The Katsura is a deciduous tree with a moderate to fast growth rate. It is a medium-height tree growing about 50 feet tall, well suited for an average urban or suburban property. It also has dwarf-sized varieties that grow to about 15 feet in height. The Katsura, named after a town in Tokushima prefecture in Japan, grows in single-stem and multi-stem variations and has yellow leaves in fall. It has a rounded or pyramidal plant form and looks attractive with its heart-shaped leaves lining up opposite one another along the branches.
The Katsura is a dioecious plant, producing male and female trees separately. Its flowers are inconspicuous and unremarkable but indicate whether you have a male (red) or female (green) specimen. It grows best when planted in late winter or early spring. It is nicknamed the "caramel tree" for its sweet, caramelized sugar or cotton candy fragrance in the fall.
|Common Name||Katsura tree, Japanese Katsura|
|Botanical Name||Cercidiphyllum japonicum|
|Mature Size||40 to 60 ft. tall, 25 to 60 ft. wide|
|Sun Exposure||Full, partial|
|Soil pH||Neutral to slightly acidic|
|Flower Color||Red, green|
|Hardiness Zones||4 to 8|
Katsura Tree Care
Katsura trees prefer rich soil, so mix compost with the soil when planting these trees. Compost feeds plants and improves soil drainage. Katsura trees are easier to grow because it tolerates certain soils that can be tough for other trees.
This tree grows best in evenly moist soil, and mulch helps with moisture control. Apply a layer of three inches of mulch over the soil surface after planting to help the ground retain moisture. An added benefit of organic mulches, like bark mulch, is that they add nutrients to the soil and improve drainage as they break down.
Katsuras can be grown in partial shade because they are understory trees (a tree that grows under the canopies of larger, taller trees) in the wild. For trees that grow in the southern or hotter areas of their range, grow them a bit of shade to prevent their leaves from getting scorched in the summer. In the North, give them full sun, and they will achieve better fall foliage color.
This tree prefers enriched soil that is well-drained and relatively moist with a neutral to slightly acidic soil pH. However, the Katsura can also tolerate clay soil, acidic soil, and salty soil.
Katsuras have moderate watering needs overall, roughly 1 inch of water per week, but may need more frequent watering in dry areas. Water as required to keep the soil moist (but not wet) until the tree is well established. Once established, it also becomes somewhat drought-tolerant.
Temperature and Humidity
Suitable for zones 4 to 8, this tree can tolerate a relatively broad temperature range and is not too picky about humidity. In damp climates or rainy seasons, avoid watering from overhead to prevent leaf mildew.
In the beginning, as a young sapling, fertilize using a higher nitrogen mix fertilizer (20-20-20 NPK). As the tree grows and becomes established, use a balanced, general-purpose fertilizer (10-10-10) and soak the ground well afterward to ensure that the fertilizer goes down to the roots. You can use granular, liquid, or stake fertilizers; follow the package instructions. In general, fertilize once a year in late fall or early spring before buds develop.
Types of Katsura Trees
- 'Red Fox' Katsura tree (Cercidiphyllum japonicum 'Rotfuchs'): Smaller variety (30 feet tall, 16-foot spread); one of the most colorful types, bearing purplish-bronze leaves in spring, greenish-bronze leaves in summer, and orange-bronze in fall
- 'Ruby' Katsura (Cercidiphyllum japonicum 'Ruby'): Small (30 feet tall); sports blue-purple leaves
- 'Dawes Ascension' Katsura (Cercidiphyllum japonicum 'Dawes Ascension'): On the taller side for katsura (50 feet); has a columnar shape for the first decades of life; green-blue leaves turn apricot yellow in fall
- Dwarf varieties 'Heronswood Globe' Katsura, 'Glowball' Katsura, 'Boyd's Dwarf' Katsura, 'Herkenrode Dwarf' Katsura, and 'Kruckeberg Dwarf' Katsura: Smallest of the cultivars, topping out at 8 to 15 feet
- Weeping Katsura tree (Cercidiphyllum japonicum 'Pendulum'): 15 to 25 feet high, with a similar to slightly greater spread; branches of this smaller type droop down, looking visually interesting
Full-grown Katsuras typically do not need pruning other than seasonal cleanup and maintenance. Train the growth of the tree when it's young. The best time to prune is in the late fall after leaves have dropped or early spring before it produces sap. Remove crossing or crowded branches. Also, you can remove low branches, no more than one or two per year, to train the clearance under the tree. After the tree is established, it should only need pruning every three to five years. Check the tree each spring, and remove any suckers or dead branches.
Propagating Katsura Trees
Katsura trees are best propagated from seeds, but they can also be grown from stem cuttings or suckers during late spring. A stem cutting is propagated from a healthy stem of softwood or semi-hardened stem. Using sterilized scissors or pruners, get a cutting that is 6 to 8 inches long and has at least four to eight leaf nodes. Remove all the leaves except for the two topmost sets.
