Emperor Japanese maple trees dazzle all year round. In spring and summer, their stunning foliage takes on a rich burgundy hue before turning scarlet in fall and dropping in winter to reveal black-red bark. Emperor Japanese maple trees’ leaves have skin with a translucent sheen, making them shine from within when the sun hits just right. These beauties make compact specimen plants perfect for smaller yards. Their exceptional cold-hardiness allows them to be grown in cooler climates. Here’s everything you need to know about Emperor Japanese maple trees.
Emperor Japanese Maple Trees at a Glance
- Showy, brilliant red foliage for three seasons
- Compact
- Disease-resistant
- Low-maintenance
- Cold-hardy
- Fast-growing
Pro Tip
- When selecting any Japanese maple, TOH landscape expert Jenn Nawada advises choosing “a Japanese maple that fits your space.” A single strategic pruning cut at an angle on a crossing branch can dramatically improve a tree’s overall shape and long-term structure.
Emperor Japanese Maple Tree Appearance
Emperor Japanese maple trees grow in an upright form with a wide crown that doesn’t require pruning. Their leaves resemble pointed, small-scale versions of traditional maple trees and are outstretched like hands.
Emperor Japanese maples are compact trees, growing to 12–15 feet tall with a 12–15 foot spread. Their small stature makes them a natural fit for smaller landscapes. Faster-growing than other maple varieties, Emperor Japanese maple trees grow more than 2 feet per year before reaching their full height.
Specifications
Hardiness Zones
USDA Hardiness Zones indicate the regions where plants can grow based on minimum winter temperatures. Emperor Japanese maple trees grow in Zones 5–8, which cover most of the country, aside from the coldest regions.
- Keep in mind that hardiness zones have shifted over time. As Jenn Nawada explained on Ask This Old House, areas like Boston have moved from Zone 5 to Zone 6, and even Zone 7 near the coast. This means you may want to consider microclimates in your own yard—a south-facing, wind-protected spot can create conditions that effectively bump you up a zone, giving your Emperor Japanese maple extra protection in borderline areas.
How to Plant Emperor Japanese Maple Trees
The best time to plant your Emperor Japanese maple tree is in spring or fall. We recommend taking these steps:
- Choose a planting site that receives partial shade to full sun. Their leaves are more bold when grown in partial shade.
- Clear away any weeds, turfgrass, or debris.
- Dig a hole the same depth as the container that your tree came in and three times the width.
- Carefully place your tree in the hole.
- Begin backfilling the soil. When you reach halfway, water the hole well. Once the water has drained away, continue filling the hole. When the hole is filled, place a 2–3 inch layer of rich, organic mulch on top of the root zone, being mindful not to let it touch the trunk.
- Repeat the mulching process each spring to help conserve moisture and insulate your tree from extreme temperatures.
- Finding the Right Depth: When digging your hole, make sure to expose the root flare — the point where the trunk’s base flares out and the first roots emerge. As TOH landscape contractor Roger Cook has shown on project sites, you want that root flare planted right at grade, not buried beneath the soil. A helpful trick: pull a string line across the top of the hole and measure down to confirm your depth matches the root ball height exactly.
Growing Conditions
Emperor Japanese maple trees are exceptionally low-maintenance, adaptable to a wide range of soils, and not very picky about the amount of light they receive. Their leaves bud later in spring than other Japanese maple varieties, allowing them to withstand damage from late frosts.
- Sun and Shade: Emperor Japanese maple trees thrive in partial shade, which leads to the boldest coloring. However, they can also grow in full sun—just make sure they receive at least some dappled shade in warmer climates.
- Soil: Emperor Japanese maple trees are highly adaptable to a wide range of soils. However, they have a preference for well-drained, moist soil with a neutral to slightly acidic pH level.
- Watering: For the first few seasons, you’ll need to water your Emperor Japanese maple well, about once to twice a week. After that, only water once a week or whenever the soil loses its moisture. You can check this by inserting your index finger into the top 2 inches of the surrounding soil and testing to feel if it’s dry.
- Fertilizing: Feed your Emperor Japanese maple with a slow-release, balanced fertilizer in spring, before new growth emerges.
- Pruning: Emperor Japanese maple trees do not require pruning to maintain their rounded shape. If you notice any dead, damaged, or diseased limbs, prune them in winter when the tree is dormant—you never want to prune your Emperor Japanese maple tree when the sap is running.
FAQ About Emperor Japanese Maple Trees
How fast do they grow?
Emperor Japanese maple trees grow faster than other types of Japanese maples, increasing by more than 2 feet per year.
How big do they get?
Emperor Japanese maple trees grow to 12–15 feet tall and wide.
Do they need to be pruned?
No, Emperor Japanese maple trees retain their rounded shape even without pruning. However, if you see dead, damaged, or diseased branches, you should prune them in winter.
Do their leaves turn green?
No, Emperor Japanese maple leaves are a deep burgundy shade in spring and winter, and turn fiery scarlet in fall before dropping.