed-derived lines).
Avoid or minimize overwintering for low-value, abundantly available, or disease-prone crops (e.g., mildew-prone, bacterial-sensitive, or botrytis-prone varieties).
Some crops naturally show better flower power after overwintering; others may need chilling for optimal bloom.
Specific guidance on sedums and nepeta: Sedums can overwinter well if kept dry and properly selected; nepeta can be challenging but doable with proper culture.

Step 2: Choose the Best Growing Location

Indoor overwintering is preferred for control, although outdoors can work with precautions. Remember, indoor plants require more labor, consistent moisture management, and protection from excessive solar gain.
Cold frames and tunnels are viable mid-range options with proper coverings and temperature control.
Outdoors overwintering is zone-dependent; use cold-hardy varieties and protect with covers, moistened pots, and careful monitoring of temperature and moisture.
Mice management under frost blankets is critical; place bait stations and monitor.

Step 3: Proper Culture and Growing Techniques

Emphasize building bulk before winter: Plant early, feed heavily (avoid excessive salts and ammonia-based fertilizers late season).
For fall planting, ensure enough time for root/bulk development; long-day perennials benefit from early planting.
After foliage dies back, avoid excessive trimming that invites diseases; maintain some foliage for energy storage until dormancy.
Use preventative fungicides at the onset of dormancy and monitor for botrytis during this time.
Keep foliage dry when watering; use tools like a leaf blower to dry leaves quickly.
Monitor soil temperature and crown temperature; raise pots on risers to heat the root zone effectively when forcing or waking up plants.
Forcing vs. natural dormancy: forcing can yield uniform, timely emergence; adjust temperature to wake up plants predictably.

For additional information on overwintering success and available production resources, including how to build an effective backup plan, please read the original article found on the Darwin Perennials website.