Growing without soil
How can a plant grow with no soil at all?
This plant has no dirt anywhere. Its roots hang in a tub of water.
No soil? Then where does it get its food?
Think about dinner. You could search a whole kitchen for something to eat.
Or someone could bring a plate right to you.
Roots in soil have to search. They grow out far to find water and food.
In water, the meal comes right to the roots.
You can grow a plant in water with plant food mixed in. It needs no soil.
This way of growing is called hydroponicsGrowing plants in water with plant food mixed in, and no soil.
See it in the glossary.
Soil does more than feed a plant. It holds the plant up and keeps water and air near the roots.
So who does those jobs now?
A small cup full of holes holds the plant up in the lid. The roots grow out through the holes.
The cup is called a net potA small cup full of holes that holds a plant up. Roots grow out through the holes.
See it in the glossary.
The water sits in a tub under the plant. Growers mix plant food into it.
The tub is called a reservoirThe tub that holds the water and plant food.
See it in the glossary.
Roots need air, too. In soil, air fills tiny gaps between the bits.
In a tub, a pump blows bubbles into the water to bring air.
Your turn. Who does soil’s jobs now?
Match each job to the letter of the part that does it.
Match each job to a letter.
- A · net pot
- B · water with plant food
- C · air stone
- D · air pump
Tap a letter, then tap its name.
Which name goes with A?
Match each job to a letter.
- A · net pot
- B · water with plant food
- C · air stone
- D · air pump
The answer:
- A · Holds the plant up The net pot holds the stem, the way soil did.
- B · Brings water and food The plant food is mixed right into the water.
- C · Puts air in the water Bubbles from the stone carry air to the roots.
- D · Pushes air down the tube The air pump pushes air down the tube to the stone.
Check 1 of 3
What is hydroponics?
Show the answer
Growing plants in water with plant food, and no soil. Right. The water brings the food straight to the roots.
Check 2 of 3
There is no soil. What holds the plant up?
Show the answer
A net pot. Right. The cup holds the stem, and the roots grow through its holes.
Check 3 of 3
Why does a tub of water need bubbles?
Show the answer
Roots need air to stay healthy. Right. In soil, air sits in tiny gaps. In water, bubbles bring it.
You just learned how plants grow without soil.
Next up: Six ways to do it.
Go deeper: soil's jobs, done another wayOpenClose
The word hydroponics comes from two Greek words, one meaning water and one meaning work or labor.
Scientists grew plants in water long before it was a way to farm. They used it to learn which nutrients plants need.
In the 1920s and 1930s, a California plant scientist named William Gericke made the word known. He turned the lab method into a way to grow crops.
In soil, nutrients cling to tiny bits of soil and pass into the water around roots. In hydroponics, the grower dissolves them in the water on purpose.
Soil also acts as a buffer that keeps pH and nutrient strength steady. Without it, problems show up faster, so hydroponic growers test their water often.
Many systems hold plants in a growing medium, such as coconut fiber, rock wool, or clay pebbles. The medium holds the plant up and holds water. Most media add little or no plant food.
Sources
- Dunn, B. Hydroponics. Fact sheet HLA-6442. Oklahoma State University Extension, 2025. Link
- Nelson, M., G. Langellotto, and L. Nackley. Hydro hints: What is hydroponics? EM 9453. Oregon State University Extension Service, 2025. Link
- Hart, C. Home Hydroponics (handouts). University of Illinois Extension. Link
- Gatiboni, L. "1. Soils & Plant Nutrients." In Moore, K. A., and L. K. Bradley, eds. North Carolina Extension Gardener Handbook, 2nd ed. NC State Extension, AG-831, 2022. Link
- Accessible Gardening: Hydroponic Gardening. Green Thumbs, Healthy Joints, West Virginia University, 2011. Link
- Kratky, B. A. Three non-circulating hydroponic methods for growing lettuce. Acta Horticulturae 843: 65-72, 2009. Copy hosted by the University of Hawaii CTAHR. Link
- Hoagland, D. R., and D. I. Arnon. The Water-Culture Method for Growing Plants without Soil. Circular 347. University of California College of Agriculture, Agricultural Experiment Station, 1938. Link
- Singh, H., and B. Dunn. Electrical Conductivity and pH Guide for Hydroponics. Fact sheet HLA-6722. Oklahoma State University Extension, 2017. Link
- Johnson, K. Growing without soil: Getting started with hydroponics at home. Good Growing blog, University of Illinois Extension, 2026. Link