Although the uninitiated may think that the work ends with the final harvest of the season, seasoned growers know better.Â Now is the time to repair everything thatâ€™s broken and to get things in order for a new season.
And for the days when spring weather doesn’t allow field repairs, work is the high tunnels can keep you warm, dry and productive. Â
Here are some high tunnel upgrades to consider.
Install a Temperature Alarm
This upgrade isnâ€™t about improving efficiency as much as it is about protecting your tunnels from disaster. No matter what kind of ventilation and heating systems you use, failure is always a possibility.Â Propane heaters can run out of fuel and GFCI breakers can trip in the middle of a heat wave.Â Â
Thankfully, alarms can alert you if the temperature in your high tunnels goes above or below a certain threshold.Â
And, also thankfully, these alarms can be as cheap or expensive as you want them to be.Â Â
At one farm I worked on, we wired some batteries to a megaphone and an analog thermometer. The whole setup cost maybe $30. At the other extreme, you can purchase wifi-based systems that send alerts to your phone.Â
Either way, some sort of alarm will give you the peace of mind of knowing that youâ€™re not one oversight away from losing an entire crop.Â Â
Read more: Get the most out of your high tunnels with these 6 tips.
Get Roll-Up Sides
For growers without electricity in their high tunnels, roll-up sides are a necessity. Coupled with some gable vents, they should give your tunnel all of the ventilation it needs, even in the hottest months.Â
Even for growers with the luxury of electricity, roll-up sides offer some real advantages. They:
- require no electricity
- donâ€™t come with any of the noise of an exhaust fan
- allow for a pleasant cross breeze that makes working in the tunnels a pleasure
In case youâ€™re not excited about manually rolling the sides up and down, however, you can install motors to do the work for you. You can also hook these motors up to a thermostat so that they open and close at set temperatures.
Upgrade Your Endwall Material
For those doing any sort of season-extension growing in their tunnels, improving insulation is well worth the effort. One of the best ways to improve your tunnelâ€™s energy efficiency is to upgrade your endwall material to something with a higher insulation rating.Â Â
Corrugated or double-layer polycarbonate works well on sides that you want to allow light in from. For north-facing (or already-shaded end-walls), consider paneling the outside of the wall with boards and hanging some sort of rigid insulation on the inside.Â
Your propane bill will never be the same again.
Read more: Think about your high tunnel irrigation system now, not later.
Put in Perimeter Insulation
If youâ€™re interested in further improving your tunnel’s insulation (and not afraid of a little digging), consider insulating the perimeter of your high tunnel. The job entails placing foam board 2 feet down around the outside of your tunnel.
Itâ€™s not a job for the faint of heart but also wonâ€™t take as long as you think. The boards will mitigate heat loss to the outside and will retain your soilâ€™s warmth well into the shoulder seasons.
No matter which upgrades you choose to tackle this winter, take advantage of your tunnelâ€™s balmy winter temperatures to make them function a bit better next season.