Pachira aquatica is commonly known as Malabar chestnut or Guiana chestnut in its native tropical regions, but is also sold in North America as a smaller variety called money tree. Winter hardy in U.S. Department of Agriculture planting zones 10 through 12, money tree is used as a tropical ornamental or as the centerpiece of a rain garden, but can also be grown indoors as a houseplant. Money tree is relatively free of problems, but may develop yellow or brown spots on leaves under certain conditions.
Money tree can reach a height and spread of 20 to 30 feet in the home landscape when grown outdoors. The compound leaves are an evergreen lance shape, while the fragrant flowers, which are yellowish-white with red-tipped stamens that resemble a shaving brush, bloom in late winter to early spring. Flowers are followed by woody pods shaped like footballs that burst when mature to reveal edible nuts inside that taste like chestnuts.
Water and Light
Money tree is a tropical plant, requiring full sun or partial shade, a fertile and humus- rich soil, and either a wet environment or plenty of watering. It also doesn't tolerate strong winds. If any of these conditions aren't met, money tree leaves can develop yellow or brown spots, droop and fall off. To prevent and remedy the problem, water the tree generously and often, and apply a balanced 10-10-10 liquid fertilizer to the soil around the tree once a month during the growing season.
The Phytophthora palmivora fungus can attack money tree plants, causing dark brown to black water-soaked spots on leaves that turn papery as the disease progresses. Cultural control includes removing infected leaves and debris around the tree, harvesting the nut pods frequently, and thinning the canopy to improve airflow. No recommended fungicides exist for this particular pathogen.
Mealy bugs are tiny insects that look like small pieces of cotton and suck the sap out of money tree leaves, causing spots that are yellowish-brown, leaf drop, weak stems and slow growth. One tell-tale sign of the bugs is the sticky honeydew substance they leave behind. Scale is a similar type of pest, appearing as small bumpy brown spots that appear to move. When mealy bugs are young and crawling, use sticky traps to catch them. On older insects, spray leaves with a solution of equal parts water, alcohol, liquid soap and mineral oil, and repeat every 10 days for a month. With scale, wipe affected leaves off with a cloth and spray with neem oil.
Money tree grown indoors as a small tree or bonsai typically only grows 6 to 8 feet, often with a braided trunk. Money tree houseplants perform best with a couple of hours each day of east sun, or filtered sunlight in a south or west window to prevent brown or spotted leaves. Keep temperatures between 50 and 90 degrees Fahrenheit, and away from cold drafts and heat from air conditioning vents. Provide a moderate but even moisture content to the soil; and if the interior has low humidity, place the plant on a wet pebble tray. If plants become infested with the pathogens or insects referenced above, the same treatment procedures apply.