Brown Dieffenbachia Leaves

My Dieffenbachia is turning brown and losing leaves. What am I doing wrong?

Dieffenbachia

If we have some knowledge of where a house plant originates, we can then try and duplicate those conditions in our home, thus providing an environment favourable to the plants health. 'Dieffenbachia' or Dumbcane, as it is commonly called, is native to tropical America (Costa Rica and Colombia, for example) as well as the West Indies. Dieffenbachia is named in honour of Herr J. F. Dieffenbach, a German botanist who supervised the imperial gardens at Schonbrunn Castle in Vienna in the 19th century. The common names of the plant, 'Dumbcane' and sometimes 'Mother-in-laws-Tongue', are derived from the effects the toxic or poisonous sap of the plant has on a person's mouth and throat if it should be eaten or chewed. The sap contains calcium oxolate crystals which causes swelling and pain of the mouth and throat, as well as speechlessness in many cases. It is for this reason, very important to keep the plant out of reach of children and pets, and to wash the hands after handling the plant. Dieffenbachia belongs to the Arum family, 'Araceae'.

Dieffenbachia plants are easily recognized by their large, brittle, oblong or ovate, often drooping, variegated leaves. The green leaves are either spotted, blotched, or streaked with cream, white, yellow, gold, silver, or a combination of these colors. Depending on the species or cultivar, the leaf size ranges from 8 inches long to over 2 feet long. If the leaves should be bruised or cracked, which they do very easily, they often give off a skunk-like odor. Be careful when handling or moving the plants so as not to damage the leaves. The leafstalks sheath at the base of the plant and encircle the normally non- branching stems (like a tree, not a shrub). Although some plants can reach a height of 6 feet or higher, they usually end up looking like a palm tree by this time due to the fact the bottom leaves drop off the plant as they mature. This is a good time to rejuvenate the plant, and perhaps start a few more plants using various methods of propagation to do so. The top part of the plant can be air-layered, and once it has rooted and been removed from the plant, the stem can be cut back to 4 - 6 inches from the pots rim to stimulate new growth from the short stub. The remainder of the stem can then be used to make cane cuttings. To make cane cuttings, cut the bare stem into 4 - 6 inch long pieces, being sure each piece has at least one node (a small green swelling on the cane). Lay the pieces of cane horizontally in moist sand or any rooting medium with the majority of the nodes facing upwards, and bury only the lower half of the cane in the media. Once the new shoots reach approximately 2 inches high, cut them from the cane with a small piece of the cane attached, and root these shoots in moist sand. Once rooted, they can be potted up in 3 or 4 inch pots in proper compost or soil. Alternatively, insert the pieces of cane upright (vertically) in the moist sand. Bury the bottom 1/3 of the cane, being sure to bury the end which was the lower part of the stem. This is the method used to produce a 'Ti-plant'.

Dieffenbachia

Because these are tropical plants, they require a warm, humid environment to succeed. Daytime temperatures of 75 - 85 degrees F, and nightime temperatures of 65 degrees F (no lower) are ideal. If temperatures are too cold or the plant is subjected to cold drafts, the leaves will either develop brown edges, turn completely brown and drop, or the lower leaves will turn yellow and wilt. Extreme or fluctuating temperatures can kill some delicate varieties. Along with warm temperatures, a high level of humidity should be maintained. If the air is too dry, the young leaves will often fall. Place damp peat moss around the pot, use pebble trays, or set basins of water near heat registers to increase humidity levels around the plant. Mist the leaves in the morning hours of each day if humidity levels are very low. Wash the leaves at least once a month with warm, soapy water to clean them and also remove any insects which may be harbouring on the plant. Rinse with clean water. Never use leaf shine products on the leafs.

Dieffenbachia camille

Provide 400 foot candles of light for Dieffenbachia plants. This is a bright, indirect light, such as a curtain-filtered south window. Direct sun shine can bleach or fade the leaf coloring, whereas, too dim a light will either cause the plant to lose its variegated colors and revert back to green, or, the lower leaves could dry up and fall.

Dieffenbachia compacta

Watering can be a touchy subject with this plant. While the plant is actively growing, keep the soil moist to moderately dry. The media must never be soggy wet, as overwatering will cause the lower leaves to drop. In winter, or the dormant period, the plant will need to be watered more sparingly, especially if room temperatures are on the cool side. The plant is very susceptible to crown and stem rot disease when a combination of overwatering and low temperatures co-exist. If the soil is allowed to dry out, the leaves will develop brown edges.

Dieffenbachia tiki

Dieffenbachia generally require fertilizing only every 2 or 3 months while they are actively growing. Use a plant food such as 5-10-5 diluted to 1/2 the strength recommended on the fertilizer containers label. Never feed the plant while it is dormant.

The most common pests of Dieffenbachia include mealybugs, aphids, red spider mite and scale. A humid atmosphere helps in detering these insects. If an insecticide is needed for control of a heavy infestation, choose one that is recommended for use on Dieffenbachia as listed on the containers label. These insecticides can be found at most garden centers or hardware stores. Diseases common to the plant are leaf spot, stem, crown and root rot, anthracnose and Dasheen mosaic virus.

Dieffenbachia Tropic Breeze

The genus 'Dieffenbachia' contains over 12 species, as well as over 50 introduced cultivars. A few of the more common species include: D. amoena - dark green to blue- green leaves feathered with white; D. bausei - yellowish-green leaves with green margins and white spots (a hybrid plant); D. bowmannii - large green leaves with white spots; D. chelsonii - deep, satiny green leaves marked with gray feathering; D. exotica (arvida) - a good smaller plant for the home, dull green leaves variegated with creamy white; D. fournieri - almost black-green leaves with white spots; D. fosteri - green leaves, a short dwarf variety; D. hoffmannii - velvety green leaves blotched with cream or white and prominent white mid-ribs (the main vein of the leaf); D. imperialis - bright green leaves with soft yellow blotches; D. leonii - green margined velvety yellow leaves; D. longispatha - light midribs, dark green leaves; D. memoria-corsii - gray colored leaves with ivory spots and green veins; D. oerstedii - dark green leaves with prominent white mid-ribs; D. parlatorei - shiny, deep green leaves; D. picta - green leaves blotched with white; D. picta barraquiniana - green spotted white leaves with prominent white center veins; D. picta jenmannii - green leaves with white veins in a herringbone pattern; D. picta superba - green leaves spotted or blotched with cream, a very compact form; D. sequine liturata - velvety green leaves with white center veins; D. splendens (hybrid) - bronzy-green velvety leaves spotted with white and white mid-ribs.

Dieffenbachia Tropic Marianne

A few of the many cultivars include: 'Alix' - green and white variegated leaves; 'Camille' - creamy white leaves edged with green and green mid-rib; 'Rebecca' - compact, creamy white leaves splotched with green and yellow; 'Rudolf Roehrs' - white blotches on gold- green leaves with dark green leaf edges and dark green mid-rib; 'Compacta' - creamy white leaves with green spots; 'Tropic Star' - bright creamy-yellow with irregular green splotches; 'Silver' - silver and green leaves; 'Nelly' - green leaves with cream, slow growing and compact; 'Pittieri' - emerald green leaves with white and ivory patches; 'Wilson's Delight' - large, solid-green leaves with white mid-ribs; 'Perfection' - green and cream variegated leaves.