What Is the Black Dirt on My Outside Furniture?

Mold

• Mold spores spread quickly, infiltrating furniture that is porous. Memnoniella mold is a fungus type of mold that grows on wood. Cladosporium mold grows on all types of outdoor furniture. Alternaria and mucor mold is found in soil underneath outdoor furniture. These common outdoor furniture molds can cause severe allergic reactions, including respiratory distress such as coughing, wheezing, runny nose and bronchial spasms. If mold comes into contact with skin, people may develop rashes and itchiness that ranges from mild to severe. Sensitive people or those with weakened immune systems may also become disoriented from dangerous mold spore inhalation.

Identification

• Mold is dark gray, green or light black in color. It may appear splotchy, with whitish gray sections and a fuzzy appearance. Mold will not be easily cleaned by hand. Mold will not be raised but rather ingrained on a surface such as outdoor wood.

Mildew

• Mildew is a byproduct of mold and can be troublesome for certain individuals sensitive to mold as well. Mildew makes furniture look ugly and stained. Common types of mildew on outdoor furniture are botrytis, wallemia and basidiospores.

Identification

• Mildew is black, grayish, or light grayish in color. Mildew flourishes in damp, warm places. Mildew is commonly found on outdoor furniture in the south, where the environment is naturally humid. Often to the sensitive individual, mildew will have an odor. If mildew growth is widespread on furniture or furniture cushions, it will have an obvious musty odor. Mildew contributes to allergic reactions in people ranging from itchy rashes, runny nose, vomiting, and respiratory problems including asthma and lung infections.

Prevention/Solution

• Mold on plastic furniture such as resin, is easily removed with orange oil and a clean rag. For mold on wood outdoor furniture, use a mixture of chlorine bleach, water and a scrubbing brush to remove. Furniture can be treated with mold resistant varnish or paint to eliminate and prevent recurrence of mold growth.To remove mildew, use a furniture cleaner made for wood, upholstery or resin furniture. If mildew is more stubborn, chlorine bleach and water can be used to remove stains. Regular cleaning and keeping furniture dry can help eliminate mildew growth.

Grime

• Dark and thick stubborn dirt that is not easy to remove but does lift from the surface with some effort is grime. Grime is accumulated dirt that is dried and set onto furniture. It resembles the consistency of old grease, yet comes off with cleaning products meant to remove grime, or by scrubbing with a hard bristled scrub brush. Covering outdoor furniture with furniture covers protects from grime buildup.

Soil

• Brown to black loose dirt on outdoor furniture is soil, mostly found on outdoor furniture chair or table legs. Soil is easy to clean off furniture by using a simple cotton cloth and mild detergent. A garden hose may be all that is needed to remove loose soil. Keep outdoor furniture away from dirt areas on the lawn to eliminate soil from accumulating.