You’ve probably heard of hydroponics before—the new-kid-on-the-block method of planting and growing all sorts of plants without soil. It’s a pretty neat concept, and people have used it to make flourishing businesses all over the world.
With all that said, is it possible to grow citrus trees hydroponically? Grapefruits, limes, lemons, oranges, etc.—will these trees thrive in an environment without a growing medium and nutrients injected straight to the roots? Let’s find out together.
What Is Hydroponics?
Hydroponics is basically a plant-growing technique that requires no soil at all. It may sound strange to the uninitiated, but there’s a method to this madness.
Hydroponic Methods
How hydroponics works depends on the type of method employed. Here’s a quick breakdown of the most common techniques growers use:
- Nutrient Film Technique (NFT): The roots of seedlings make contact with a continuous flow of a nutrient-rich solution. Usually, the plants sit in cups, with the bottom of the cups inserted into PVC pipes. A pump takes water from a basin and directs it inside the pipe. The water that drops out the other end of the pipe ends up in the basin, and the cycle continues.
- Deep Water Culture (DWC): Similar to NFT, the roots of seedlings are submerged in a nutrient-rich water. However, the seedlings are placed in cups or trays that float atop a body of the nutrient water. The roots are in constant contact with the water, so no pump is involved.
- Ebb and Flow: This technique is like intermittent DWC. The roots are submerged in the nutrient solution but not for extended periods. After a certain amount of time, the pool or basin holding the water is drained, which leaves the plant’s roots high and dry until the next artificial ‘flood.’
- Drip System: This method relies solely on a container or a farmer to administer nutrient-rich water directly to the plant at specific times. It’s great for reducing water consumption while also regulating how much or how little each plant receives. The downside is that it’s more hands-on than the other methods.
- Wick System: A wick is simply a piece of cloth that transfers water from one place to another. One end of the cloth is submerged in a nutrient solution, and the other end is placed near the roots of a plant. The solution will gradually saturate the wick and water the plant.
Pros of Hydroponics
There are several reasons why new-age farmers employ one or several hydroponics growing methods:
- Water Efficiency: Hydroponics methods can reduce water consumption by 90%. This is a major upside for those that live in drought-prone areas.
- Faster Growth: Some studies indicate that hydroponics accelerates growth rates by up to 50%. Faster growth rates means sinking your teeth into vegetables and fruits sooner.
- Higher Yields: Not only do plants grow quicker, but they might also produce greater yields at the end of the season. This is because the plants are placed in a controlled environment with nutrients injected straight to the roots.
- Year-Round Production: Some hydroponic farms can artificially regulate the environmental conditions. This may include using fans, heaters, or coolers inside a tent or other structure to alter the temperature. For example, if you make it cold enough, you can grow blueberries during any time of the year!
- Space-Saving: Hydroponic systems are designed in such a way to maximise floor and garden space. Usually, the plant holes in the PVC pipe are spaced 30 centimeters apart. Wider pipes can allow for 2 rows, thereby doubling the amount of plant holes.
- Reduced Risk of Pests and Diseases: Because no soil is thrown out of the equation, you don’t need to worry about soilborne pests or diseases plaguing your plants. Still, you need to be watchful of airborne pests—e.g., oriental fruit flies—from wreaking havoc.
- Little to No Weed Problems: Any gardener knows how pesky weeds are. They compete against our crops in drawing nutrients from the ground and soaking up all the sunrays. With a hydroponics system, you don’t have to worry about weed problems as much with simple sanitation practices in place.
Cons of Hydroponics
As great as hydroponics is, there are a few downsides new gardeners should be aware of:
- High Startup Costs: Instead of dropping seeds into the soil, you will need to purchase all sorts of equipment. This includes PVC pipes, buckets, basins/reservoirs, TDS/EC metres (to measure the amount of nutrients in PPM), pumps, rockwool, net pots, grow lights, and so on. While costs per item are relatively low, they add up to quite a bit.
- Reliance on Electricity: Certain hydroponics systems rely on electricity to keep the nutrient-solution flowing. If the lights go off, you’ll need to find another way to keep the water moving.
- Constant Monitoring: Anything can go wrong at any moment (read the previous point). It’s your duty as a hydroponics gardener to ensure everything is in control. This includes monitoring nutrient levels, pH levels, and water conditions.
- Waterborne Diseases: While soilborne diseases are kept at bay, the risk of your plants contracting a waterborne illness Contaminated water sources or equipment can infect the entire system.
