Haworthia need to be watered when their soil is completely dried out and their leaves start to curl (about every two to three weeks). In the winter, they need less water, so you can basically forget about them and just water them every other month. Light: Haworthia love bright, indirect sun
Haworthias prefer an acidic growing medium. However, low pH makes the conversion of urea to Nitrogen usable by plants slow. It is recommended to use synthetic fertilizers because they dissolve in water and in most cases, are available for immediate uptake. This allows the nutrient supply to be accurately controlled.
Although some Haworthia species can be found in full, bright sun, many live in more protected spots and therefore are adapted to thrive in partial shade (though few look their best without at least some direct sun or bright light). This makes Haworthias well adapted to lower light conditions found in homes.
They do best in the temperature range of 75-90°F. But they can tolerate temperatures into the low 40ºFs, especially if they do not have continuously wet soil and they will survive high temperatures into the low 100ºFs, especially if they are somewhat shaded and have good air movement.
Repot haworthias every two to three years to freshen their soil, or whenever they spread to within 1/4 inch of their container's edge. Avoid frequent transplanting since haworthias do not respond well to root disturbance.