Once established, Mount Diablo manzanita is highly drought-tolerant. Water deeply but infrequently during its first year to help it establish.

After that, minimal supplemental watering is needed, especially in its native habitat. Overwatering can lead to root rot, so ensure excellent drainage.

Prune lightly after flowering to shape the plant and remove any dead or damaged branches. Avoid heavy pruning, as manzanitas have slow growth and can be sensitive to excessive cutting.

Focus on maintaining a natural form and good air circulation.

Propagation is typically done from seeds or cuttings. Seeds require a period of cold stratification to germinate. Cuttings should be taken from semi-hardwood in late summer or early fall.

Success rates can vary, and patience is key for establishing new plants.

Repotting is rarely necessary for mature plants as they prefer to remain undisturbed. If transplanting a young plant, do so with extreme care to minimize root disturbance.

Ensure the new location has excellent drainage, mimicking its native rocky or sandy habitats.