Greenhouses have a lot more advantages compared to field production methods. These are owed to the highly profitable and controlled environments they create, allowing plants to thrive in climates, seasons, and regions they otherwise would never be able to on their own.
If your crops could have a preference of where to grow, in most cases it would be in a greenhouse rather than the open field. With the latter, they’re at the mercy of pests, elements, wind, and other factors. In a greenhouse however, they’re given the perfect conditions for them to flourish and protection from the elements.
Unfortunately, there are other things that thrive in greenhouse environments. What’s worse, these happen to be the bane of all greenhouse growers— and on this list is bacterial disease, which can have harmful and even devastating effects on your crop.
Every greenhouse grower will reckon with bacterial diseases affecting their plants from time to time. To prevent and keep down bacterial disease in a greenhouse, be sure to keep up on the following disease preventing greenhouse tips.
Ventilate adequately and properly
Every greenhouse absolutely requires ventilation—and not just any ventilation: good ventilation. It’s not just for the benefit of keeping your crops alive and breathing, either.
Yes, plants do respirate, needing fresh carbon dioxide from outside and the escape of oxygen. But this air exchange is also needed to avoid the trapping of any disease in a greenhouse, bacterial or otherwise. Lack of air exchange in a greenhouse is also one of the likely ways bacteria will enter, infect your plants, and proliferate quickly, too.
Basic side wall or roll-up vents are necessary and recommended for this very reason. Beyond that, however, the most sophisticated structures with the least bacterial disease issues have as much ventilation as possible: side vents, peak vents, solar automatic vents, ducting systems, and more.
Ensure air movement
Every expert greenhouse grower knows ventilation is nothing without fans or exhaust. Sans air movement, stale air from the outside world will get trapped in your greenhouse, helping to quickly spread bacterial disease.You’ll need to make sure air movement is encouraged within the structure, allowing currents to move in and out of the greenhouse via your ventilation systems.
On their own, most vents won’t work on their own— they will need fans or exhaust. Air circulation is especially important during warm periods when bacteria is most likely to proliferate and grow. One could say it is even more important in high humidity, which helps prevent moisture-loving bacteria from setting in.
Reduce soil contact
Besides stale air, bacterial diseases are most likely to take hold through any sort of soil contact. In fact, this is the most likely way that plants will contract a bacterial disease.
Make sure plants are not having any unnecessary contact with their soil media: whether they’re planted straight into the ground, in planters, or in raised beds— or with coir pith, peat moss, or any other type of soil-resembling medium. Growing hydroponically may help cut down on the risk of bacterial disease, though this is dependent on growers regularly keeping their systems clean.
After soil and air, water is another common bacterial disease vector. Bacteria are far less likely to take hold on crops without the help of moisture, regardless of whether the disease came from soil or stale air.
For this reason, you’ll definitely want to fine-tune your irrigation setups to avoid excessive moisture on plants. In concert with fans and air circulation, air movement within a greenhouse is a huge help to dispelling any moisture still latched onto plants, thereby greatly reducing any chances of disease.
Most importantly, irrigation should under no circumstances cause any sort of soil splash. A combination of soil and water creates the ultimate disease vector for bacteria. If your irrigation is causing soil to splash up on plants, it should absolutely be altered and fine-tuned. Overhead misters or sprinklers can cause this.
If soil splash is too much, consider drip or flood irrigation for your greenhouse instead. These methods will rid your greenhouse of any soil splash problems altogether.
Get a handle on humidity
Humidity in a greenhouse can be the most silent killer of all. Even if it doesn’t feel too humid, the levels of moisture in your greenhouse can nevertheless be conducive enough for bacteria to grow and spread.
As much as you possibly can, keep humidity levels low— as low as is acceptable for the specific crop you are growing. If you happen to be growing many different crops with different humidity needs, compensate with higher settings on fans and air circulation to make sure that moisture (and bacteria) keep moving away from your plants.
Clean up plant debris regularly
Just like soil, dead plant debris can attract and spread bacterial disease, too. Without regular maintenance, bacteria from plant debris can glom onto your healthy crops, establish infection, and potentially lead to crop damage or even a total loss.
Be sure to keep greenhouses clean. Remove dead, diseased, or fallen foliage. Sweep walkways often and stay up on any needed pruning. Organic greenhouse growers should especially stay on top of removal of weeds, which can be vectors for disease, too.
Greenhouse growers planting different crops in the same soil media should make sure to rotate what they plant every time. This is disease prevention 101 for organic growers, but it’s really a helpful approach that applies to just about any grower, regardless of their methods.
Especially if you plant into the same beds or containers again and again (without changing the soil media much), plants of the same species, varieties, and even plant families will establish the same bacterial diseases there, too. To naturally break the cycle of harmful bacteria in your soil (and thus keep down bacterial disease in your greenhouse), plant something different every season and alternate often. This is the definition of crop rotation and a widely effective disease-preventing strategy.
Keep equipment clean
Cleanliness in general is recommended for any greenhouse disease prevention. Sanitize tools, trays, surfaces, containers, and anything that contacts the soil or other media especially.
Hydroponic growers may think they’re skipping out on disease risk with a water-only medium, but they would be wrong. Bacterial disease can take hold in water quickly, so be sure to keep hydroponic growing equipment nice and clean on the regular. (Your plants and profits will thank you for it).
Use bacterial pesticides (ideally as a last resort)
Greenhouse growers can be supremely fastidious while preventing bacterial disease. But at some point, it can and does happen to the best of us.
In times when your whole crop may be threatened— and bacteria spreads quickly, no matter what you do— it may be your best last-ditch effort to turn to chemical pesticides that can kill bacteria. Organic options are out there and are more environmentally and ecologically responsible.
These can save your crop from further damage and infection, though it cannot reverse the damage in your plants that has already taken place.
Along with many other factors, bacterial disease can be one of the biggest threats to a grower’s greenhouse crops. Before it’s too late (and the damage is done), be sure to cover all your bases and stay up on these steps to keep bacterial disease down in your greenhouse.