Platanus

( PLAT - ah - nuss )

At-A-Glance Information

Commonly called Plantain Tree, Plane Tree or Sycamore, this genus of deciduous trees needs full sun and moderate to regular water. These trees will attract butterflies to your garden. Plane Trees are known for their shedding bark, their seed clusters that hang onto bare branches through the winter months, and their usefulness as street and shade trees. All members of the genus reach between 100 and 165 feet tall when mature (though are usually seen much smaller in gardens). All but one species in the genus are deciduous. Take care when planting these trees in the landscape, as some species can cause allergic reactions or skin irritation in sensitive individuals.

Platanus Species and Varietals

The genus Platanus is both the only living member and the type genus member of the plant family Platanaceae, and includes 12 species. The ideal growing zones for Platanus trees vary depending on the species grown. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Platanus x hispanica (Platanus x acerifolia) (London Plane Tree)
This species grows well in zones 2-24 and is a hybrid variety between Platanus occidentalis and Platanus orientalis. These trees quickly reach 40-80 feet tall and 30-40 feet wide, with good tolerance for smog, soot, dust, and reflected heat. This species is susceptible to mildew. Varieties include 'Bloodgood' (resistant to Anthracnose), 'Yarwood', (with good mildew resistance), 'Columbia' (resistant to both mildew and Anthracnose). Commonly grown 'Morton Circle' (also called 'Exclamation') is a great, upright grower to 50 feet tall and 30 feet wide, with a good resistance to Anthracnose.

Platanus kerrii (Kerr's Plane, Ma Nang, Cho Nuoc)
This species is native to Laos and Vietnam, and is quite different from other species. It is a tropical evergreen plant, but has the same flaking bark and appears similar in habit. The species was named for Arthur Kerr, who collected the type specimen while in Laos in 1932.

Platanus lindeniana (Platanus chiapensis, Platanus oaxacana) (Linden's Plane Tree, Linden's Sycamore)
​This species is endemic to eastern-central Mexico down through Guatemala, and prefers to grow in semi-arid and temperate climates. It was first described by Martin Martens and Henri Guillaume Galeotti in 1843. These trees reach 55 feet tall when mature on average when grown in landscapes.

Platanus mexicana (Mexican Sycamore)
This species of Plane Tree is native to Northeast and Central Mexico and Guatemala. It is deciduous, and foliage turns yellow in fall before leaves are shed. Trees can reach up to 80 feet tall.

Platanus occidentalis (American Sycamore, Buttonwood, Water Beech, American Planetree, Western Plane)
This species is best in zones 1-24 and is native to eastern areas of North America through the mountains of northeastern Mexico. These trees have irregular habits, and have been seen growing as a leaning tree and at times with multiple trunks. Best in large gardens where it has some space to spread if needed. Trees reach about 40-80 feet tall and 30-40 feet wide.

Platanus orientalis (Oriental Plane)
This species reaches up to 100 feet tall or more at maturity, and produces deep green leaves that turn colors in fall. These trees are native to Italy, the Balkans, Turkey, the Caucasus and Iran. These trees are grown as ornamentals in temperate latitudes, and benefit from warm summertime temperatures. 

​Platanus racemosa (California Sycamore, Western Sycamore, California Plane Tree, Aliso)
This species does well in zones 4-24, and is a hearty native of coastal California and the Coast Ranges. Trees reach 30-80 feet tall and 20-50 feet wide in a short amount of time. Bark is patchy and attractive, and leaves turn brown in fall. Can take heat and windy conditions. Good for large or informal gardens.

Platanus rzedowskii (Rzedowski's Plane Tree, Rzedowski's Sycamore, Sicomoro de la Sierra Madre Occidental, Sierra Madre Occidental Sycamore)
This species reaches 80 feet or more when mature, and produces olive-green foliage. Flowers are white, and bloom from December through February. Blooms are followed by rounded, spikey fruits that are present on the tree from April through August. These trees are mostly used as ornamentals.

