Blood-red stems on a maple do not indicate disease or any other problems with your tree. Instead, it is likely that you have a particular cultivar of the Japanese maple (Acer palmatum). The cultivar is called "Sangokaku" and it is prized by home gardeners for its bright-red branches.
1. Red Bark & Appearance
Acer palmatum "Sangokaku" is a small maple with delicate leaves and distinctive, blood-red branches. The younger the branches, the brighter the color, so often it is the stems and twigs that are the most vibrant. Also called the coral bark maple, the color of the bark deepens in the winter and is especially attractive against snow. Spring flowers are purple, and the summer foliage is light green with red margins. The leaves are deeply lobed, giving them a delicate, feathery appearance. In the fall, the foliage deepens to gold before it drops off the tree.
2. Size & Growth Habit
The coral bark maple reaches a maximum height of about 205 feet tall, with an maximum average canopy width of about 20 feet. Each leaf lobe averages about 2 inches in length. The tree grows at a moderate pace and can present as a multi-stemmed shrub or as a single-leader tree. The tree is hardy and can become invasive in some areas, according to Missouri Botanical Garden.
3. Climate & Culture
Acer palmatum "Sangokaku" is hardy in U.S. Department of Agriculture plant hardiness zones 5 through 8, according to Missouri Botanical Garden. It tolerates cold temperatures very well, although late frosts may damage newly emerging leaves. The tree grows equally well in full sunlight or partial shade as long as it is located in rich, well-draining soil. It will not grow well in hot, dry areas or in areas exposed to strong winds.
4. Growing Conditions
To better enjoy the striking, blood-red stems of this tree, locate it where you can easily see it, especially in the winter. The Missouri Botanical Garden suggests pruning off older branches to allow new ones to grow, as the new growth will be much more vibrantly colored. The hue fades as the wood ages, and it also tends to fade in the heat of the summer.