Wednesday, May 22, 2013

Trail Blazer Rhododendron, Featured Plant of The Day

Rhododendron (subgenus Rhododendron) 'Trail Blazer'
    Rhododendron

Type    Shrub, woody plant
Hardy range    5B to 6A
Height    4' to 5' / 1.20m to 1.60m
Spread    4' to 5' / 1.20m to 1.60m
Growth rate    Fast
Form    Rounded
Exposure    Partial shade or partial sun
Persistence    Evergreen

Bloom Color    Pink
Bloom Time    Spring and Summer

The flowers are very showy.

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

Leaf Color    Green
Fall Color    No change in fall color

Culture Notes
Partially shaded location gives good growth, provided drainage is adequate. Roots rot in soil that drains poorly. I (Dr. Gilman) have had no trouble transplanting these plants balled in burlap, although many are grown in containers. Pinch back the flowers after they have faded to eliminate the brown developing fruit if you wish. However, this is not essential for good flowering the following year. After all, these plants have been flowering quite nicely without our intervention. This plant is considered mostly allergy free and causes little or no allergy problems in most people.  Organic amendments in the backfill help establish plants quickly by encouraging roots to grow out of the container and into backfill soil.

Rhododendrons are ornamental, ericaceous, broad-leaved evergreens.  Azaleas belong to this genus, but many are not evergreen.  They grow best in shade or partial shade.  A south or southwest exposure increases the chance of winter injury to evergreen types when grown in northern climates.  Plant in an acidic, moist, well-drained soil with a pH between 4.5 and 6.5.  Transplanting balled and burlapped or potted plants is most successful.  The shallow root systems are easily injured by deep cultivation, but benefit from mulching.

Plants fail to absorb iron and have yellow leaves with green veins if the soil is not sufficiently acidic.  Finely ground sulphur can be added to the soil to increase acidity.  Have the soil tested before planting in order to determine the pH. Apply a 2:1:1 N:P:K ratio fertilizer two or three times each year before and after blooming and perhaps again as plants enter dormancy - timing is not as critical as previously believed.   Prevent winter burn in northern climates by avoiding exposed planting sites and by shading during winter.

'Trail Blazer' has a vigorous growth pattern and sports light pink blossoms with deep red, center blotches.

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.

Tuesday, May 21, 2013

Blue Oat Grass Featured Plant of The Day


Helictotrichon sempervirens
syn. Avena sempervirens
    Blue Oat Grass,  Blue Oatgrass

Type    Annual, perennial, grass
Height    18" to 30" / 45cm to 75cm
Spread    12" to 30" / 30cm to 75cm
Growth rate    Slow
Form    Rounded
Exposure    Partial shade or partial sun to full sun
Persistence    Deciduous and evergreen

Bloom Color    Brown
Bloom Time    Summer

The flowers are showy.

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

Leaf Color    Blue, green and silvery
Fall Color    Brown and copper
This plant has attractive foliage and attractive fall colors.


Culture Notes
Blue Oat Grass is attractive as a single accent plant in a very small garden, or it can be massed in groups for a beautiful, fine-textured drift.  Blue Oat Grass prefers a full sun exposure, but will tolerate light shade.  It prefers a moist soil that is well-drained; however it will tolerate sandy as well as heavy clay soils as long as water does not sit on the soil surface.  If planted in heavy clay soil, this grass is prone to root rot.

Plant about 2 feet apart to form a solid mass of fine-textured foliage or in groups in front of a shrub border or in a row along a walk.

Blue Oat Grass has attractive thin gray-green, or blue leaves.  Leaf blades grow to about 12 inches long, are 1/2 inch wide and taper to a fine point.  Plants grow 18 to 30 inches tall.  The glaucous foliage provides a welcomed contrast to a green border.  Beige terminal panicles are produced in June through August, maturing to a light brown by the fall when they break apart and fall from the plant.  Attractive, light brown, fall foliage color persists throughout the winter.

No more than yearly fertilization is needed to keep plants healthy, and they should last for many years.

