Our recent spell of warm weather provided a good opportunity for fall cleanup of crops and fields for the winter.
Hopefully you have many of your outdoor tasks completed and are left with the last few fields from late plantings.
Another cleaning task that should be done is a thorough cleaning and disinfecting of your greenhouses.
By doing this now, you will be ready for the next growing season early and not left scrambling to prepare right before your plants arrive in the spring.
Start with a thorough cleaning. Remove all weeds, plant debris, extra pots and trays, tools and extra media, and any other items left in the greenhouse.
Eliminating weeds in your greenhouse now can help with insect and disease management in the spring growing season.
Follow up with a good sweeping to remove loose materials, and then use specialty products to remove algae, dirt and other hard-to-clean materials from surfaces. Consider power washing for tough-to-clean areas.
Start at the upper part of the structure and work down, remembering that disease-causing organisms can be found anywhere. Even if you do nothing more than this now, you have taken an important first step.
By removing live weeds and other plant material you are eliminating potential overwintering sites for diseases and insects. If you have a recurring weed problem, you might consider installing a weed barrier to reduce plant growth in those troubling areas.
Tips on Disinfecting
After cleanup, wash and disinfect empty benches, potting areas, storage shelves, tools and leftover cell packs and flats that you plan to reuse.
Your disinfecting solution can contain any of the approved sanitizing products such as Green-Shield, Physan 20, KleenGrow, ZeroTol, OxiDate, SaniDate, or other labeled material.
Be sure to follow the manufacturer’s directions when using any commercially products. Particularly note if the area to be sanitized needs to remain wet for a certain length of time. Some materials work on contact, while others require a soaking period.
Some growers use chlorine bleach (10% solution) for sanitizing, but this is only recommended for use on pots and flats to be reused — not on floors, benches and walls.
If you are using a 1 to 9 bleach solution, remember that it requires a 30-minute soak to be effective and the presence of soil or other organic matter reduces the effectiveness of the solution.
Be sure to rinse materials treated with chlorine in clean water after soaking. Also, while chlorine bleach is an effective sanitizer, please note that there will be a 50% reduction in the strength of a chlorine solution after just two hours.
Therefore, you need to prepare a new solution each time you plan to sanitize. This includes a new solution after lunch if you started working in the morning.
Note that chlorine is corrosive and repeated use may damage plastics and metals. And since chlorine can irritate the respiratory system, it should only be used in areas with adequate ventilation.
While a disinfectant will probably never be 100% effective, any reduction in disease spores will be an advantage as you start your next crop in the greenhouse.
As you clean your greenhouse, consider what materials your benches and tables are made of. Are they easily cleaned and sanitized materials such as wire and metal, or hard-to-clean materials such as wood?
If possible, consider replacing wood or other hard-to-clean materials with newer and easier to clean materials whenever possible.
Finally, after cleaning and sanitizing your greenhouse, be sure to keep it that way until spring. Do not bring in house or other plants to overwinter there as you could potentially just be reintroducing diseases or insect pests.
Hopefully you have some space in the house for special plants that your family wants to keep for next year.