How to Grow Gasteria
If you're like most gardeners growing your gasteria indoors, choose a spot that gets a lot of light but not direct sunlight. And if you live in USDA hardiness zones 9 to 11 and wish to plant your gasteria in the garden, select a site that has dappled sunlight, such as beneath a large tree. Moreover, indoor potted gasteria plants can be brought outdoors and placed in a lightly shaded area for the summer.
Be aware that the plants don't react well to water falling directly on the leaves, so provide them with some shelter from rainfall and sprinkler systems if possible. Otherwise, the leaves might start to rot. Likewise, excellent drainage both from the soil and the planting container is key to growing healthy gasteria plants.
For container plantings, use a cactus potting mix or another fast-draining potting soil mixed with a few handfuls of sand. For garden plantings, somewhat sandy soils are best to provide sufficient drainage
Fertilize once every spring with a cactus fertilizer. Gasteria plants like a bit more organic matter in their soil than most succulents do, so mixing in a bit of compost at the time of planting can be a good idea.
Potting and Repotting
When potting your gasteria, choose a container that has ample drainage holes. Many gardeners prefer unglazed terra cotta pots, which allow soil moisture to evaporate through their walls. This helps to prevent rot issues from overwatering. Also, opt for a shallow and wide container over a deep and narrow one, as these plants grow shallow roots.