Monday, May 20, 2013

Windsor Rose Bearded Iris

Iris germanica 'Windsor Rose'
    Bearded Iris,  Tall Bearded German Iris,  Orris Root


Type    Perennial
Hardy range    4A to 10A
Height    18" to 30" / 45cm to 75cm
Growth rate    Average
Form    Upright or erect
Exposure    Full sun


Bloom Color    Pink
Bloom Time    Spring

The flowers are fragrant and suitable for cut flowers.


Environment
This plant will grow in moist soil.
Suitable soil is well-drained/loamy.
The pH preference is  a neutral soil.


Leaf Color    Green

Culture Notes
Prefers a sunny well-drained fertile soil.  Will tolerate some shade in well-drained areas.  Division can be done in the fall as well as early spring before new growth. The Orris Root can be dried and used in potpourris and other mixtures needing a lavender scent.



Paul's Glory Hosta, Featured Plant of The Day


Hosta x 'Paul's Glory'
    Hosta,  Plantain Lily,  Plantain Lily


Type    Perennial
Hardy range    3A to 8A
Height    18" to 24" / 45cm to 60cm
Spread    36" to 4' / 90cm to 1.20m
Growth rate    Average
Form    Rounded
Exposure    Full shade to partial sun
Persistence    Deciduous

Bloom Color    Lavender
Bloom Time    Summer

The flowers are showy and suitable for cut flowers.

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

Leaf Color    Blue, green, variegated and yellow
This plant has attractive foliage.

Culture Notes
Remove flower heads when flowers are spent.  Hostas will grow best in a moist, fertile loamy soil in a woodland setting.  Plants go well with: Astilbe, Ferns, Epimedium, Rodgersia, and Dicentra sp. This plant is considered mostly allergy free and causes little or no allergy problems in most people.

'Paul's Glory' has yellow foliage with a blue-green edge.   A medium-size hosta, it has bell-shaped blooms which top 2" scapes.  Its leaves are thicker than most hostas, making it less prone to slug attack and other pests.  Deer and rabbits are, however, attracted to 'Paul's Glory'.  There should be a reduction in nitrogen in late summer so as to allow the plant to get ready for fall dormancy.  'Paul's Glory' was selected by the American Hosta Growers Association in 1999 for its outstanding merits.

Tuesday, May 14, 2013

Hachmann's Erato Rhododendron

Rhododendron (subgenus Rhododendron) 'Hachmann's Erato'
    Rhododendron

Type    Shrub, woody plant
Hardy range    5B to 8B
Height    4' to 5' / 1.20m to 1.60m
Spread    4' to 5' / 1.20m to 1.60m
Growth rate    Slow
Form    Rounded
Exposure    Partial shade or partial sun
Persistence    Evergreen

Bloom Color    Red
Bloom Time    Spring and Summer

The flowers are very showy.

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

Leaf Color    Green
Fall Color    No change in fall color

Culture Notes
Partially shaded location gives good growth, provided drainage is adequate. Roots rot in soil that drains poorly. I (Dr. Gilman) have had no trouble transplanting these plants balled in burlap, although many are grown in containers. Pinch back the flowers after they have faded to eliminate the brown developing fruit if you wish. However, this is not essential for good flowering the following year. After all, these plants have been flowering quite nicely without our intervention. This plant is considered mostly allergy free and causes little or no allergy problems in most people.  Organic amendments in the backfill help establish plants quickly by encouraging roots to grow out of the container and into backfill soil.

Rhododendrons are ornamental, ericaceous, broad-leaved evergreens.  Azaleas belong to this genus, but many are not evergreen.  They grow best in shade or partial shade.  A south or southwest exposure increases the chance of winter injury to evergreen types when grown in northern climates.  Plant in an acidic, moist, well-drained soil with a pH between 4.5 and 6.5.  Transplanting balled and burlapped or potted plants is most successful.  The shallow root systems are easily injured by deep cultivation, but benefit from mulching.

Plants fail to absorb iron and have yellow leaves with green veins if the soil is not sufficiently acidic.  Finely ground sulphur can be added to the soil to increase acidity.  Have the soil tested before planting in order to determine the pH. Apply a 2:1:1 N:P:K ratio fertilizer two or three times each year before and after blooming and perhaps again as plants enter dormancy - timing is not as critical as previously believed.   Prevent winter burn in northern climates by avoiding exposed planting sites and by shading during winter.

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.