Crazy Roots in Hydroponics: : Rhizobium Rhizogenes

What Are Crazy Roots in Hydroponics?

At first glance, Crazy Roots might sound like a fun product you’d find on a grow shop shelf. But in reality, it’s a serious bacterial disease affecting commercial hydroponic systems—particularly those using rockwool or other inert growing media.

In this blog we break down what Crazy Roots are, how they spread, and most importantly—how you can prevent them from wrecking your crop.

The Cause: Rhizobium Rhizogenes

Crazy Roots is caused by the bacterium Rhizobium rhizogenes (formerly known as Agrobacterium rhizogenes). This microorganism is notorious for:

• Triggering excessive, disorganized root growth (often hairy and non-geotropic)
• Infecting wounded or transplanted plants
• Remaining active in inert media like rockwool or mineral wool
• Being nearly immune to standard fungicides

Fun fact: This same bacterium is used in genetic engineering because of its unique ability to insert genes into plant DNA.

Why It’s a Problem for Growers

Once infected, plants with Crazy Roots divert too much energy into root production—often at the expense of fruit or foliage. The root structures clog systems, reduce nutrient efficiency, and lower yields.

Key impacts include:

• Clogged outlets in NFT (Nutrient Film Technique) systems
• Lower fruit or flower yields due to resource misallocation
• Long-term contamination risk across facilities

This disease is especially damaging to large-scale greenhouses and hydroponic farms using inert growing media.

Symptoms of Crazy Roots

Wondering if your system might be infected? Look for:

How to Prevent Crazy Roots

Unfortunately, there are no approved antibiotics for hydroponic systems in most regions. So prevention is your best weapon.

Best Practices for Prevention:

• Phytosanitary Measures: Wash hands, change shoes, and avoid bringing bags or personal items into greenhouses.
• Sterile Transplanting: Avoid damaging roots of young plants during transplant.
• Grow Media Choice: Prefer peat-based or organic matter-rich media over inert options like rockwool.
• Disinfection Protocols: Regularly sanitize tools, trays, and grow rooms.
• Monitor Seedlings: Infections often start early, especially if plants arrive already exposed.

Bonus tip: Skip the handshakes—elbow bumps may not just be for pandemics!

Where Crazy Roots Are Most Common

• Eastern Europe (Poland, etc.)
• Continental Europe greenhouse hubs
• Large commercial glasshouses
• Systems using coco, mineral wool, or NFT setups

Why Fungicides Don’t Work

Many growers waste time and money treating Crazy Roots with fungicides—but this is a bacterial infection, not fungal. The only treatments that could work are broad-spectrum antibiotics, which are not approved for crop use in most countries.

Final Thoughts

“If you see too many roots on your plants, maybe you’ve got Crazy Roots.”

While I’ve never experienced it personally—likely due to avoiding rockwool systems—Crazy Roots is definitely one to watch out for. If you’ve faced it and found innovative ways to manage it without harsh disinfectants, I’d love to hear from you.

Recap: Crazy Roots At a Glance

Spread the Word

If you found this post useful, please share it with fellow growers, especially those using hydroponic systems at scale. And don’t forget to subscribe to Hydroponics Daily for more plant pathology tips, soilless science, and cultivation know-how.

Article by Dr Russell Sharp

If you are looking for an excellent fertilizer to help out with growing those roots, check out Liquid Gold!