Now, allow me to explain The Great Mint Uprising of 2020. Allow me to set the stage first: I went to visit my parents in Rockford for a long weekend. Indeed, I was in a good mood thinking about my new hydroponic herb system. In summary, four days of family bonding, no undue plant stress, and not even a peep from my roommate Dave about my so-called “plant problem.” But, when I finally returned to my Chicago apartment, I was greeted with a remarkable sight: I was standing at the entrance of a freshly minted mint jungle.
In addition to everything else, it seems that in just four days, my mint plant managed to send runners through the water channels, strangling my basil, encircling the computer towers, and sending a counterattack to my support poles. It also seems that thyme had gone into hiding and was attempting to conserve energy in her fuel reserves while oregano…. My poor, frail oregano was left a mere silhouette, compiting for light.
“Hmm,” I said to myself and my echoing home, “That’s…”
“Not ideal.”
When I tried explaining the scenario to my sister over a call, her response was nothing short of breathless laughter followed by, “You’re the only person I know who could be colonized by mint.” She was not wrong. In soil gardens, everyone is familiar with the fact that mint is the horticultural equivalent of an unwelcome houseguest who arrives for a weekend and somehow overstays their welcome for three months, couch-surfing, devouring your food, and hijacking your Netflix account. But I truly believed—and this is where seasoned gardeners are likely already chuckling at me—that a hydroponic system would be able to, in some way, contain mint’s relentless tendencies for world domination.
Spoiler alert: It did not. My foray into hydroponic herb growing began innocently enough. After what some might consider a brutal—and in my case, deeply avocational—massacring of around 17 basil plants in traditional pots (a talent I’ve honed over many years), I reasoned that I needed to part ways with soil.
Hydroponics, on the other hand, appeared to offer a solution—with total control over nutrients, no risk of overwatering or underwatering, and a clean break from soil diseases. Utilizing plastic totes, net pots, air stones, and grow lights, I constructed a simple deep water culture system. Contrary to my primary-curriculum-free engineering skills, it was surprisingly quite functional.
At first, the chosen herbs were understated. I picked orderly plants such as basil, parsley, and cilantro that would not run away. Then, a seemingly tame chocolate mint plant went ahead and drew me in on a nursery visit in spring. I believed it would be nice to have chocolate mint for summer cocktails. My first clue might have been the chocolate mint plant being separated from the rest of the plants with warning signs.
When I suggested to the worker that I could use my hydroponic system to grow it, their eyebrow with a puzzled tilted up should have been my second clue. “That might not be the best idea, but if you’re certain,” she continued, “then brace yourself because mint can be…”
“Hell yes, I know it can be invasive in the ground,” was my answer poised to bite me. “The sake of the argument, I’ll mention that it’s all but guaranteed to do this gracefully if grown hydroponically because there’s no soil to spread through. It’ll be fine.”
Unfortunately for me, that was a grave mistake.
What I did not take into account is that mint can express its growth aspirations without any form of soil. In hydroponics, mint grows faster than in soil. It has growth rates which would terrify children. Without the bounding walls of soil, the physical limitations of space, water offers mint roots and runners the freedom to traverse around corners, through narrow gaps, and, apparently, into realms that defy the very laws of physics.
Following the Great Mint Rebellion, I was confronted with an important choice: either abandon all dreams involving mint forever, or devise a method to subdue this herb while savoring its delightful taste. Stubborn as I am (which has enabled the majority of my most educational gardening disasters), I chose the latter. Thus began the journey of trying to hydroponically grow mint without letting it take over my apartment.
Attempt #1: The Isolation Strategy
As a first attempt, I tried to address the problem with a simple solution—suppress the mint’s escape by confining it to its own hydroponic system. For mint, I constructed a small single-plant bucket system at a considerable distance from the primary herb system. This solution worked remarkably well for roughly three weeks. After that, I noticed mint roots growing out of the drainage hole in the bottom of the bucket, over two inches of barren countertop, and extending toward the main system like some kind of horror movie monster.
My imagination has never run wild with survival instincts to the extent that it’s screaming for help in nature documentaries about extremophile bacteria. Attempt #2: The Barrier Method
For this approach, I tried to work within the confines of the herb system. I decided to stay in the main system but devise root barrier partitions using net pots. My hypothesis was that the fine mesh landscape fabric used to line the net pot would capture the roots of plants and still let water and nutrients enable the plant to thrive, thus, reinforcing the pot walls.
Boy was I surprised when they didn’t work. The mint mocked my feeble defenses. To their credit, props to the mesh. But I don’t think I saw my planter letting go of the pot for peace treaties. Within two weeks, roots had either found a way through the mesh or grown around the apex of the pot, once again making a grab for utter rule.This scenario was just as annoying as having a plant escape artist that was stuck on trying to escape from prison. The attempt three is “The Root Pruning Regimen.”
In the third approach, I aggressively removed the roots, what I call “mining,” on a consistent basis. Weekly, I would extract the mint from the system, cut the roots back to a manageable size, and replant it.
From a containment perspective, this method actually worked. As long as there was regular pruning, the mint couldn’t establish its supremacy. Yet, this approach did stress the plant, reducing flavor and vigor, and in addition, required weekly maintenance that was a hindrance during travels longer than a week.
This was a big issue because one of the many merits or advantages that mint had is the less rubdown maintenance work that you had to spend, which was essentially meant to defeat the purpose. Another thing that I discovered is that pruning mint roots released oils which caused your hands to smell very minty for days despite scrubbing them clean. Following what I would call an overly aggressive pruning session, I kept startling myself awake because of the smell my hands were giving out that resembled a pack of chewing gum.
