While interning under the Conservancy’s Stewardship Manager Cris Sarabia and in partnership with the California Native Plant Society, I helped develop and implement a sustainable solution to nursery pot sterilization. Disinfecting nursery pots has traditionally taken a lot of time, water and chemicals. Yet sterilization is necessary to prevent pathogens like Phytophthora, a microscopic water mold, from infecting nursery stock. Unchecked, these pathogens can then also spread to landscapes when infected nursery plants are unintentionally transplanted.
To reduce use of chemical disinfectants and save time and water, we solarized nursery pots in the greenhouse. Greenhouse solarization sterilizes pots sustainably by allowing solar energy to reach high temperatures for long enough to kill pathogens. Testing with an infrared thermometer helped guarantee nursery pots reached and maintained temperatures above the minimum required for sterilization. Because of the high amount of energy needed, solar pot sterilization can only occur in summer. The Conservancy’s supply of solar-sterilized pots is expected to last until next summer. This successful, sustainable sterilization technique in now one of the Conservancy’s best management practices. Nursery staff members are looking forward to sharing this technique at collaborative workshops with other nurseries.