With the power of hydroponics, you can grow virtually any crop imaginable. But hydroponics refers to a general horticultural principle, not a specific type of system. Depending on what you want to grow, different systems have pros and cons.
There are many systems, rigs, and contraptions that feed nutrients to plants through a water solution and then recirculate the water to prevent waste and runoff. Within this general field, there are two broad categories of systems that cover just about everything: Leaf Crop systems, and Vine Crop systems.
The Difference Between Leaf Crops and Vine Crops
Leaf crops are plants that are grown solely for their vegetation. With lettuce and culinary herbs, you don’t need a plant to grow flowers, fruit, or seeds, you just eat the leaves! On the other hand, Vine Crops, or fruiting crops, are plants that go through multiple growth stages – first the vegetation develops, second they begin to bear the desired product.
Although Leaf Crops have one growth stage and Vine Crops have two, this fact, in and of itself, is not the reason that different types of systems are needed. The reason for needing different systems is the size of the plants.
Different Systems for Different Goals
Leaf Crop systems are for plants that are small and fast growing. They grow through the vegetative portion of their life and are harvested. A system for growing these plants doesn’t need the physical ability to hold large, heavy plants. This allows systems to be designed ergonomically, at table height, not on the floor.
Vine Crop systems are physically larger. Each vegetative plant will produce multiple products, be that tomatoes and cucumbers, or even roses, or cannabis. Systems that hold these plants usually start closer to the ground so that the plant maintenance is more easily in reach.
Within the category of Leaf Crop systems, there are many options to choose from. AmHydro is known around the world as a pioneer for our best-in-class NFT (Nutrient Film Technique) systems. These are systems with gently-sloping channels where nutrient solution runs end to end through the roots of plants. Beyond NFT, there are also Pond (or Deep Water Culture) systems where plants are floated on top of a pool of slowly-recirculating solution. Finally, Aeroponic systems also fit in here. These systems distribute nutrients and water via a fine mist sprayed onto plants.
As for Vine Crop systems, the most common is Container (or “Dutch Bucket”) systems. This is what AmHydro sells. The containers can be almost anything, with loads of DIY options, from Home Depot paint buckets to heavy plastic bags. The important thing is that these containers feed, at the bottom, into a pipe that recycles any leftover water. Additionally there is the Hanging Gutter system – where bags of growing medium are set on top of a gutter that catches dripping, leftover water from a wider area. The common feature in all Vine Crop systems is that there is a contained area for large plant roots to receive nutrients.
In all of these systems, the basic technique is similar: Feed nutrients to plants that circulate and capture waste water.
Putting this information to work
With this major difference between types of plants, it creates a big decision for a grower who is trying to build a successful farm. In this final section, we’ll try to answer some important questions to help you optimize your operation.
Some might wonder, if the basic principle is the same, why don’t we just have bigger NFT systems for vine crops? Or even the same size? And the truth is, this actually was a standard approach several decades ago, in the 1960’s and 70s. The problem is that root systems for Vine Crops can get very, very large. Unlike Leaf Crops, which are harvested after just 6 weeks, Vines have a life cycle of anywhere from 8-18 months. During that time, the roots do not stop growing! They can very easily clog channels, even extra-wide ones. Containers serve to constrain roots.
Another common question is: Do you need different nutrients for these different kinds of crops or can you feed all of your plants the same solution, from a single tank? Theoretically you can use the same nutrients, but that’s not recommended. The nutritional requirements of adult, flowering plants are different from young leafy plants. Different solutions help to maximize productivity.
Is one more profitable than the other? There’s no right answer to this, because the truth is based on several factors. What specific plant are you producing? What is your market is like? What price point are you able to sell at? In a sense, you are almost literally comparing apples to oranges. That said, while there’s no correlation between category and profitability, we usually do recommend most people start with leaf crops. They’re easier to manage, easier to sell at an entry level, they higher crop turn rate (meaning that failed crops can be replaced more quickly), and they ultimately require less work.
That’s another important point. Vine crops require more work. Unlike leafy greens, which simply grow up in system without need for maintenance. Vines require regular upkeep in the form of pruning, clipping, lowering, and more. This work must be performed for many weeks before you’re ready to harvest. Still, in many markets, it can be just as profitable, or more!
The final decision
With all this information and science, it is important to stress to growers that crop and equipment decisions should NOT be based on emotional criteria.
We regularly speak with aspiring farmers that are looking to get started because they feel strongly attached to the idea of growing a specific type of crop. This can often be a recipe for failure. It is a wonderful trait to have a desire to grow clean food for your community, but the decision to do that needs to be based on the actual needs of the community.
There’s an old trope about the neighbor who is trying to give away wheelbarrows of zucchini because their backyard garden overproduced. They just keep dropping off more and more zucchini until the neighborhood is sick of it. You need to avoid being that grower at all costs!
On the other hand, if you put value on identifying local market demand, and not just personal growing desire, you will have much better chances of making it in the long run. Good luck!