​Platanus wriightii (Platanus racemosa wrightii) (Arizona Sycamore)
This species is best in zones 10-12 and is native to the canyons and streams in southern and eastern Arizona, New Mexico and Mexico. These trees are similar to California Sycamore, but with more deeply lobed leaves and strange-stemmed seed capsules. Mature trees reach about 80 feet tall.

Caring for and pruning platanus Trees

These popular urban landscape trees prefer to be planted in full sun, and ​do best when they receive at least 6 hours of direct sun each day. These trees need a good amount of space to accommodate their full size, which can be up to 70-100 feet tall and 60-75 feet wide; they are best in large parks or landscapes. Their roots can be a bit of a nuisance to surrounding hardscapes and other structures such as sewer pipes, walls and fences. Take care to plant these trees far from structures if possible. Ensure that soil is well-draining. If local soil is particularly clayey or has poor structure, amend the planting site with plenty of organic material and/or sand. Planetrees prefer soil to have a pH of between 6.0 and 7.0. Apply a thick layer of mulch around the base of trees to suppress weed growth, increase soil moisture retention, and help to regulate soil temperatures. Water newly planted trees regularly, ensuring that soil maintains a consistent level of moisture. Mature trees also appreciate consistent moisture, but can get by on rainwater alone for most of the year. Deep water established trees during the warmer, drier months of the year every week or two so that soil does not dry out completely. They are somewhat drought tolerant.

Platanus trees are best trimmed in late winter or early springtime, before new growth pushes out for the year. They don't need much in the way of pruning; simply remove dead, diseased, or damaged branches. Popular pruning techniques for London Planetree include pollarding and pleaching (braided into a fence). They also do not require frequent fertilizing; and will get by on applications of organic compost yearly in springtime. If they seem to be struggling or foliage is discolored, they may benefit from a feeding with a balanced, slow-release fertilizer applied in springtime. Do not over-fertilize these trees, as doing so will harm their health and open them up to pest and disease issues.

Propagation

Platanus trees can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your London Planetree, follow the instructions below:

Propagating Platanus by Cutting
  1. Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
  2. In spring, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
  3. Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
  4. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Platanus by Seed
  1. Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
  2. Harvest your seeds. Seeds are mature in fall, and their balls break open to release seeds in early wintertime. Seeds are small and covered in stiff hairs, allowing them to float through the air away from the parent tree. Harvest balls from trees in late fall or early winter, and place them in a paper bag. The seeds will release from their balls over the next few days, a process that can be helped along by shaking the bag from time to time. After they have been released, seeds can be stored in a cool, dark, dry area of the home or they can be sown. If sowing seeds, place them in a bowl of water for a few hours. Viable seeds will sink to the bottom, and any seeds that float can be discarded.
  3. In fall, water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
  4. Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.
Platanus trees produce seeds that are held in rounded clusters.
Platanus seeds have hairs on them that catch the wind and allow them to travel away from the tree,

Problems and Pests

These trees unfortunately can themselves be considered an issue. The large surface roots that Platanus trees have make it difficult sometimes to maintain concrete walkways or sidewalks nearby. Typically, Planetrees are rarely bothered by pests and disease, though they can be affected by the following issues from time to time:
  • ​Anthracnose
  • Canker Stain
  • Leaf Spot
  • Powdery Mildew
  • Borers
  • Scale Insects
  • Japanese Beetles
  • Caterpillars
  • Mites
For more information on these pests and diseases, consult the following pages:
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Gallery

The bark on these trees is beautiful, and peels away to reveal creamy whitish-green inner bark.
Platanus trees are very common in urban landscapes.
The foliage and flowers of a Platanus tree.
A grand entrance framed with London Planetrees at Filoli Gardens in Woodside, California.
London Planetree flowers are borne in rounded clusters, and are typically reddish.
These are common trees in urban settings and are frequently used as street trees.

Videos

Learn about these wonderful trees.
All about Platanus occidentalis.

Resources

Learn How to Plant Planetree Seeds
How to Grow and Care for London Planetree
Wikipedia: Platanus
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Pages 512 - 513, Platanus
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