Take note that some succulent varieties are naturally more active and grow in the winter season, and some become dormant during the summer months. Crassula Obvata Crosby's Dwarf’ may still experience sunburn if exposed to the sun during a heatwave and when it gets extremely hot in summer. Even though they can be visually unattractive, sunburn brown spots can actually cause damage to the plant. Avoid leaves with discolorations, spots or other marks. These leaves are native to South Africa or Mozambique. They are known for their fleshy, thick, shiny, smooth leaves.