Outsmarting Botrytis

The rainy season is here, and while nature thrives, your cut flowers may be facing a hidden enemy—Botrytis cinerea, the notorious gray mold that can spell disaster for anyone in the flower business.

Botrytis due to too much rain

While many know the basics of moisture control and fungicides, it’s the more inventive, forward-thinking strategies that will truly help you stay ahead of this destructive pathogen. Let’s break away from the usual advice and explore some real, game-changing tactics to protect your flowers during the wettest, most vulnerable time of the year.

Why is it so difficult to control?

Botrytis is tricky to control for so many reasons:

  • It’s a survivor. It’s ability to develop even under adverse conditions makes botrytis quite formidable.  The presence of botrytis is extremely hard to detect when conditions are not favorable for growth.  It’s natural defense mechanism, botrytis will lie dormant until the opportunity for the right conditions presents itself.
  • Cultural practices can contribute to the growth of botrytis.
  • Environmental conditions for production of most flowers unfortunately are also the ideal conditions for Botrytis to thrive.

Why Botrytis Loves the Rain

Botrytis cinerea is a ruthless fungus that thrives under moist, humid conditions; a perfect match for the rainy season. In nature, it feasts on decaying plant matter, but for your cut flowers, it’s a different story. Once spores settle on a bloom, they can take hold in a matter of days, turning beautiful petals into a fuzzy, gray mess that reduces your flowers to mush.

The rainy season only accelerates this process. The moisture from rain encourages the rapid germination of spores, while the humidity slows the drying process, giving Botrytis the perfect environment to spread. Without swift intervention, this mold can move from flower to flower, devastating entire batches of inventory in no time.

So how do you fight back when the odds seem stacked against you? The secret lies not just in following traditional rules, but in thinking beyond them.

How can we stop it?

Once botrytis is past the speck stage and brown or grey coloring is visible, the damage is unfortunately done.  Infected petals can be removed by hand, but this doesn’t mean the rest of the petals or other flowers in the bunch or bouquet are healthy. 

Botrytis in various stages and varieties

Once you’ve spotted stems that have visible signs of botrytis, the best advice is to remove them and throw them away immediately.  It is a shame to throw away stems, but Botrytis can spread very quickly and could mean a bigger loss in the long run.

Stems under stress are much more likely to develop botrytis.  What do we mean by stress? In the life cycle of a fresh cut flower, it can mean:

  • temperature fluctuations
  • physical damage / bad packing
  • ethylene exposure
  • condensation in packaging

Although Botrytis can be difficult to control there are things we can do to minimize it:

  • Avoid condensation on flower blooms, primarily in packaging
  • Remove any dead or decaying plant material daily, dispose of immediately
  • Keep temperature and humidity under control to avoid fluctuations
  • Be sure to clean and disinfect all surfaces and tools daily
  • Inspect flowers carefully for any signs of Botrytis when they arrive or when you are purchasing
  • Take packaging off of flowers as soon as possible so they can breathe, if packaging is part of the item you’re selling, be sure to not overstuff buckets and give plenty of room for flowers to have good airflow.
  • Purchase flowers from trusted sources, flowers treated well along their trip will be less stressed and more resistant to Botrytis.

Innovative Methods for Combatting Botrytis

The Fungus-Repelling Coatings You Haven’t Heard of

Forget about the typical sprays and powders. What if you could coat your flowers with a barrier that not only keeps water out but actively prevents fungal growth?

New hydrophobic coatings are on the rise, and they could be the game-changer you’re looking for. These advanced coatings repel water, ensuring that flowers stay dry even during the wettest conditions. By preventing excessive moisture from being absorbed, these coatings lower the likelihood of Botrytis taking root in the first place.

Some coatings even have anti-fungal properties, adding an extra layer of protection. Imagine applying a fine, invisible shield that keeps your flowers fresh longer, even when they’re exposed to high humidity or rain. This is where science meets strategy, and it’s an approach many are beginning to experiment with to extend shelf life and prevent fungal contamination.

