INTRODUCTION:  This is a large family of succulents, many being native to the drier parts of the world.  They are dicots and produce clusters of showy, small flowers.  Many of these succulents require much water during their growing season but then little or none when they are in rest. 
 The genus Crassula has many popular house plants.  They range from small shrub-like forms to trailing types.  Jade plant is popular member of the genus.  Although the solid green form is common, there are many interesting variegated patterns.  Although they may have descriptive common names, such as propeller plant, silver beads, scarlet paintbrush, string ‘o buttons, etc., many are simply called for the name of the genus, crassula. 
 Many species in the genus Echveria are ornamental.  They have very short internodes and rosettes of leaves.  The plants bear tubular flowers on long inflorescences, usually in the winter.  Many go by the common name echeveria. 
 Kalanchoe is a large genus with many species used as houseplants.  Kalanchoe blossfeldiana is a common potted flowering plant which is easy to maintain and bring into bloom during short day periods each year.  Older forms are large with tall inflorescences of red flowers.   Smaller forms with a wide range of colors are more common today.  This plant is commonly called kalanchoeKalanchoe tomentosa has small fleshy leaves covered with white fuzz and brown tips which give it the common name panda plant.  Several kalanchoes, such as Kalanchoe pinnata,  Kalanchoe uniflora and Kalanchoe tubiflora, air plant or walking kalanchoe, produce small plantlets at the edges of their leaves. 
 The genus Sedum also has many popular succulent houseplants.  Sedum morganianum, the burro’s tail, has trailing stems with small, succulent, bluish, pointed succulent leaves.  Sedum bryophyllum has a distinct, moss-like appearance.
General Care of Crassulas:  


temperature: Average house temperature is best for most members of the family.  Some benefit from a cool spell, usually during the winter.
medium: Succulent mix with good drainage.  Clay pots are better than plastic since the added weight helps to balance the top weight of many of these plants.
water: Water thoroughly, being sure that the water penetrates the medium from top to bottom.  Allow the medium to dry somewhat between waterings.
light: Sunny to semi-sunny location is best.  Bright light indoors improves vigor and appearance.  Many need short days (long nights) to initiate flowers.
fertilization: Avoid high nitrogen fertilizers, using a 1:1:1 analysis.  Fertilize during the growth period but withhold fertilizer during the slow growth or rest periods that many of these plants go through.
pests and problems: Overwatering or a wet medium is the most likely cause for problems.  Excessive use  
of  fertilizer can also cause weak plants.
grooming: Remove excess plants from the pots of those that produce little plantlets on the edges of their leaves.  Remove dead, dried leaves.  Plants usually
propagation: Stem cuttings and leaf cuttings are the most common propagules.


Virtual Garden's Directory of Foliage House Plants