Dieffenbachia

Spider Mites:

Spider Mites look like tiny dots on the underside of your plant leaf. They usually live in large groups, so you will definitely see more than one of these tiny dots in a group on the plant. Spider Mites are known as such from the silk webbing that they leave behind on infested leaves. This presence of webbing is the best indication that your plant may be infested. Another good indication that your plant might be infested with this pest or another is by studying your plants leaf. If you begin to notice the leaves are covered a lot of yellow pin pricks that may be a good indication.

Spider mites usually become a problem on outdoor plants after certain insecticides have been sprayed that may have killed the natural enemies of the mite. The best thing to do when dealing with Spider Mites is to find an insecticidal soap that you can use to wipe down the leaves. It is advised that you test out the insecticidal soap on a small portion of the plant before applying it to the whole plant. For indoor plants the best course of action is to remove or isolate the plant from the home to minimize possible spreading to other nearby plants. If only a small portion of the plant is infested, clip that section and dispose of the clippings. If the entire plant is infested and the plant holds no sentimental value best thing to do is dispose of the plant. If you want to try and save the plant do not waste your time with pesticides as they usually won’t have any effect on this pest. Treat the plant with an insecticidal soap every couple of weeks to help kill or keep the mites in control.

Aphids:

Aphids are commonly known as the greenfly or black fly, and they are the most common pest for indoor houseplants. They are small insects (usually 1 to 5mm) and generally infest flowers, shoot tips and soft leaves. They are not likely to kill your plant but these sap-sucking insects will cause the flowers and leaves to look very distorted and/or curled.

To treat the Aphid infestation you should first try to wash off the colonies from your plant. To do this use a strong spray bottle filled with water, however this treatment does not work with all species of Aphids. The next method to try is with a fine spray of soapy water on the colonies. This will interfere with their ability to breathe. If the second method fails, you will need to succumb and purchase a systemic poison or a spray containing Malathion. We suggest Malathion because it has a relatively low human toxicity.

Mealy Bugs:

Mealy bugs are white, waxy creatures that live in large colonies usually on the undersides of the leaves and/or around leaf joints. The bug is about 1/10th of an inch and has the look of cotton. Similar to other pests a sure sign that your plant is infested is if you observe that the leaves of your plant seem dry or weak (dropping). If you notice those signs the first course of action would be to isolate the infested plant from all other plants within your home. After that use a strong spray bottle with water in order to try to wash off the colonies from your plant, or wipe off the infestation with cotton buds dipped in rubbing alcohol. Take note that this may not work to get rid of all the Mealy Bugs at one time, so keep the plant away from others while you monitor it for more insects. Another option is to buy the Mealy Bug’s natural predator called the Mealybug destroyer (Cryptolaemus montrouzieri) which is a species of lady bug. This is an option for heavily infested plants, but is probably not practical unless you have a large number of infested plants. Once the Mealybugs have been killed and consumed the Mealybug destroyer will die off from a lack of a food source.

Scales:

There are many species of scales that are commonly found in indoor house or greenhouse plants. Some species of the insect can have an armored shell like covering that will protect its entire form while others will have none at all. Those with the waxy shell can have its protection removed by simply scraping it away. It is easiest to tell the difference as the soft scales (no armored protection) produce honeydew while the armored scales will not. Scales feed on your plant by sucking on the plant’s sap. This will promote poor growth which will eventually stunt the growth of your plant. It can also lead to your plant being infested to sooty mold.

The most practical thing to do for your first attempt at cleaning up your plant from its infestation is to use soap and water to wash off the leaves and stems. If your plant is heavily infested, you can try an insecticide spray schedule on your plant that involves 2 to 3 sprays a week every two weeks. It is usually best to discard the plant however before the infestation can spread.

Thrips:

There are many sub species of Thrips that can infest common indoor house hold plants. The insect is barely visible to the naked eye. In its adult form the pest is a brownish, black color with light markings on its body. The larvae can be a light yellow to orange color with black excrement on their backs. When a plant that this pest inhabits is disturbed the adult forms it can be seen to fly or run. This insect will feed on the juices of the plants leaves and/flowers. The damage that is left behind is random streaked silvered areas of the plant that are speckled with little black dots of excrement. The plants leaves and/or flowers may be blotched or drop away from the plant.

Labeled insecticides that state they can handle thrips are the best option for removal. Try a daily spray of 4 times a day for 4 days on both the plant and the soil to get rid of this pest.

Iron Deficiency:

It is not uncommon for indoor plants to experience the affects from Iron Deficiency. You can tell that your dieffenbachia may be affected by this deficiency by taking notice to the young leaves on the plant. There will be a slight yellowing, and/or shedding of new leaves that can also lead to the plant suffering from a stunted growth. This usually occurs to plants that are in poorly aerated soil or when the soil is over watered and saturated. Iron deficiency can be alleviated with regular applications of iron sulfate foliar fertilizer or for a long term solution the best way to alleviate would be to correct the poorly aerated soil and the water log problem.

Magnesium Deficiency:

The common house hold dieffenbachia can suffer from magnesium deficiency. It is easy to detect by simply observing the leaves of the plant as with most other deficiencies. If you notice interveinal yellowing or chlorosis around the margin of old leaves that would be one of the first indications. This is further identified with withering or curling of the leaves which will eventually lead to the burnt look around the tips of the leaf. The best/organic way to treat this deficiency is to take Epsom salt and mix it in with about 2 gallons of water. After doing so take a spray bottle and gently mist the plant a couple of times a week.

Nitrogen Deficiency:

If you start seeing some discoloration and yellowing of the leaves on your plant it is usually caused from a Nitrogen deficiency. The yellowing usually starts at the tips of the leaf and works its way inwards with no particular pattern. It will consume the oldest, lower leaves first until only the newest growth stays green. Here are a few recommended tips to handle a nitrogen deficiency. If you own a fish aquarium empty some of the aquarium water you have replaced into the soil of the plant. Another solution would be to spray the leaves of the plants with a foliar fertilizer [fertilizers made especially for applying nutrients to the leaves] with a mix of about 5-10-5 (percentage of nitrogen, phosphorus, and potassium).

Potassium Deficiency:

Symptoms of Potassium deficiency vary among plant species, but always appear first on the oldest leaves. Older leaflets of some palms are mottled with yellowish spots that are translucent when viewed from below, followed by the leaves rolling and giving a burnt look (necrosis) from the tip inward. In other plant varieties symptoms of Potassium deficiency are older leaves that appear withered and frizzled with yellow tips and brown margins. Yet in other cases symptoms appear on older leaves as marginal or tip necrosis with little or no yellowish spotting present. When left unaddressed it will progress from the older leaves to the younger leaves, eventually killing the plant. Potassium is responsible for chlorophyll formation which plays an important part in the strength of cells, in turn enhancing the ability of the plant to resist plant diseases, insect attacks and cold conditions. The best way to take care of Potassium deficiency is to use a fertilizer that contains Potassium Sulfate. A note of caution though; an excess of Potassium may tend to delay maturity.