What Does a Citrus Tree Need to Grow?
If you’re on the East Coast and want to grow a citrus tree in your backyard, there’s no better time than the present! But before choose a citrus tree, you first need to determine whether or not your garden can support growth:
1. Optimal Climate and Sunlight
Citrus trees originated from subtropical and tropical regions, so they thrive in warm and sunny climates. They need between 6 to 8 hours of sunlight per day. In cooler areas, you can start growing them in indoor containers before moving them out when the temperatures rise. The ideal temperature for growing citrus fruit trees is between 13 and 35°.
2. Water and Humidity
Citrus trees require regular watering to maintain moisture. Ideally, you will use well-draining soil to prevent the base from becoming waterlogged, reducing the risk of root rot. Citrus trees prefer humid environments, which can be a challenge for areas with little to no rain.
3. Nutrient Requirements
Citrus trees require tons of nutrients, such as NPK, magnesium, zinc, and iron. Like any fruit tree, citrus trees require special care and attention during active growth periods, where the trees are ready to bear fruits.
4. Pruning Needs
All fruit trees, including citrus trees, need a trim every so often. Pruning is done not just to give the tree an eye-pleasing shape, but it also improves fruit production by getting rid of dead weight. Imagine redirecting nutrients from a dying branch to one that’s healthy—this is what pruning does for your tree.
Can You Grow Citrus Trees Hydroponically?
After researching your area and concluding the feasibility of growing citrus trees, you might be wondering: “Can I grow citrus trees hydroponically?” Well, the answer isn’t so simple.
It’s true that hydroponics systems can support growing fruit trees of any variety. The main problem with growing citrus trees hydroponically is whether or not the net cup or an alternative container can support the weight of the tree.
The longer the tree grows, the heavier it becomes. Even dwarf fruit trees, which are much smaller than traditional trees, can be too heavy for even the largest net cup.
With all that said, there’s certainly no problem trying to grow a citrus tree hydroponically for the first year of its life. After the tree becomes too large, you’ll need to transplant it to a large pot or into the soil for better development.
Alternative Plants to Grow Hydroponically
Suppose you already invested in a hydroponics system. Well, what can you do now after learning that citrus trees aren’t the ideal plant to grow hydroponically? The good news is, there’s no shortage of crop varieties you can grow in a hydroponics system!
1. Leafy Greens
Leafy greens like lettuce, spinach, kale, and arugula are among the easiest and most rewarding plants to grow hydroponically. These plants have short growth cycles, high yield potentials, and can be harvested multiple times from the same plant.
They thrive in cooler temperatures and lower light conditions compared to fruiting plants, making them ideal for indoor setups. The NFT or DWC systems are particularly effective for these types of greens.
2. Herbs
Common herbs such as basil, mint, cilantro, and parsley are perfect for hydroponic cultivation. These herbs are frequently used in cooking and can be quite expensive to buy fresh in stores.
Herbs generally require similar conditions to leafy greens and benefit from constant access to water and nutrients in a hydroponic system. They can be grown compactly, making efficient use of space.
3. Tomatoes
Hydroponic systems are excellent for growing various types of tomatoes, including cherry, beefsteak, and heirloom varieties. Tomatoes are particularly well-suited to more advanced hydroponic setups due to their need for support as they grow.
Tomatoes need ample light (5-7 hours of direct light per day) and warm temperatures. They thrive in systems like drip systems or ebb and flow, which support their heavy nutrient and water needs.
4. Tamarillos
Also known as tree tomatoes, tamarillos are an exotic fruit that adapts well to hydroponic systems. They produce small, egg-shaped fruits that are rich in vitamins and antioxidants.
Tamarillos require a lot of light and prefer a temperature range of 15 to 24°. They are suitable for systems like the Dutch bucket system, which can support their taller growth and heavier fruiting branches.
5. Strawberries
Strawberries can be grown hydroponically, yielding fruits that are often more flavorful and less prone to pest issues than their soil-grown counterparts. They are suitable for vertical hydroponic systems, optimising space usage.
Strawberries require full sunlight and cooler temperatures than many other fruits. A drip system or an NFT system can be effective, allowing easy access to nutrients and water while preventing issues like rot and fungus.
6. Cucumbers
Suitable for hydroponic growing, cucumbers can produce high yields when given adequate space to develop. They are commonly grown in vertical hydroponic systems.
Cucumbers need a lot of light and warm conditions. They do well in systems that support vine growth, such as trellis-supported setups in DWC or ebb and flow systems.
