Jade (Crassula Argentea)
by Tom Rood, Master Gardener
Cornell Cooperative Extension

Jade plants, succulents from South Africa named after the greenish gem stone, are probably one of the easiest house plants to grow. Succulents can store water in leaves, stems, and roots; a survival trait for drought periods encountered in nature and provides a hint on domestic care. This is one plant that will survive from neglect. There are approximately 300 species of Jade. C. Argentea is probably the best known one. It might be one of the most common house plants since it is a true survivor, practically forever-well almost; handed down from generation to generation. It has been in cultivation for over 100 years. We once had a friend who nurtured an especially large Jade plant who told his wife-to-be that one condition of marriage was her acceptance of his plant in their new home.

Jade have thick fleshy stems bearing thick green one to two inches long leaves with a reddish tinge on the edges. It can reach two feet in height although my friend's Jade plant was considerably taller. They are slow growers. New young plants make great dish garden plants. It is very adaptable to temperature variations; one reason it grows so well indoors. They prefer night time temperatures in the 50's and days in the 70's, but will grow anywhere between 45 to 100 degrees. Do not let temperatures drop below 45F. There is a miniature variety with only one-half inch leaves for smaller indoor areas or dish gardens.

Although Jade needs full sun and low humidity to perform best, it will survive in bright, indirect sunlight, but the stems may be weakened by more pendulous leaves lacking the traditional reddish edge tinge seen on plants grown in full sun. If moving it from subdued light to a bright sunny location, move it to bright sunlight in stages as it will sunburn until acclimated.

Older or pot bound Jade plants may begin bearing small fragrant white flowers during winter. But, conditions have to be correct for it to do so. Blooming is triggered by shortening of days and may occur around Christmas in our area. It needs periods of darkness to bloom so do not leave it in an area where night time lights will hinder the dark period. See last week's column on Christmas Cactus. Jade has a need for a slight period of dormancy in winter, so reduce watering to once a month and no fertilizing during winter months from November through March.

Water liberally approximately once a week, depending on a finger soil test (checking for moisture one-half inch below the surface) but allow soil to become nearly dry between thorough waterings. Over-watering may encourage rot so water only when soil is nearly dry to touch. Remove any excess water after watering by preventing the pot from sitting in water. Most good, complete, liquid plant fertilizers containing trace elements will work for Jade plants. Fertilize following the label directions from April through October. One source recommends feeding every three or four months. Since Jade is such a slow grower, it might be a good idea to feed more sparingly than every other week. An alternative is to dilute the fertilizer solution down to one-half to one-quarter strength and run a series of tests, watching plant performance. If the plant is not grown in direct sunlight, its water requirements will be reduced.

With any plant that remains in a pot for long periods of time as in Jade, flush periodically with water to remove any build up of residual fertilizer before toxic levels are reached. Simply add water and let it run out of the bottom of the pot for a short period. Let it drain thoroughly and become fairly dry before watering again.

Jade can remain pot-bound for years. If repotting is desirable, it can be done anytime of the year. However, spring may be the best period as the plant is resuming growth after its winter dormancy. A typical potting mix consists of four parts sterile commercial potting mix to one part builder's sand. After repotting, do not over-water. The plant must be forced to send roots clear down to the bottom of the pot. Over-watering results in stunted, short roots not having to work to find moisture. So, once the plant is potted and the initial watering completed, let the soil mix remain on the dry side. Transplanting a very large plant may take a full year before the root ball is completely reestablished and the plant may need some sort of support for this long period.

Propagation is by cuttings; either stem or leaf, at any time of the year. Jade can be pruned and cuttings can be rooted. It may take two to three months for miniature Jade plants to develop. Stem cuttings seem to root faster than leaf cuttings. Dust cut area with a rooting hormone powder and let a callus form before planting. It may take one to two weeks for the callus to form over stem cuttings. Leaves will form the callus in only a few days. However, the plants resulting from leaf cuttings may be smaller. Rooting soil mix should be just barely damp and moisture very gradually increased as rootlets form. Ideally, soil temperatures of 75 to 80 degrees F will speed the rooting process. Allow at least four to six weeks for roots to form before transplanting. Once a new plant is established, use a ½ diluted strength liquid fertilizer.

Watch for mealy bug infestations. These bugs lodge in crevices where leaves meet stems and must be controlled or they will soon become an infestation. Mealy bugs are sucking insects looking like bits of cotton and do not like bright light so look for them in sheltered areas as on underside of leaves. Heavily infested plants may drop flower buds. Treat with a cotton swab saturated with 70% isopropyl rubbing alcohol. Rinse the plant, if possible, with the spray attachment from the kitchen sink after treatment.

Jade can be placed outdoors after evening temperatures rise above 45 degrees as in late May or early June. It thrives in bright sun but from time to time it will need attention to its water requirements. The plant should be moved gradually into direct sun to allow it to acclimate to the sun's intensity and prevent the plant from becoming sun burned. Remember to bring it back indoors well before killing frost in Fall.

Jade makes a wonderful addition to the houseplant collection. It is a great plant for beginning indoor gardeners, although its flowering habits may be disappointing. It requires a lot less attention than most other houseplants and will remain green all winter long. If you haven't grown a Jade plant, why not give it try?

Most past Master Gardener articles can be accessed from our web page at http://www.cce.cornell.edu/yates/MGIndex.htm or by calling the Cooperative Extension office. For all your lawn and garden questions, call the Master Gardeners at
315-536-5123 leaving your name, question, phone number, and a time we may return your call with the results of our research. If you are interested in becoming a Master Gardener, a new class will be forming in January. Call the Co-op Ext office for details.