October 2025 - Preparing Perennials for Winter
Apr 01, 2026
How to Prepare Perennials for Winter and Reduce Pest Problems
As the growing season winds down, preparing perennials for winter is one of the most important steps you can take to ensure strong performance in the spring. In the October edition of Koppert Corner, published through GrowerTalks, we focused on how proactive plant health and pest management strategies can make a significant difference before plants go dormant.
What happens before winter often determines how plants perform after it. Strengthening root systems, reducing pest pressure, and improving overall plant health now can lead to better growth and fewer problems later.
Why Pre-Winter Preparation Matters
In this month’s Koppert Corner, we emphasized that many pests and diseases do not disappear in winter. They carry over.
Insects like spider mites, thrips, aphids, and mealybugs can overwinter in plant material or containers, only to reappear in early spring when new growth begins. At the same time, root and foliar pathogens can remain active or become established if conditions are favorable.
Taking action before winter helps reduce these risks and gives plants a cleaner start when they begin growing again.
Strengthening Plants Before Dormancy
A key part of preparation is improving root health before temperatures drop.
Beneficial microbes that colonize the root zone can help plants take up nutrients more efficiently and support stronger root development. Applying these early, several weeks before consistent cold weather, gives them time to establish and begin working alongside the plant.
This added support can improve plant resilience going into winter and help plants recover more quickly in spring.
Managing Pests Before They Overwinter
Another important focus is reducing pest populations before plants are shut down for the season.
If pests are active going into winter, they are more likely to survive and become a problem later. Applying treatments to reduce populations now can prevent them from carrying over and causing damage to new growth.
In some cases, combining approaches, such as targeting both insects and pathogens at the same time, can provide broader protection and simplify late-season management.
Timing Makes the Difference
One of the most important takeaways is that timing plays a major role in success.
Biological and plant health products need time to establish and become effective, which means applications should be made before cold temperatures slow or stop plant and microbial activity. Waiting too long reduces their effectiveness and limits the benefits they can provide.
Planning ahead and applying treatments at the right time ensures they can do their job before winter conditions set in.
What This Means for You
For growers and retailers, the takeaway is to treat fall as a critical transition period, not the end of the season.
By improving root health, reducing pest pressure, and applying preventative strategies early, you can set your plants up for a stronger start next season. Even small steps taken now can prevent larger problems later.
The Bottom Line
The insights shared in Koppert Corner highlight that successful overwintering starts before winter arrives. By focusing on plant health, pest prevention, and proper timing, growers can reduce risk, improve plant performance, and carry cleaner crops into the next growing cycle.
This article is based on the Koppert Corner published in GrowerTalks and adapted for NaturalEnemies.com. To check out the original article, click here: Prep Perennials for Winter; Chlorotic Poinsettias; Pepper Production
Want more quick takes from Koppert's Corner on Grower Talks?
Type 3 Predatory Mites - March 2025
Cleaning Up Flowering Tropicals - April 2025
Pesticide Resistance Residues on Garden Mums - May 2025
Prevent Fungus Gnat Larvae - June 2025
Problematic Thrips on Poinsettas - July 2025
Mealybug Tag-team Takedown - August 2025
Just a dip won't do - November 2025
Gerbera and Hydrangea - December 2025