The Divided System: Attempt #4
Building further on my previous attempts, for the fourth one I constructed a divided reservoir— a hydroponic system which has permanent physical barriers separating different sections. This time mint was given its own compartment with a solid divider that extended down to the bottom of the reservoir. While water could circulate beneath the divider through small holes protected by mesh, roots theoretically could not cross between sections.
Although this was an improvement over previous attempts, I soon realized that mint does not only spread through roots. It also sends out above-water runners that are able to crossover barriers and establish new systems wherever they touch water, Many times I would come home to find mint stems spanning over the divider like botanical bridges, dangling roots into other compartments. The mint had effectively taught itself to air-layer in order to get around my defenses.
The Complete Isolation Pod: Attempt #5
My fifth attempt came after cultivating some degree of respect for mint’s determination. With attempt five, I completely embraced isolation as a new approach. I started what I now refer to as a “mint containment pod,” which is simply a separate floating raft system in a transparent container with an entirely sealed top apart from one opening for the mint stem to escape.
The whole container sits within the greater hydroponic system for water circulation, however, from the root point of view, it is entirely sealed off. This finally worked. The mint grew splendidly in its containment pod as it could not sent roots or runners into the main system.
The barrier also proved efficient and the container enabled me to watch for any sttempts at escaping mint. As an added perk, the mint’s exceptional water filtration capabilities actually kept the main system cleaner as her roots absorbed compounds that would otherwise support algae growth. With finally being able to contain the mint, I was able to partake the benefits of mint grown through hydroponics and avoid the botanical imperialism.
And those advantages are important—hydroponic mint grows faster, produces more leaves per plant, and is more flavorful than soil-grown counterparts. In fact, my current choclate mint plant produces enough for 6 to 8 mojitos weekly along with garnishes for desserts and infused water. With time, I’ve made improvements to the pod system that is meant for containment. Some of the improvements include:
1.
Black-out sleeves covering the clear plastic container prevents light from the roots thus eliminating the algae issues that were troubling in previous models. 2. Having a small dedicated air stone in the containment pod guarantees enough oxygen for the sequestered root system, which increases growth rates by approximately 30 percent.
3. An access port is hinged on the lid, making periodic inspection and maintenance of the roots without disassembling the entire structure possible. 4.
Markers placed on the container aid in monitoring set growth rates, while also providing an early indication of possible escapes. (Yes, I mark the container with lines to monitor expansion of roots. No, Dave is not going to stop making fun of this.)
The most important revelation from my mint exploits was that aggressive plants can be cultivated using hydroponics, but only if they are enclosed physically in a manner that safeguards all possibilities of unrestricted growth.
It’s not enough to just separate roots; stems, runners, and growth habit must also be examined. This same method works with other aggressive herbs too. After successfully containing my mint, I applied the same methods to lemon balm (another family member mint that has similar traits), oregano (not as bad as mint, but certainly unapologetic), and even a hydroponic strawberry plant that was ambitiously sending out runners throughout my system.
My approach has not been smooth. My effort to contain hydroponic lemongrass, in the same manners as the rest, turned out poorly. The plant’s root system was so vigorous that the pod cracked from within, like some sort of alien-plant chest burster. There are some plants, I’ve now realized, that simply can’t be tamed without a dedicated system.
Dave, who has been witnessing the entire saga with increasing humor, now calls my setup “Plant Alcatraz.” With containment pods, fences, and surveillance systems meant to track the plants, the title is not off. For other hydroponic dare devils out there looking into planting aggressive plants into their systems, I discovered these the hard way:
My number one core principle is that the plant ecosystem should not be underestimated no matter the species.
What may seem like adequate containment probably isn’t. Assume the plant will exploit any weakness when you design barriers. Second, transparency is your friend.
Being able to see root growth physically permits more efficient intervention prior to a breach occurring. Clear containers with routine observation have mitigated innumerable mint jailbreaks in my system. Third, removal from an area is far more efficient than containment. Rather, achieving better results allows for less stress, both on the plants and you.
It is easier to allow plants to grow in distinct, but adjacent, environments than trying to control their growth within a common system. Fourth, regularly scheduled harvesting helps. There is a positive correlation between aggressive top growth and aggressive root growth.
If harvesting mint leaves frequently (at least weekly) can help reduce its expansionist tendencies while also increasing the mint’s leaf production, then so be it. Finally, accepting defeat is the solution. Some combinations of plants are simply hydroponically incompatible, no matter how sophisticated the containment systems are.
If you find yourself constantly battling a plant that refuses to comply within a set area, think about whether dedicating one’s own system would infuriate the user, but ultimately provide more satisfaction. In spite of all these hurdles, I’m learning to appreciate mint’s indomitable vitality. That a plant so intent on growing actually has the resolve to circumvent any war I design is somewhat admirable.
As a person who appreciates nature (calathea), there are signs of hope with plants such as mints that seem to be thriving despite human interference. Ironically, last month, during my routine check-up of the hydroponic systems located in the building’s communal garden, I was met with a small mint plant situated right underneath my checking point.
Learning about plants trying to dominate each other is new to me; hence I just couldn’t get myself to remove the plant. In fact, I’ve tried adding more herbs like chocolate mints into the fray. My hypothesis is that with time and enough resources—chocolate mints may attempt to grow at an unprecedented rate.
Now my concern is for mints winning over something that’s entirely harmless right now: my basil.
