Wednesday, December 11, 2013

Eastern White Pine, Featured Plant of The Day

Pinus strobus 'Pumila'
White Pine,  Eastern White Pine

Type    Shrub, woody plant
Hardy range    3B to 7A
Height    8' to 15' / 2.40m to 4.60m
Spread    12' to 18' / 3.60m to 5.40m
Growth rate    Slow
Form    Oval and pyramidal
Exposure    Partial shade or partial sun to full sun
Persistence    Evergreen

Bloom Color    Pink and yellow
Bloom Time    Spring

Environment
This plant will grow in moist soil.
Suitable soil is well-drained/loamy or sandy.
The pH preference is an acidic to neutral (less than 6.8 to 7.2) soil.

Leaf Color    Blue and green
Fall Color    No change in fall color

Culture Notes
White pine is a traditional favorite in northern landscapes that grows well in situations mimicking its native habitat. Unfortunately, few urban sites match this criteria. Try to provide loose loamy, acidic, moist soil with adequate organic matter. Young White Pines are quite tolerant of half-day shade while mature White Pines prefer a sunny location. They grow poorly and develop chlorosis and die on clay soil. Sites with an alkaline pH also causes decline. Trees appear to have little tolerance for drought, soil compaction and heat. Eastern White Pine suffers from application of roadside deicing salts and is sensitive to air pollution, especially ozone and sulfur dioxide.

Trees are probably best suited for zone 6B and north. Trees transplant easily but allow plenty of open soil space for root development. Trees perform poorly in restricted soil spaces. Needles in fascicles of 5.

Like most pines, trees best recover from transplanting when moved balled and burlapped, not bare-root. They also grow fine when planted from containers provided plants are not root bound.

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.