Letting Nature Do the Work

Chemical fungicides have long been the go-to solution, but they come with their own set of problems. Not only can they be washed away by rain, but overuse can also lead to resistance. Enter biological fungicides: the eco-friendly alternative gaining momentum.

These aren’t your average sprays. Biofungicides, made from beneficial microorganisms like Trichoderma and Bacillus subtilis, work by crowding out Botrytis spores and preventing them from settling on flowers. What makes them so powerful? They offer a natural defense that isn’t only non-toxic but also resistant to rain or high humidity. Using these fungi in combination with traditional treatments creates a dynamic line of defense that’s tough for Botrytis to penetrate.

Incorporating these into your post-harvest treatment plan ensures that flowers stay protected without the worry of toxic residue or environmental impact. It’s a smart, sustainable choice that’s quickly becoming the future of flower preservation.

Technology That Works for You

Traditional humidity control methods can feel like a guessing game. But with new technology emerging in the flower industry, you no longer have to rely on trial and error. Automated humidity control systems, powered by advanced sensors and AI, now make it possible to maintain the perfect atmosphere for your flowers; neither too dry nor too wet.

These systems monitor environmental factors in real time, adjusting moisture levels to suit your flowers’ needs. With constant feedback loops, the systems can respond to even the slightest changes in weather conditions. Whether in storage or during transport, this level of precision ensures that flowers aren’t exposed to excess moisture, which would otherwise create the perfect breeding ground for Botrytis.

The rainy season demands careful environmental control, and these smart systems offer a precise, adaptable solution. If you’re looking for ways to give your flowers an edge, investing in humidity regulation technology could be a true game-changer.

 Timing is Everything

When most growers talk about Botrytis, they focus on post-harvest treatments. But what if we told you that the timing of your flower harvest could influence how susceptible your blooms are to fungal infection?

The rainy season often pushes growers to harvest flowers earlier than ideal, due to the increased threat of rain and damp conditions. However, premature harvesting can sometimes cause more harm than good.

The trick? Harvesting during specific weather windows. By monitoring weather forecasts and opting to harvest flowers during drier periods, you minimize their exposure to Botrytis-prone conditions. The goal is to find that sweet spot when the flowers are fully mature but haven’t yet been subjected to the heavy rains that encourage fungal growth.

For high-end florists, this can mean adjusting schedules or building flexibility into their sourcing methods. For growers, it may involve using weather data and analytics to time their harvests to perfection—one more layer of control in your fight against Botrytis.

Water Quality Matters

We know that flowers need water, but did you know that the quality of the water plays a crucial role in preventing Botrytis? Stagnant or contaminated water is a breeding ground for pathogens, including Botrytis. During the rainy season, when water is plentiful but often mixed with contaminants, maintaining clean, fresh water becomes essential.

Consider setting up a filtration system that prevents any harmful pathogens from entering your storage or hydration systems. If you’re using rainwater, ensure it’s collected and filtered correctly before being introduced to your flowers. Additionally, water levels should be kept shallow enough to prevent flower stems from soaking in too much liquid, as this can invite mold.

By creating a clean, controlled water environment, you not only preserve the quality of your flowers but also decrease the risk of infection.

Getting Ahead of the Problem

By the time Botrytis becomes visible on your flowers, it’s often too late to prevent widespread damage. Fortunately, technology is making it possible to detect Botrytis earlier than ever before.

Using specialized sensors and even machine learning algorithms, some flower producers now employ early-warning systems that alert them to the presence of fungal spores before they can cause serious harm.

These systems use data on temperature, humidity, and air quality to predict Botrytis outbreaks and can trigger automated responses such as increased airflow or humidity adjustments. The ability to act in real time makes all the difference in mitigating the impact of this disease.

Thinking Beyond the Basics

The rainy season doesn’t have to be a death sentence for your flowers. By embracing cutting-edge technology, sustainable practices, and a proactive mindset, you can protect your blooms from the destructive forces of Botrytis. From biofungicides to innovative humidity control and advanced coatings, there are plenty of ways to outsmart the gray mold and keep your flowers fresh, vibrant, and market-ready. The key is to think beyond the obvious, exploring new tools and techniques that offer both short-term protection and long-term sustainability.