Hydroponics Outdoors – 9 Tips for Maximum Yields
Indoor hydroponic gardens produce excellent yields, but they cost a small fortune to run and maintain. They require grow lights, humidifiers, air conditioning, and other climate control features that can run up monthly bills and make it difficult for the average farmer, gardener, or grower to recoup his or her investment. That’s why many gardeners are turning to outdoor hydroponic gardens instead.
Outdoor hydroponic gardens are more efficient than soil-based gardens but cheaper to manage than indoor hydroponic systems. They offer a perfect balance of nutrients but take advantage of natural sunlight to eliminate the costs associated with specialized grow lights. Like indoor systems, outdoor hydroponic systems require no weeding and are much less prone to insect damage than conventional gardens, and they can be scaled up easily as growers get the hang of outdoor gardening.
Want to jump on board with this new gardening trend? Don’t start buying plants or seeds just yet. Instead, read on to find nine tips for maximum yields first to get a feel for outdoor hydroponic gardening best practices.
1. Build It in the Sun
Arguably the largest benefit to outdoor hydroponic systems is that they don’t require grow lights. Instead, the plants can get all the light they need to photosynthesize and grow from the sun. It’s important to choose a location for the hydroponic garden that takes full advantage of natural sunlight to maximize yields.
Choose a spot with southern exposure, especially if the garden will be operational year-round. During the late fall through the early spring, the sun travels a path closer to the horizon so a south-facing slope will get far more light than a north-facing slope, or even flat land. It’s equally important to ensure that no tree cover, buildings, or other structures will shade the garden, so take down overhanging branches and nearby trees, especially those to the south of the garden, before setting up the system.
2. Keep the Water Cool
Keeping the water reservoir cool throughout the hottest months of summer will prevent wilting, reduce evaporation, and ensure maximum growth. This is especially important for growers in hot climates. The combination of direct sunlight, heat, and the lack of an enclosed space can lead to exorbitant water bills, and cooling the water is the easiest way to avoid this problem.
There are a few easy ways to go about keeping the water cool. Those looking for a low-maintenance solution can buy a water chiller designed for hydroponic systems. This is the most expensive option, but it’s also the most effective.
Growers working on a budget can also partially bury their reservoirs in the ground to insulate them, place them in shady spots away from direct sunlight on the north side of the garden, or toss frozen water bottles in the reservoir during hot days to keep it cool. It’s also fine to add cold water to the tank periodically, but this will alter the PH and EC of the water so it will require more frequent adjustments.
3. Lower the Electrical Conductivity (EC)
Plants need more water during the hottest days of summer, so growers should lower the EC of their nutrient solutions to make it easier to absorb. Plants in the vegetative stage should have an EC of around 1.3, as higher concentrations of nutrients can restrict growth. During the flowering and fruiting stages, the EC may need to be a little higher.
Outdoor hydroponic growers should pay careful attention to their plants, especially during the flowering and fruiting stages. If the nutrient concentrations in the water are too high, it can cause nutrient burns. Look for common signs of this problem like browning leaves and add more water as needed to alleviate the stress on the plants.
4. Prepare Plants for the Heat
Heat stress can stunt plants’ growth and reduce growers’ yields, but there are a few preventative steps that can be taken to avoid these problems. Cooling the water can help, but serious growers should take additional steps such as adding humic acid and liquid kelp to their nutrient solutions early in the season to prepare the plants for the hot days ahead.
Humic acid and kelp, applied in a 5:2 ratio, stimulates root growth, making it easier for plants to absorb the water they need to perform evapotranspiration and keep themselves cool on hot summer days. The extra nutrients also strengthen the plants, making them less susceptible to cell damage from heat stress and direct sunlight. Apply the humic acid and kelp in the spring as a preventative against heat stress later in the season, because there’s little growers can do about it once the full heat of summer is upon them.
4. Ensure Proper Air Movement
Sufficient air movement in the form of natural breezes helps to keep plants’ stomata open. Plants use their stomata, which look like microscopic openings in the leaves, to release excess water to keep themselves cool, absorb carbon dioxide to facilitate photosynthesis, and release oxygen as a byproduct. When the plants are stressed by stifling heat or lack of water, they may close their stomata to retain moisture, but a cool breeze will help them avoid stress and keep their stomata open.
Locating a garden in an area that gets plenty of airflow also ensures that water vapor can evaporate easily off of plants’ leaves. This also helps to keep them cool.
The other side of the coin is that heavy wind can damage the plants. The ideal location for an outdoor garden is one that gets gentle breezes but has protection against damaging winds.
5. Deter Pests
The best way to deter pests in an outdoor hydroponic garden is to ensure that the plants have everything they need to stay healthy and strong. That includes plenty of nutrients, a constant supply of water, and often some extra calcium to help the plants build stronger cell walls to keep pests from munching on their leaves, stems, fruit, and flowers. Healthy plants also produce tastier, more nutrient-dense fruits and brighter, showier flowers.
Even healthy plants may not be able to withstand serious insect infestations. When this is the case, gardeners will have to use insecticides or other products to deter pests. Aim for a least-toxic approach and start with organic pest sprays, insecticidal soaps, introducing beneficial insects to the garden, and only use toxic insecticides as needed to control serious infestations.
6. Choose the Right System
There are many types of hydroponic systems, but they’re not all ideal for outdoor setups. Avoid deep water culture systems, which won’t be as able to withstand temperature fluctuations. Top feed, aeroponics, or flood-and-drain systems are all better fits for outdoor gardens.
Growers who don’t have much space may want to consider vertical hydroponic systems. They have smaller footprints on the ground and allow gardeners to grow more plants, making vertical hydroponic systems perfect for rooftop gardens and small yards.
7. Invest in UV-Protected Equipment
Not all hydroponic equipment is designed for outdoor use. Indoor hydroponic equipment doesn’t have to hold up to UV exposure and inclement weather, so unless gardeners plan to implement their own measures for protecting it, it can degrade over time. When applicable, gardeners can construct outbuildings to protect critical system components that don’t need to be located directly next to the plants. They should also invest in UV-protected containers and buy hydroponic equipment that can withstand the elements, even if it means spending some extra money on the initial setup.
8. Monitor Plants and Conditions Closely
All gardens, whether hydroponic or soil-based, indoor or outdoor, should be monitored closely to ensure that the plants are getting everything they need to thrive. Since outdoor hydroponic gardens can produce crops three to four times faster than traditional soil-based gardens, growers who choose to use this method need to be particularly careful. Issues like extreme temperatures, improper nutrient concentrations, and insect attacks can all stunt plants’ growth and decrease yields so they need to be handled as soon as they come up.
9. Start Simple
Growers who are just trying their hands at hydroponic gardening for the first time should start with small, simple setups that can be scaled up easily as their knowledge and experience progress. Starting out on a small scale reduces the need for automation, helping to keep costs low, and makes it easier to monitor each plant’s health. As outdoor hydroponic gardeners get a feel for their systems, they can start scaling their operations up and investing in the sensors, controllers, pumps, aerators, and other equipment required to automate garden labor and increase yields.
The Bottom Line
Outdoor hydroponic gardening offers the best of both worlds. Hydroponically grown crops in a well-maintained system produce larger yields in shorter periods than soil-based crops, and outdoor systems require fewer external inputs than indoor hydroponic setups. If gardeners do their research in advance, purchase products from a reputable supplier, and pay close attention to their plants to ensure that they are getting all the nutrients, water, and supplements they need to grow and thrive, they should start seeing their investments pay off in just a few months.