• There are more than 240 cultivars of Japanese maple.japanese maple image by Horticulture from Fotolia.com
  
  Japanese maples, which are native to Japan and Korea, but are found in gardens all over the world, are prized for their spring and fall foliage color and unusual leaf shapes. Slow growers reach up to 25 feet tall, and weeping varieties grow as wide as 15 feet. Most of the causes of brown tips on Japanese maples are easy to mitigate and don't pose a huge threat to the health of the tree, though they may create aesthetic issues as the leaves die off.
  
  

Underwatering

• If the tree isn't getting enough water, the leaves will start to brown and curl. Make sure potted Japanese maples have good drainage. Water them when the top inch of the soil dries out. Test this by sticking a finger into the dirt up to your first knuckle. If your finger remains dry, water the plant until the water comes out the drainage holes in the bottom of the pot. Trees that are planted in the earth should be watered thoroughly at least once a week and more often during drought conditions. Place soaker hoses around the base of the tree and leave the water running for an hour. Three to 4 inches of mulch will help keep the tree hydrated.
  
  

Overwatering

• Overwatering can also cause brown tips on Japanese maples. Standing water around the base of the tree will eventually drown it, and excessive water on the bark of the tree creates conditions that promote disease. Make sure that potted trees have good drainage by placing a layer of small rocks in the bottom of the pot before you plant the tree. Check the drainage holes, which should not be clogged.
  
  

Leaf Burn/Leaf Scorch

• Japanese maples are susceptible to leaf burn if they're exposed to too much sunlight during the afternoon, especially when temperatures are high. The leaves dry out more quickly than the roots can supply water. Over the course of time, the entire leaf turns brown and falls off. When you plant the tree, be sure to plant it where it will get morning sun and afternoon shade. Potted trees can simply be moved to a shadier location. Misting potted plants will add humidity and reduce the risk of leaf burn. Bacterial leaf scorch is a disease that affects landscape trees, such as the Japanese maple, and has no known cure. According to the University of Maryland Extension Service, scientists are experimenting with pruning and antibiotic therapies.
  
  

Disease and Insects

• Avoid fungal diseases with proper watering. Wait until the top three or four inches of the soil around a planted tree is dry before watering. Don't let sprinklers dampen the trunk of the three and make sure the water soaks into the ground. If you suspect your maple tree has a fungal infection, prune back dead branches and use a high-nitrogen fertilizer once a month. Caterpillar or aphid infestations are not usually severe enough to cause damage to the leaves. Check the undersides of the leaves and use a pesticide designed for the particular insect you discover only if the problem is serious.