Platycladus

( plat - ee - KLAD - us )

At-A-Glance Information

Commonly called Oriental Arborvitae, Biota, and Oriental Thuja and known under the alternative botanical name Thuja orientalis, this species of evergreen trees needs full sun (partial shade in warmer climates) and moderate to regular water. These trees are native to Korea, Manchuria and northern China, and reach 25 feet tall and 15 feet wide. The true species itself is rarely seen; its varietals are more commonly grown and available at nurseries. New leaves are needlelike, and mature to scale-type green or yellow-green leaves carried in sprays. Cones are gray-blue when new, and turn brown as they age on the plant. They produce a wonderful smell when crushed, and are used in potpourris. Great as formal shrubby trees near doorways or gates, and can form rows in formal gardens. Take care when planting these trees in the landscape, as plant parts are toxic to pets and can cause mild skin irritation in sensitive individuals.

platycladus species and Varietals

The genus Platycladus is a member of the plant family Cupressaceae, and includes just one species, Platycladus orientalis. The best growing zones for Oriental Arborvitae are 2-24, H1 and H2. To find your zone, click here: Zone Map.

'Aurea Nana'
(Dwarf Golden Arborvitae)
This variety has an upright, globular shape to 3 feet tall and 2 feet wide (hough it can reach 5 feet tall in some cases).

'Beverleyensis'
(Beverly Hills Arborvitae)
Upright and conical, with a slightly open habit. Tips of branches are golden-yellow, and these plants can reach 10 feet tall and just as wide. Best with regular waterings.

'Blue Cone'
This varietal is a dense, upright and conical shrubby tree to 8 feet tall and 4 feet wide.

'Bonita'
('Bonita Upright', 'Bonita Erecta')
A rounded, full, dense cone reaching 3 feet tall and 2 feet wide, with dark green foliage that is tinted gold at branch tips.

'Collen's Gold'
Narrow, upright variety reaching 8 feet tall and 4 feet wide, with bright yellow foliage.

'Elegantissima'
Upright and conical, to 15 feet tall and 6 feet wide. Golden-yellow foliage turns yellow-green in summertime, and takes on bronze tones in cooler weather.

'Fruitlandii'
(Fruitland Arborvitae)
A compact, upright shrub with deep green foliage.

'Minima Glauca'
(Dwarf Blue Arborvitae)
Reaches 3-4 feet tall and wide, with blue-green foliage.

'Raffles'
3 feet tall and 2 feet wide, with an upright-globe shape. Foliage is bright yellow-green.

'Westmont'
Reaches 3 feet tall and 2 feet wide. Green foliage, and yellow-tipped branches.

Caring for and pruning Platycladus Trees

Plant Platycladus trees in a place in the landscape that receives full sun to light shade. Full sun exposure will lead to denser, more prolific foliage growth, but in warm climates they appreciate some afternoon shade. Protect these trees from reflected light and intense heat. Ensure that soil is well-draining before planting; if local soils are compacted or overly clayey and do not drain well, make sure to amend the planting site with plenty of organic material before installing. If planting these trees as a privacy hedge or screening, space them between 6 and 10 feet apart (depending on the species grown) to allow for proper growth and to prevent overcrowding. 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. Newly planted trees should be watered regularly as they establish strong root systems. Established trees should also be watered regularly, especially in the drier, warmer months of the year.

These trees require little to no pruning. Simply remove damaged, diseased, or dead branches in late winter to early springtime. Avoid heavy prunings and cutting into old wood, as it is unlikely to push out new growth. Apply a dressing of organic compost in early springtime around the base of trees to provide nutrients for the growing season. They do not typically need much fertilizing, but if soil is particularly poor or if trees seem to be struggling, they may benefit from a feeding with a balanced, slow-release fertilizer applied in springtime. Avoid over-fertilizing Platycladus plants, as doing so can harm them.

Propagation

Platycladus 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 Caesalpinia, follow the instructions below:

Propagating Caesalpinia by Cutting

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.
In spring or early summertime, 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.
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.
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 Pinus by Seed

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.
Harvest your seeds. Seeds are contained inside of the female cones produced by trees in summer or fall. They are the larger cones on the trees (smaller cones are male, and do not contain seeds). Cones will fall from their attachments when mature, and can be picked off of the ground. Remove seeds from cones and then place them in a bowl with lukewarm water for about 15 minutes. Viable seeds will sink, and floaters can be discarded.
Pine seeds need to be cold-stratified to increase odds of germination. Place seeds in a sealable container or plastic bag filled with moistened sand or peat moss and place the container in the refrigerator for between 60 and 90 days. Then, remove them and lay them out to work with them.
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.
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.