How to Grow Cacti in Water and Key Points to Note

Growing cacti in water is a way of moving cacti from traditional soil cultivation to a clear-water environment. Cacti are naturally drought-tolerant and afraid of waterlogging, and the body stores a large amount of water, so with the right method they can also root and grow normally in water. After being grown in water, cacti are clean and tidy, are not prone to soil pests, and look very fresh placed on a desk or windowsill.

When first switching to water culture, it is advisable to deal with the root system first. Take the cactus body out of the pot, shake off the soil, cut off dead and rotten roots, and let the wounds dry in a cool, well-ventilated place. Then use the shallow-water rooting method to let the base of the body stay close to the water surface without being directly soaked. Once new roots grow, gradually let the roots enter the water. This can greatly reduce the risk of root rot.

In daily care, water level control is key. The water surface only needs to cover the lower half of the roots, and the base of the cactus body must remain above the water surface, keeping it dry and ventilated. As for water quality, tap water that has been left to stand for one or two days can be used. In summer, change the water every few days; in winter, the interval between water changes can be appropriately extended. If the water becomes cloudy or has an odor, change it immediately.

Light and temperature are equally important. Cacti grown in water like plenty of soft sunlight. Long-term shade will cause the body to become leggy and soft, while during periods of strong light in summer, appropriate shading is needed. When the temperature is low in winter, the plant enters dormancy and should be moved to a warm place, and the nutrient solution should be stopped. When the weather warms up the following year, a small amount of water-culture nutrient solution can be resumed.

The most common problems during care are root rot and green algae growth. Root rot is mostly caused by too high a water level, infrequent water changes, or lack of oxygen. If root rot is found, cut it off promptly and induce rooting again. Green algae can be suppressed by choosing opaque containers and changing the water frequently. By keeping the water clean, the cactus can remain in good condition for a long time.