Monday, February 6, 2012

Chinese Juniper, Evergreen Tree of The Day

Juniperus chinensis 'Sylvestris'
    Chinese Juniper,  Juniper

Type    Tree, woody plant
Hardy range    4A to 10A
Height    15' to 25' / 4.60m to 7.60m
Spread    6' to 10' / 1.80m to 3.00m
Growth rate    Average
Form    Oval and pyramidal
Exposure    Partial shade or partial sun to full sun
Persistence    Evergreen

Bloom Color    Brown and yellow
Bloom Time    Spring

Environment
This plant tolerates drought and salt well.
This plant will grow in very dry soil.
Suitable soil is well-drained/loamy, sandy or clay.
The pH preference is an acidic to alkaline (less than 6.8 to more than 7.7) soil.

Leaf Color    Green
Fall Color    No change in fall color
This plant has fragrant foliage.

Culture Notes
Sylvester Juniper grows 20- to 30-feet-tall in a wide, columnar habit.  Foliage is a beautiful, soft-looking medium-green, but is sharp to the touch.  It is a refined cultivar of Chinese Juniper suited for planting in most any landscape.  It should be planted more often.

This juniper is best used as a tall screen on a large-scale site in the full sun.  It can be planted along the border of a commercial or residential landscape to define the space or set the boundaries of the property.  Its dense grown in the sun makes it nicely suited for a screen.  It should be spaced about 6 feet for a quick screen.

Natural habitat is dry and windy with full sun exposure.  It looks best in an open site with no shade during the day.  This allows the foliage to dry quickly in the morning and helps prevent foliage disease from thinning the canopy.  A well-drained soil is essential for good growth.  Wet soil rots the roots and causes plant decline.  Junipers can be challenging to transplant in the landscape due to poor slow regeneration on cut roots. Plants tolerate high soil salt - up to 8 mmhos/cm.

Planting and establishing shrubs

The most common cause of young plant failure is planting too deep.  Plant the root ball no deeper than it was in the nursery.  In most instances, the root flare zone (point where the top-most root in the root ball originates from the trunk) should be located just above the landscape soil surface. Sometimes plants come from the nursery with soil over the root flare. If there is soil over this area, scrape it off.  The planting hole should be at least twice the width of the root ball, preferably wider.  In all but exceptional circumstances where the soil is very poor, there is no need to incorporate anything into the backfill soil except the loosened soil that came out of the planting hole.  Never place ANY soil over the root ball. If a row or grouping of plants is to be installed, excavating or loosening the soil in the entire bed and incorporating organic matter enhances root growth and establishment rate.

Weed suppression during establishment is essential.  Apply a 3-inch thick layer of mulch around the plant to help control weed growth.  Keep it at least 10 inches from the trunk.  If you apply it over the root ball, apply only a one or two inch layer.   This allows rainwater and air to easily enter the root ball and keeps the trunk dry.  Placing mulch against the trunk or applying too thick a layer above the root ball can kill the plant by oxygen starvation, death of bark, stem and root diseases, prevention of hardening off for winter, vole and other rodent damage to the trunk, keeping soil too wet, or repelling water.  Regular irrigation through the first growing season after planting encourages rapid root growth, which is essential for quick plant establishment.