Dust and grime can take a toll on the good looks of your houseplants, giving their once-glossy leaves a dullness that is not only unattractive, but which inhibits proper food and light absorption. Give your plants a good dousing with water to remove dust and debris, then use leaf shine to restore the leaves' lustre. Purchase a commercially made leaf shine product or use everyday items from your kitchen.
Although it seems like an unlikely product to put on your plants' leaves, mayonnaise is said to shine them up nicely. Ray Barkalow, an orchid specialist with more than 35 years of experience and the proprietor of the First Rays website, recommends mixing mayonnaise with water to form a thin paste, then dabbing a bit of the mixture on a soft cloth. Wipe the cloth gently over each individual leaf, being careful to remove as much of the paste as possible.
Olive oil is recommended for shiny leaves by the folks at the Nursery Retailer website. They recommend placing a tiny bit of oil on a barely damp cloth, then individually wiping leaves to apply an extremely thin coating of oil. To keep the oil from building up to dangerous levels, they recommend giving the plant a gentle, warm shower every few weeks along with a thin coating of oil every three or four months.
Diluted milk is another homemade shine concoction recommended by Barkalow. He advises plant owners to mix equal parts of whole milk and water, then wiping it on leaves with a soft cloth and allowing it to dry to a shine.
Experts don't agree whether it's safe to use leaf shine products. Some recommend them while others say that they can clog or block a plant's stomata, which are tiny openings in a leaf's surface that allow water, oxygen and carbon dioxide to enter and exit the leaf. Those who feel that leaf shine is harmful recommend giving plants a thorough but gentle washing in the shower or with a hose-end sprayer, and using a gentle liquid soap if the plant is dusty or dirty. If you do use leaf shine, do so only occasionally -- perhaps once every several months. Giving showers to and using leaf shine on cacti, succulents or fuzzy-leafed plants is not recommended.