GROWING JAPANESE MAPLE TREES
YOUR GUIDE TO JAPANESE MAPLE TREES
Japanese maples originated in Japan and have been cultivated for over 300 years. Over this time, they have been bred for wide diversity in forms, sizes, shapes, and colors. There are more than 1,000 varieties, making them one of the most versatile landscape trees available. There's a Japanese maple for just about any landscape. Selecting, planting and caring for them is easy. Let our team of experts help you find the perfect Japanese maple at our Bellevue nursery.
JAPANESE MAPLE TREES SHAPES
JAPANESE MAPLE LEAF FORMS
Japanese maple trees with variegated and multi-colored leaves need more shade than those with red or green leaves.
Trees with dissected leaves can't tolerate as much direct sun or wind as palmate-leaved trees and will need some shelter.
SELECTING YOUR JAPANESE MAPLE TREE
Success with Japanese maples starts with planting it in the right location, which means light, space, and soil need to be considered before planting. We're assuming that the location is in USDA zones 5-8, which covers a great swath of the Pacific Northwest. The next step is to start by answering a few questions.
How will you use your Japanese maple tree? This will guide you in selecting the size and shape.
What leaf colors and leaf types appeal to you? This will help dial in which varieties of Japanese maple to consider.
Is there enough space for the tree to grow? Keep in mind that the sizes shown on plant tags refer to the size of the tree in 10 years.
Is the location adequately sheltered from winds? Strong winds can result in leaf burn due to rapid water evaporation. Root burn can also occur because strong winds can expose their shallow root systems and leave them exposed.
Does the sun exposure in the location meet the light requirements of the variety you want to plant? Observe how the light shifts throughout the day of your desired planting location. With too much direct afternoon light, leaf scorch can be an issue. Be sure to read the plant tag to know how much sun exposure is needed.
Does the soil have enough drainage? Japanese maples do not like to sit in standing water, so swamp-like conditions are a big “no”. If the location has clay or tightly compacted soil, you will want to amend it with material that loosens the soil structure, such as a soil conditioner.
Before you plant, prepare the soil. Japanese maple trees like slightly acidic to neutral soil with some organic matter that drains well.
Clay soils should be amended to provide more drainage. Japanese maples don't like wet feet, and poorly draining soil will cause root rot.
HOW TO PLANT YOUR JAPANESE MAPLE TREE
1
Dig a hole three times the diameter of the root system, with a depth no deeper than the original soil line on the trunk.
Prepare the soil. To encourage the root system to establish quickly, mix the the soil with compost or rhododendron/azalea planting mix (about 20% ratio of amendment to existing soil). Always use fresh material when amending your soil. Don't use soil from other areas in your garden.
If you're working with clay or deeply compacted soil, amend it with coarse organic matter like compost or a soil conditioner.
Quick Tip: Sawdust, wood chippings, or uncomposted bark should never be used. These materials will use up nitrogen that would otherwise be available to your Japanese maple for healthy growth.
2
Place your Japanese maple in the planting hole and position it so that the original soil line is level with the ground surface when planting is complete. Begin to fill the hole with the amended soil.
Before you finish filling the hole with the remainder of the soil, water the hole to help settle the soil that's around the roots. Fill the hole with water and allow it to drain completely. Once the water has drained, fill the hole with the remainder of soil. Add more soil as needed to ensure that soil line on the trunk is level with the ground surface.
Mulch with a 4"-5" layer of compost or mulch. Spread it away from the trunk. Piling mulch up against the trunk will cause it to rot.
Quick Tip: A layer of mulch over the shallow roots helps them to retain moisture and stay cool in summer heat. Mulching also protects the root system from being damaged by sun and wind.
3
Water your tree once more, so that the additional soil will settle.
Consistent and adequate watering is essential to the health of Japanese maples. It's important to not go from parched soil to flooding it with water, or vice versa.
CARING FOR YOUR JAPANESE MAPLE TREE
1
Moisture. Japanese maples don't have any unusual water requirements. While they don't do will in swampy conditions, they do need regular watering to maintain an even amount of moisture. How often you water and how much water you provide will be based on your specific growing conditions. However, as a general rule, water when the first two inches of soil is dry. The key to success is to keep the watering consistent. Pay particular attention to your Japanese maple's water needs in the first year. Over time, it will require less water.
Quick Tip: You can check your soil's moisture level by inserting your finger 1-2 inches in the soil. If it's dry, it's time to water.
2
Light. In the Pacific Northwest, all day sun is usually not a problem for either type of tree. Sun exposure does become an issue in the summer, though, when direct afternoon sun and intense heat can cause leaf burn. Even palmate leaved Japanese maple can experience leaf burn if left exposed in hot afternoon sun. For this reason, it's particularly important to ensure your tree is adequately hydrated and shielded from intense heat and direct afternoon sun. Generally, Japanese maples with dissected leaves grow best in morning light with light or dappled afternoon shade. Japanese maples that have palmate leaves can tolerate more sun. Japanese maples with variegated leaves need more light than shade to produce variegation. All Japanese maples will need some amount of sunlight to produce vibrant autumn color.
3
Fertilizer. Japanese maples are not heavy feeders. They can be fertilized once or twice a year with a slow release fertilizer that's formulated for Japanese maples. Early spring (right after the last hard frost) is a great to time to fertilize and should be done before the leaf buds begin to emerge. Aim for low levels of consistent nutrition throughout the growing season. At our Bellevue nursery, we like to use Happy Frog Japanese maple fertilizer, as it provides consistent, low levels of nutrition and contains mycorrhizal fungi, which helps nutrient uptake and water absorption by the roots.
Quick Tip: Wait to fertilize your Japanese maple for at least a year after planting. This will allow your tree to become established, with the root system better able to uptake the fertilizer.