Hurricane Preparation for Greenhouses

Thursday, August 15, 2024

We have officially entered the time of year where hurricanes and tropical storms are active, and pose a threat to Atlantic Canada. It is important to stay informed on the timing, and track, of all monitored storms in order to give yourself as much time as possible to come up with a plan of action and prepare the farm.

Check out Environment Canada's Hurricane Track for updated information on all monitored storms. For those of you who haven't been following yet, Hurricane Ernesto looks to be headed towards us. It is still quite early, and storms often change direction to avoid missing us entirely, but it is worth staying on top of the forecast. Even if we don't get hit with the full brunt of the storm, Beryl showed just how much of an impact that the surrounding weather system can have. 

Hurricane Ernesto's forecasted track, taken from Environment Canada's Hurricane Track. 

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Crops that are most vulnerable to weather extremes can be prioritized in order to save as much of the crop as possible. Things like cucurbits and field tomatoes are prone to splitting after heavy rain, so would fall high on the list of things to harvest before things get going. Consider postponing the seeding of new plantings or cover crops in the days leading up to a significant storm. Wind and pounding rain can cause erosion and flooding, which easily dislodges tender seedlings, or washes away the seed all together.

Preparing Your Greenhouses

Climate change brings both a higher frequency and increased intensity of extreme weather events. It is important to think about how high tunnel structures can best be built and modified to endure the extremes. The information below is a fantastic summary of experiences shared by the growers of the Vermont Vegetable and Berry Growers Association (VVBGA). Individual grower comments and references for more information are provided following the summary.

To access this resource, click here

If there is an option to remove the plastic from a structure, the chance of structural damage can be significantly reduced. While this would expose the crops beneath, and could result in crop damage and loss, the main infrastructure can be saved. It is a difficult decision to make, but ultimately compare the value of the crop to the value of the structure itself when weighing the options. For crops that are close to being done for the season, a slightly earlier end to the season could be less detrimental compared to the loss of a structure. 

If removing the plastic isn’t an option, make sure everything is sealed up as much as possible to prevent the wind from tearing things loose. Latch and brace doors and vents, re-enforce end walls, and tie the sides of tunnels down tight. Most structures will have a rating for maximum wind speeds they can withstand. Take into consideration any shelter/exposure provided by the topography of your farm as well as the up to date weather forecast to help make an informed decision. 

It is also advised to unplug electrical equipment where possible to prevent a surge once power returns, and ensure that drainage systems are cleared and ready for large volumes of water. Make sure that the area surrounding the greenhouse is clear of items that could be picked up by the wind, and that any weak/old overhanging tree branches have been removed. 

If you have a generator, make sure you have plenty of fuel and that it’s in an accessible place. If you don’t have a generator and require power for your watering system, make sure to give the crop a good water before things get going. Its always a good idea to try and have some water set aside in barrels in case of emergency.

The Aftermath

Nova Scotia has been affected by extended power outages caused by storms, major floods and wildfires. Boil orders and potential water contamination caused by drought, floods and fires have also impacted the province. Some consumers, food producers and processors or packers have even been affected by supplier actioned recalls due to the suppliers’ contaminated ingredients purchased to make their products. Due to recent events and inquiries for guidance and assistance on emergency response, Perennia Food and Agriculture Corporation has pulled together reputable links and guidance for the reader to reference should they be affected. 

To access this resource, click here.

Besides damage by wind and heavy rains, disease issues can be a big consideration after a storm event. Heavy rain can splash fungal spore or bacteria-containing soils around, facilitating the spread of infection. Crop protectant products may be washed away, leaving the plants vulnerable until they can be sprayed again, if at all. 

Wind and rain may cause physical damage to the plants themselves, causing them stress and areas of damage where infection can move in. High winds sweeping up the coast may even carry insects from elsewhere, resulting in a flush of insect pressure that would otherwise be unexpected. It is important to scout your remaining crops as soon as possible after a storm has passed so that there is opportunity to mitigate any pest pressure brought on by or worsened by the weather.

A few diseases of note: downy mildew and late blight are documented across the eastern United States. Diseases are easily blown in from the south through these systems, so keep an eye on these symptoms specifically and look into preventative spray plans where possible. High botrytis pressure typically follows these systems as well, so make sure you have a plan in place as to how you can protect your crop and reduce the impact. 

In the meantime, keep track of the forecast and plan ahead as much as possible. Stay safe everyone

-Talia