Food Safety & Hydroponics

Posted in Food Safety,Our Blog on March 8, 2019

At first glance, you might expect that growing produce hydroponically would be safer than growing it in an outdoor environment. Hydroponic environments are controlled, after all. They’re indoors. You don’t have to deal with any of that nasty soil; the messiness and unpredictability of the biological world is kept to a minimum. So, Food Safety & Hydroponics are a match made in heaven, right? Maybe not…

Unfortunately, even without having to deal with soil, or the great number of living things that one finds outdoors, there’s still a lot of messiness involved in hydroponic farming. Water laced with nutrients isn’t just a medium that’s appropriate for growing plants; it’s also one fit for the growth of bacteria, which generally thrive in moist environments.

That means that you can’t take the plant out of the soil and expect that it’ll solve all of your food safety problems. We still have to be vigilant when dealing with hydroponics; we have to be prepared for the ever-present possibility that pathogenic bacteria will make a home on the plants and food that you’re growing hydroponically.

There are other concerns…

There are other concerns as well. Growing fruits and veggies in a building does come with certain benefits. It should protect plants from the leavings of birds or farm animals. If you’re growing something on a farm, it can be hard to segregate crops from incidental animal waste, which can wash through with irrigation, arrive unexpectedly from above, or be introduced as fertilizer. Those problems aren’t as prevalent indoors.

Keeping something indoors also provides some protection from other pests. It depends on how your facility is constructed, of course, but growing your veggies inside could potentially keep them safe from pesky insects that you would otherwise have to use pesticides to deter. That’s also true for weeds. If you’re growing in a hydroponic medium instead of soil, you don’t have to worry about other plants stepping in and strangling out your crops.

Depending on your setup, growing hydroponically could allow you some control over fungus; you may be able to filter the spores out of the air or provide a hermetically-sealed setup where they can’t get in in the first place. That could mean that you don’t have to use fungicides, or don’t have to use as many.

So: in theory, growing hydroponically could allow you to use fewer harmful inputs like herbicides, pesticides, and fungicides, and give you more control over the environment, which may help to limit the ingress of different pathogens that could grow on the food.

Unfortunately, that’s all mostly theoretical. As we mentioned up at the top, it’s impossible to maintain an environment for growing that’s entirely free of pathogens. And because you’ll be growing your plants using water and nutrients, you’re providing the food and environment that many pathogens need to grow. If you let your guard down because you think that growing hydroponically spares you from having to worry about food-borne germs, you’re making a big mistake.

Secondly, growing in a controlled environment might not entirely free you from having to use chemical inputs. The first and most obvious case here is fungus. Fungus grows from microscopic spores. That makes it nearly as difficult to manage as pathogens are. The spores can slip into even tightly managed environments, and unless you’re keeping lab-sterile conditions, it can still colonize your plants. That means you may have to employ fungicides to control it after all.

Insects can get in, too. Sure, they’re less of a threat when growing hydroponically than they would be in an open field. And they’re not so small as to be microscopic. They’re still quite small, however, and can be tracked in on the bottom of a shoe or slip in through an open door or a cracked window. Once they’ve found the plant that they like to eat, they can spread quickly, laying eggs that might be so small as to be microscopic or burrowing into the plant so that they’re difficult to dislodge. If this happens, you may have to fall back on pesticides after all.

Even if you do manage to grow your crops hydroponically without using pesticides or fungicides, or having dangerous bacteria take root in the nutrient-rich medium that your plants are rooted in, you should consider that the growing is only one part of what the fruits of your labor will grow through. Once you’ve harvested your produce, it needs to be packed, shipped, and sold somewhere. All of the things you tried to avoid while growing – the pathogens, the chemical inputs, et al. – can be introduced once the produce leaves the farm. If they’re transported alongside fruits or vegetables that have chemical residue or pathogens on them, said residue or pathogens could easily be transferred.

That brings us back to vigilance. Vigilance really is the pillar of food safety; it’s the single most important quality you can bring to make sure that your food isn’t contaminated by something or another. As we said above, one of the dangers of growing things hydroponically may be that you let your guard down, thinking that the relatively-controlled environment spares you from the worry of conventional farming. It doesn’t. The food needs to be watched carefully and checked repeatedly at every step of the way between farm and table, regardless of whether that farm uses a hydroponic medium or conventional soil.

It is good to remember that Salmonella may still be an issue. According to doityourself.com,

“Although water may be circulating in some hydroponics systems, the bulk of it is static. Salmonella grows quickly in still water and is not always easy to detect. The problem gets intensified when you use chemicals to get rid of microorganisms in your stagnant garden water.

The high moisture content of the air around hydroponically grown plants encourages molds and other plant pathogens to grow and spread quickly. This can be avoided to a great extent by paying proper attention to ventilation, especially when plants are in flower or fruiting and are more vulnerable.”

In other words: no matter how you’re doing your growing, you still have to be careful. So don’t let your guard down.

By: Sean McNulty, Contributing Writer (Non-Lawyer)