Smart Overwintering for Healthy Spring Perennials
By Ron Shepard, Inside Sales Representative
Recently I spoke with a grower regarding his plans to overwinter his perennials. It reminded me of the conversations I had in early spring with growers who had been hit with root diseases and suffered losses over last winter. as the cycle begins again, the results can be measurably different for these growers by taking a few preventative steps.
Overwintering perennials subjects plants to many stresses.
Not only do you have to worry about rodents, but changes in temperature, moisture and light may make them vulnerable to many soilborne diseases.
Starting with healthy, well-rooted plants is the foundation of the program.
To keep your plants healthy, it is important to regulate temperature fluctuations, soil moisture and pH, and root development in the container. Temperatures less than 30 °F may kill the more sensitive species. It is suggested that soil temperatures be kept in the range of 30° to 34 °F for most perennials. The soil must be moist when perennials are covered, but heavy watering increases the risk of root stresses and root rots, therefore moisture content should be closely monitored.
To help avoid the most common root rot diseases caused by pathogens such as Fusarium, Rhizoctonia, and Pythium, and ultimately significantly reduce shrink in the spring, use RootShieldŽ to guard the roots during this critical time. RootShield
colonizes the roots, and through competitive exclusion prevents entry of many fungal pathogens, stopping them before damage occurs. This promotes a healthier root system, increasing root mass potential.
After the plants are covered, making routine monthly fungicide applications can be difficult and costly. With RootShield, you only need to re-apply every three months after your initial application and prior to covering. This should save you time and money, and reward you with healthy plants come spring.
RootShield Winter Maintenance for Perennials:
RootShield Granules can be incorporated into the potting soil or topdressed; RootShield WP can be mixed with water and drenched onto the plant's roots. Using RootShield will save you time and money on chemical fungicide applications. Both products are non-toxic and are very safe for workers to use (0-hr REI).
Prior to winter covering (ideally 2-4 weeks before):
Thoroughly drench plant roots using a solution containing RootShield WP at a rate of 4 oz. per 100 gallons or pot your perennials into a mix containing RootShield Granules incorporated at a rate of 1.25 - 1.5 lb per cubic yard.
Every 3 months, where practical, drench the plant's roots using RootShield WP at a rate of 2 oz. per 100 gallons.
Helpful Links:
Technical Bulletin - Perennials and Overwintering
Perennial Crop Diseases - Greenhouse Management, Aug. 2011
