Learn the steps for fall prep

As the seasons change, you’ll want to make extra considerations to ensure a smooth transition into cooler temperatures and alternative variety offerings. CropKing’s Theodore Huggins explains the top factors to keep in mind for fall crop success.

Produce Grower: What should be the top item on your list for prepping your structure for fall?

Theodore Huggins: Making sure all greenhouse coverings are tightly attached to the structure, and that all holes are patched or filled; Cleaning all greenhouse coverings of dirt or debris to allow maximum light exposure for fall and winter months; [And] if you’re in the North, removing all shade covering by September to ensure proper lighting for the fall season.

PG: What should be the top item on your list for prepping your equipment for fall?

TH: Making sure all heating elements are properly checked and are working properly. If fuel is needed, make sure you have everything topped off and ready for use. Also, make sure all fan belts are tightened, and fans are properly cleaned and sanitized.

PG: What’s important to remember when you introduce new crops into your operation?

TH: As we move into the fall and humidity and daytime temperatures begin to change, the growth style and needs of the plants growing will also change. It is around this time that slightly increasing your EC or your nutrient solution can show positive benefits—so long as the humidity and temperatures begin to decrease.

Start sowing your crops that prefer short daytime length and colder nights: spinach, chois and mustards. With the weather changing, and as we move into the preferred growing season of different lettuces, fall is the perfect time to try new cultivars of lettuce for the greenhouse.

PG: What are the best sanitation practices as you prep for the new season?

TH: As always, make sure all flooring and growing equipment have been properly sanitized, and that all summer algae buildup is removed. Make sure all plant debris and weeds that have accumulated throughout the summer are removed. These are harbors for overwintering bugs.

If a wet wall is used, make sure the wet wall and all its components are thoroughly cleaned of algae build-up and debris. This will save you time come next spring when you use them again.

Clean out and sanitize all irrigation equipment. This will help deter anaerobic bacteria from decaying algae or plant roots that might have entered the irrigation system—and also help prevent pathogens like Pythium from developing in your irrigation system.

PG: When it comes to lighting, what can you expect as the season changes?

TH: For more greenhouse crops like lettuce or other greens, the change in light and temperature from the summer to fall is actually beneficial to the growth and taste of the plants. In order to keep the same summer cycle of lettuce (usually 6 weeks), using this resource will help you identify the difference in daylight lengths and show you how long supplemental lighting will be needed in order to match production cycles.

Since indeterminate crops like tomatoes are climacteric, the crop in nighttime temperatures throughout the fall will actually help steer the plants generative and help increase the fruit load. But if you wish to push the plants until the end of fall and into the winter, now is the perfect time to get acquainted with your daylight lengths, the plants’ molar requirements of light and the supplemental lighting needed to keep production at its peak.

In order to keep maximum production through the fall and winter, the following DLI requirements are needed by the two most common hydroponic greenhouse crops:

Lettuce and other greens

(DLI) Daily Light Integral of 14-18 mols/m²/d1 (moles per meter squared per day)

Tomatoes

Seedlings 6-9 mols/m² /d1

Developed plants 20-30 mols/m² /d1

If supplemental lighting is not an option, the use of CO₂  being pumped into your greenhouse at levels of up to 1,200 ppm can help combat the falling daylight lengths and help keep production slightly regulated.

It is best to write the proposed costs of C0₂  and supplemental lighting down and figure out if one is better than the other for your operational needs and budget.

PG: What about pests? Will there be any differences in what you might expect as temperatures drop?

TH: Fall and winter are the times when pests begin dormancy. The cleaning of all plants’ debris—in and around the greenhouse—will help stop pests from going through dormancy in and around your house. Now is the time to make sure all insect screening is properly secured and that all fans, when not in use, either have insect screening or are securely closed to not let pests in.

PG: As farmers markets begin wrapping up, where else can you look to market your product? What other possibilities are out there during this time?

As we move into fall and winter, now is a good time to see if your local schools or community-based organizations are in need of any produce. Expand your consumer base by researching local indoor markets that run throughout the winter.

More and more greenhouse growers and other farmers are turning toward to Community Supported Agricultural model, which means giving an allotted amount of produce each week to the members that sign up for your CSA. Which, in the season when farmer’s markets dwindle, could show a positive impact for your local community and your connection to them.

Another great option is to increase your donations to qualified charities. Everyone needs a tax break.