The humble potatoes is the most important vegetable crop in the world. Only rice and wheat feed more people globally each year. It’s also a crop that’s more often than not grown in soil, from massive agricultural plantings to the humble home veggie patch. But if you’re up for a challenge and have the space to spare, potatoes can thrive in the right type of hydroponic system.
Like hydroponic carrots they have a few very specific requirements that must be met, but with diligence and a bit of hard work you too can be dining on delicious potatoes grown right in your own hydroponic garden.
Can Potatoes Be Grown Hydroponically?
Yes, it’s possible to grow potatoes in hydroponic systems. They are such a vital crop that researchers have put in a substantial effort to learn the exactly what hydroponic potatoes require to thrive. NASA scientists are especially dedicated to growing plants, including potatoes, in hydroponic growing systems so they can be feed astronauts and space explorers on long term missions.
Much of what we know about what hydroponic potatoes need comes from these studies. This means that the humble home grower is intimately connected to one of humanities greatest ventures through the humble spud
“NFT and aeroponics are now used by “seed” potato growers in different areas around the world to produce disease-free potato planting stock. The technology we’ve developed by living in space and exploring our solar system and universe returns benefits every day to people around the world.”
Dr. Raymond Wheeler, plant physiologist, NASA Exploration Research and Technology.
The Secret to Hydroponic Potato Growing
The secret to growing hydroponic potatoes is understanding their strengths and vulnerabilities – and not mistaking one for the other!
Even small potato cultivars want a lot of room. They have large, sail-like leaves that sprout from long elegant vines, and a massive root system to match. You need to be ready to embrace that and give them a grow bed to accommodate the whole huge plant and root system.
They’re also moisture sensitive. You can’t let a crop of potatoes be submerged or kept in a sodden system or they simply rot away. This makes them an excellent candidate for precision drip systems that use very little water. Get the balance right and you’ll have a water efficient system capable of producing a long harvest of delicious vegetables.
|Hydroponic Setup Requirements For Potatoes
|14-16 hours bright broad spectrum light
|Loose, with good aeration and low water holding. Perlite, sand, vermiculite or peat blends.
|EC between 1.5 and 2.0; provide supplemental potassium
|Do not prune.
|1-2 plants per square foot; do not overcrowd.
|65 – 75°F
|Potato beetles, aphids
What is the hydroponic system for potatoes ?
Drip Hydroponic System
Spuds will grow wonderfully in large containers fed with a drip system. It’s easy to choose a bag or bin large enough for your variety and the space you have available. It’s very water wise, too. They’ll thrive on less water than you’d think in these systems, and a careful grower can make potatoes work with very little input.
Nutrient Film Technique
Nutrient Film setup will give you a surprisingly rich harvest if you give the roots room to spread. It’s a common technique for growing seed potatoes and adapts easily for the home grower. The dry conditions above the film support the development of healthy tubers. Make sure your setup has enough space for leaves and roots to spread for best results.
What is the worst type of hydroponics system for potatoes?
Potatoes struggle in consistently moist growing environments. Wicking beds and Deep Water Culture setups are simply too soggy and inevitably lead to disease. The notorious potato blight that contributed to the Irish Potato Famine is a form of Phytophthora that loves wet conditions. These type of growing systems set you up for disease and disaster.
Best Potato Varieties For Hydroponic Systems
The best potatoes are ones you enjoy eating. You can grow common supermarket potatoes in a hydroponic setup with little issue. Expect your crop of hydroponically grown potatoes to be smaller but they will taste pretty much the same.
Fingerling potatoes produce compact tubers that make it ideal for hydroponics. The Bellanita is an early maturing variety that will be ready for the table in around two months.
Norland is another early harvest that’s ready to go around 70 days after planting. It has a waxy red skin and good disease resistance. Yukon Gold is similar yellow early harvest spud.
How do I prepare Seed Potatoes from a Tuber?
Potatoes grow from a small tuber known as a ‘seed potato’. They’re smaller potatoes cultivated expressly for home growers to plant and harvest. They are checked for disease and provide predictable results.
But potatoes have miraculous properties, and one of them is that they’ll grow from a cut-off chunk of grocery-store potato. A whole potato with several eyes can be cut into many starters. You can also use this tactic to cut large seed potatoes into pieces and produce more plants per seed.
Simply slice each eye from the potato, allowing an inch or so (2.5cm) of clearance around the sprout itself. Place the seed pieces in a cool, dry place overnight and by morning it will be ready to plant.
How to Grow Hydroponic Potatoes
This method is the best home scale hydroponic system for growing potatoes in perlite. It was developed by the University of Florida’s excellent Institute of Food and Agricultural Sciences as a simple hydroponic system for growing potatoes. It’s also very light on equipment – you don’t need an EC meter, aeration stones or any other power. Just pop it in the sun and away you go!