If the Katsura tree has suckers or offshoots growing from the base of the tree, you will have a greater rate of propagation success. Pull it off, but first, make a notch using a sharp, sterilized blade about 1 inch below the sucker. As you pull or peel off the sucker, you will get some bark with the basal cutting, without excessively damaging the tree and giving it a better chance of healing cleanly. If you neglect to notch the trunk, the bark may peel off a lot and injure the tree.
- Once you have your cutting or sucker, you'll need nursery pots mixed with garden and potting soil, rooting hormone (optional), and a clear plastic bag.
- If using rooting hormone, dip the cut end and exposed nodes into the rooting hormone.
- For each pot, use your finger to make a hole deep enough to bury at least two nodes of the stem cutting. Press soil lightly around the stem to ensure contact with the soil.
- Water the plant abundantly until the water drips out of the drainage holes and place the plant above a tray of pebbles.
- Wrap the pot and its cutting in a clear plastic bag to keep moisture in, which promotes rooting. It can take up to 6 weeks to develop roots. Keep the bag on plant until you notice growth. You can allow air in for one to two hours a day to promote some air circulation, but then replace the bag and make sure to maintain moist soil.
- Place the plant in indirect light never direct sun.
- Transplant into the ground after a year. The best time is in the fall when the plant is nearing dormancy; it reduces transplant shock. It gives the roots time to develop underground before the spring growing cycle.
How to Grow Katsura Trees From Seed
Katsura trees have the most significant growing success when grown from seeds. Collect seeds from fallen pods in the fall. Germination is almost 100% guaranteed when the seed pod has freshly fallen. Sow the seeds immediately indoors in nursery pots for best results.
If you get seeds from a nursery or another source, stratify them by putting them in a moist towel kept in the refrigerator for about eight days. Or, another method, expose the seeds to light for 15 hours a day for three weeks while kept moist on a paper towel.
Plant two to three seeds in a pot in moistened all-purpose soil or seedling mix about 1/4 inch deep. Cover the pot with clear plastic wrap to keep in moisture and promote germination. Put in a bright, indirectly lit place. Germination usually takes eight to 12 days. Let the plant grow for at least four to six weeks before transplanting into the ground or wait until the spring after the threat of frost is gone.
Protect young trunks from the winter sun by using a commercial-grade tree wrap around the sapling's trunk for the first few winters. Wrap it in the fall after its leaves have fallen and remove it in summer once the leaves grow back in.
Common Pests & Plant Diseases
This plant is relatively disease and pest-free. It may develop powdery mildew in very humid, warm climates. This mold looks like a light velvety white layer or white spots on leaves. Water at ground level at the trunk and along the drip line to prevent mold growth and take measures not to wet the leaves. You can remove and discard badly affected leaves or branches to reverse powdery mildew. Also, apply a fungicide, or for a natural remedy, spray a cow's milk solution over the affected plants (1 part milk to 4 parts water). Katsura trees are also deer resistant.
Common Problems With Katsura Trees
Katsura trees are hardy trees with very few issues that affect their growth. Picking a suitable planting site is perhaps the most essential factor for its health.
Browning Leaf Edges, Yellowing Leaves
If the leaf edges are turning brown and the center of the leaves are yellowing before the fall season, your tree may have leaf scorch. Dry weather, high winds, and exposure to too much sun can cause leaf scorch. You may notice the leaves falling in late summer rather than the fall. The placement of this tree is crucial in preventing leaf scorch; it can benefit from some shade from taller neighboring trees or wind protection provided by buildings or other trees. Watering your tree deeply and providing adequate mulching around your tree can also prevent leaf scorch from worsening.
Split Tree Bark
Bark can split from environmental stress due to temperature fluctuations, high winds, or excessive growth in autumn from too much fertilizer. Trim off the dead bark, but be careful not to pull off any remaining healthy bark. Water deeply but do not allow the soil to get soggy and apply organic wood-based mulch once every couple of years.
Sudden Tree Wilt
A stem canker caused by a fungal or water-mold infection can cause sudden tree wilt. The leaves will suddenly turn brown, start shriveling, and fall off. This infection is most likely from overwatering or too much rain or moisture. The condition may originate in the roots and root crown below the soil. At this advanced stage of deterioration, it may be difficult for the tree to survive. You can reduce watering, but nothing but time can say if your plant will rebound in the next growing season.
How long can Katsura trees live?
Katsura trees are very long-lived trees. Specimens planted in Europe and North America 1800s are still alive and growing strong. A Katsura tree in South America is over 500 years old. Since it has few pests and strong resilience, it can probably live over 1,000 years.
What trees are similar to Katsura trees?
The genus name of Cercidiphyllum indicates that the shape of the Katsura tree's leaves is reminiscent of the shape of the leaves on the redbud tree (Cercis genus). You can tell a redbud from a Katsura from how their leaves are arranged on the trees' branches: Katsura leaves line up in pairs directly across from each other, while redbud leaves are alternating.
Can Katsura trees be grown indoors?
Katsura can be trained to grow as bonsai plants. It's challenging and requires a cutting from a mature tree or starting from a seedling. A cutting from a mature tree is preferred since it can take decades to develop a trunk from a sapling. It will need shaping over time, adequate moisture, well-draining soil, and filtered sunlight to grow properly.