While you can grow almost anything hydroponically with customized equipment, root vegetables (like potatoes, carrots, and onions), large trees, and vining plants with massive space needs (like pumpkins) are generally not grown. They either require deep, malleable soil to expand or are simply too large and heavy to support.
Root vegetables like carrots and beets and larger curds like cauliflower may be difficult to grow in a small hydroponic system and are better suited to a more elaborate setup. At Fork Farms, we recommend saving these for your outdoor gardens.
For starters, root vegetables such as potatoes, sweet potatoes, carrots, cassava, yams, horseradish, parsnips, taro, Daikon, rutabaga, salsify, Jerusalem artichokes, ginger, and turmeric cannot be grown using our hydroponic towers.
5 Disadvantages of Hydroponics
The most profitable hydroponic crops are fast-growing leafy greens, specialty herbs, and high-yield fruiting vegetables. Farmers maximize margins by targeting quick harvest cycles, high-density vertical planting, and consistent restaurant or premium market demand.
Tap water can be used but often contains chlorine, chloramine, and minerals that affect pH and plant health. Let tap water sit for 24 hours to off-gas chlorine, or use a dechlorinator. For best results, use filtered water or reverse osmosis (RO) water and add nutrients from a clean baseline.
The fastest-growing hydroponic plants are leafy greens and specific herbs, which can go from seed or seedling to harvest in just 2 to 4 weeks. Because they do not need to flower or fruit to be edible, they are hyper-efficient in water-based nutrient systems.
Since hydroponics do not use soil, many traditional organic growers feel that they are not eligible. If people want to see the organic certification sticker on their fruit or vegetable, they will not be able to do so at this time on produce that is grown hydroponically.
For most standard hydroponic systems, you should perform a full water change and clean the reservoir every 10 to 14 days. This schedule prevents nutrient imbalances, salt buildup, and harmful root diseases.
3 Types Of Plants To Avoid Growing In Your Hydroponic Farm
While growing plants in a hydroponic system helps reducing the risk of soil-borne diseases, the continuous circulation of water through the system puts the plants at risk of contracting some waterborne diseases. Sometimes, these diseases are carried by the water solution from one plant to the rest.
The best indoor hydroponic plants are fast-growing, shallow-rooted, and highly productive. Leafy greens and herbs thrive best, specifically lettuce, basil, spinach, and mint. They yield rapid harvests and require minimal space. For decorative spaces, hardy water-friendly houseplants like pothos, spider plants, and lucky bamboo are excellent choices.
The lifespan of hydroponic plants depends primarily on the plant species and how you maintain your system. While leafy greens last 1 to 2 months, herbs can thrive for several months, and fruiting crops can remain productive for 6 to 18 months or longer.
Standard water-soluble Miracle-Gro is generally not recommended for hydroponics. It is formulated for soil, meaning it lacks vital micronutrients and often relies on urea nitrogen, which cannot be broken down without soil microbes and can quickly cause toxic root rot in hydroponic systems.
Leafy greens such as arugula, butterhead lettuce, collard greens, herbs, kale, mustard greens, microgreens, spinach, and swiss chard are suitable crops for hydroponics. They have shown good performance in NFT systems.
Cons
Although city water treated by municipalities must meet the minimum EPA standards, well water is not regulated and can also contain harmful contaminants like chromium, arsenic, or bacteria. While city or well water may meet drinking water standards, it may not be ideal for plants or hydroponics.
Timing makes a big difference to how effectively plants use water.
Hydroponic plants grow 30–50% faster than soil-grown plants and use up to 95% less water. Soil gardening offers lower startup costs and a more intuitive growing experience for beginners starting outdoors. Hydroponic systems eliminate soil-borne pests and diseases, reducing the need for pesticides.
Mistake: Assuming plants will grow well without proper temperature or humidity management. Plants grown in hydroponics are sensitive to heat, light, and humidity. In hot and humid areas, failure to manage temperature can lead to plant stress, algae growth, and fungal infections.
Lavender has a reputation. It's calming, aromatic, endlessly useful, and adaptable to soil-free cultivation. Growing hydroponic lavender indoors gives you precision, consistency, and year-round harvests with fragrance that hits you the moment you approach the grow area.
The name “century plant” comes from the fact that the slow-growing plant takes years — although not 100 — to flower. The century plant, Agave Americana, is monocarpic, meaning it will bloom once in its lifetime. That bloom may not appear for 10, 20 or more years.
Saffron: The Most Profitable Crop per Acre
Dubbed "red gold", saffron's high market value makes it arguably the most profitable agricultural crop. Though it requires careful cultivation, the potential profits per acre are unmatched, highlighting its viability for small farms looking to maximize their earnings.
You can grow and harvest several fast-maturing vegetables in 30 days or less. These are mostly leafy greens and quick-rooting crops, ideal for early spring or fall planting.