For this technique, you will need:
- A large plastic container at least ten inches deep
- Seed potatoes or prepared cuttings
- 20-20-20 fertilizer with micronutrients
- 10-10-20 soluble fertilizer
Prepare your container. Drill a line of holes in each side of the container two inches (4cm) from the base and the same distance apart. This will allow a two inch deep reserve of nutrient solution in the bottom of the container, but still provide adequate drainage.
Place the container in your grow location and fill it with clean perlite, allowing an inch (2.5cm) of space at the top. Be sure to account for drainage. If growing indoors place it above a large enough tray to catch and drain excess solution.
For those cultivating their potatoes outside, be sure to place it in an area that receives at least 6 hours a day bright sunlight.
Add plain water to the container until the medium is thoroughly soaked. If growing indoors, add your grow lights.
Plant your whole seed potatoes directly into the growing medium at a depth of one inch (2.5cm) and four to six inches (10-15cm) apart. If using prepared cuttings, plant the seed pieces in the perlite with the cut side down and the eye facing up.
It will take around two weeks for the potatoes to grow their first shoots. Until then, water the seed potatoes every few days to keep the perlite wet.
Once the shoots appear add liquid fertilizer. Dilute 1 teaspoon of water soluble 20-20-20 fertilizer in a gallon of water. Pour in the fertilizer solution evenly through the perlite until it flows from the drainage holes.
Keep the perlite damp but not wet, watering around every 3 to 5 days. Alternate pure water or nutrient blend until the shoots are 18inches ( 45cm) in height, then switch to a 10-10-20 fertilizer solution to promote tubers.
It takes 70 days or so for the tubers to reach an edible size. They can be harvested early as “chats”. The plant itself will start to die off above the surface when the crop is ready to harvest.
To harvest your potatoes, remove them from the perlite, rinse and allow them to dry. Excess plant material can be composted or otherwise disposed of. The absence of dirt makes this system the easiest harvest of all potato cultivation methods. No digging required!
Potatoes will thrive under at least six hours a day of bright sunlight, or 10-12 hours of broad spectrum light from a grow light setup. Don’t exceed that photoperiod, as it results in smaller tubers.
To prevent disease, keep your water mildly acidic. A lower pH will prevent many of the fungal issues that plague root crops in hydroponic setups. Aim for a pH between 5.8 and 6.2
The preferred growing medium for the home grower is perlite. Once you get the hang of spuds in hydro you can branch out into other material. An equal mix of perlite, vermiculite and an organic like peat or coco coir is common in commercial cultivation. Seed potatoes are often grown in hydroponic systems with sand, too.
Potatoes are a potassium hungry crop so be sure to supplement. They will also go mad for leaves if your electrical conductivity creeps too high.
In general, to promote good tuber production aim for an EC of between 1.5 and 2.0, with a dose of extra potassium after the plants reach a foot and a half (45cm) in height.
Avoid pruning your potato vines. The more leaves you allow the plants to grow the better your crop will be.
Aim for no more than two plants per square foot. This will prevent disease and boost yields.
Potatoes prefer a cooler environment. They’ll do best between 65 – 75°F (18 – 24°C) with the biggest tubers at around 68°F (20°C).
When growing outdoors, watch out for beetles and leaf hoppers. Both can be controlled with insecticide sprays without much fuss.
If you’re growing inside your big villains are aphids. A tablespoon of Castille soap diluted in a gallon of water, works well to control them when applied as a leaf spray.
Potatoes are prone to a bewildering array of tuber diseases. Most can be dodged if you purchase certified seed potatoes from a local seed store. Practicing good hygiene and pest management helps too.
How Long Does It Take To Grow Potatoes Hydroponically?
Depending on your cultivar, you can expect to harvest the potatoes around 70-90 days after planting. This is typically a full month earlier than conventionally grown spuds. I personally enjoy the crisp texture and light flavor of young, ‘chat’ potatoes. These little wonders can be pulled from the rig as soon as they appear.
What is the Expected Yield from Hydroponic Potatoes ?
The yield when growing potatoes indoors largely depends on how much room you give them to spread out. A small tub will only have room for a small harvest, and a larger rig will give you more.
Can I put potato in water and it grow?
It’s a common elementary school experiment to put a potato in a vessel of water and watch its lovely vines grow. It’s not a viable way to grow a crop, however. The initial vines are fueled by the nutrients stored inside the potato, and without substantial fertilization it won’t be able to produce new tubers.
As a Canadian, harvesting fresh new potatoes when growing outside is impossible demonstrates the power of indoor growing. It’s a way to secure our ability to feed ourselves against the odds. Hydroponic potatoes may be one of the tougher choices, but the benefits of growing food where you eat it can’t be overstated. Potatoes are one of the critical foods, and hydroponics allows you to grow them anywhere, from the Great White North all the way to space and beyond!