Choose plants that suit passive Kratky hydroponics, from lettuce and herbs to crops that need larger reservoirs and more careful management.
Best Kratky plants
Lettuce, basil and other compact leafy greens are among the easiest Kratky crops. They grow quickly, need modest support and can often complete a crop cycle in a reasonably sized container.
Why leafy crops are easier
Leafy crops generally have a shorter growing period and lower total water demand than large fruiting plants. That makes it easier to size the reservoir so the plant can grow without constant intervention.
More demanding crops
Tomatoes, cucumbers and peppers can be attempted in passive systems, but they need much larger reservoirs, stronger support and closer attention as water and nutrient demand rises.
Match plant to container
Container volume matters as much as crop choice. A small herb may tolerate a modest jar, while a large or long-season plant needs substantially more solution and physical stability.
FAQ
Does Kratky need an air pump?
No. A conventional Kratky setup is passive and relies on the air space above the nutrient solution. If you add continuous aeration, the system is operating more like DWC.
Should I keep topping up the reservoir?
It depends on crop duration and container size. For longer crops, topping up may be needed, but preserve an air gap around the upper roots rather than restoring the original full level.
