Monday, May 5, 2014

'Strawberry Ice' Azalea: Featured Plant of The Day

 Rhododendron (subgenus Azalea) 'Strawberry Ice'
    Azalea


Type    Shrub, woody plant
Hardy range    5A to 9A
Height    4' to 7' / 1.20m to 2.20m
Spread    5' to 7' / 1.60m to 2.20m
Growth rate    Slow
Form    Rounded
Exposure    Partial shade or partial sun
Persistence    Deciduous

Bloom Color    Pink
Bloom Time    Spring

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
This plant has attractive fall colors.

Culture Notes
Partially shaded locations give good growth, provided drainage is adequate. Roots rot in soil that drains poorly. I (Dr. Gilman) have had no trouble transplanting 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 flowered for millennia 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.

Azaleas 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.

'Strawberry Ice' has deep pink blossoms with a yellow throat.

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.

Wednesday, April 30, 2014

Dwarf Crested Iris: Featured Plant of The Day


Iris cristata 'Alba'
Dwarf Crested Iris


Type    Perennial
Hardy range    5A to 9A
Height    6" to 12" / 15cm to 30cm
Growth rate    Fast
Form    Upright or erect
Exposure    Partial shade or partial sun to full sun


Bloom Color    White
Bloom Time    Spring

The flowers are 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
Iris cristata will spread quickly if it likes its location.






Tuesday, April 29, 2014

Black Root: Featured Plant of The Day

Veronicastrum virginicum 'Album'
    Black Root,  Bowman's Root,  Culver's Root


Type    Perennial
Hardy range    6A to 9B
Height    4' to 7' / 1.20m to 2.20m
Spread    36" to 4' / 90cm to 1.20m
Growth rate    Fast
Form    Upright or erect
Exposure    Full sun

Bloom Color    Lavender and white
Bloom Time    Summer

The flowers are suitable for cut flowers.

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

Leaf Color    Green

Culture Notes
Division of the clump can be done in the spring and stem cuttings can be taken in the summer. If plants are not grown in the full sun, they will need staking. Dead heading the spent flowers may encourage a longer blooming period. Seeds can be gathered and sown in the fall.  Plants serve as butterfly nectar sources.


Thursday, April 24, 2014

'Happy Wanderer' Vine Lilac: Featured Plant of The Day

Hardenbergia violacea 'Happy Wanderer'
    Vine Lilac,  Purple Coral Pea,  False Sarsaparilla


Type    Perennial, vine
Hardy range    9A to 11
Height    4' to 6' / 1.20m to 1.80m
Growth rate    Fast
Form    Prostrate
Exposure    Partial shade or partial sun to full sun
Persistence    Evergreen

Bloom Color    Purple
Bloom Time    Spring and Winter

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

Leaf Color    Green

Culture Notes
These vigorous climbers are grown for their attractive blossoms which appear in later winter and early spring.

Wednesday, April 23, 2014

Hydrangea macrophylla 'All Summer Beauty': Featured Plant of The Day

Hydrangea macrophylla 'All Summer Beauty'
syn. Hydrangea hortensis; Hydrangea opuloides 
Bigleaf Hydrangea, Florist's Hydrangea

Type Shrub, woody plant
Hardy range 5B to 9A
Height 4' to 6' / 1.20m to 1.80m
Spread 6' to 8' / 1.80m to 2.40m
Growth rate Average
Form Rounded
Exposure Full shade to partial sun

Bloom Color Blue and purple
Bloom Time Spring and Summer


Environment
This plant tolerates some drought, occasional wetness and some salt. This plant will grow in dry to occasionally wet 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 Green
Fall Color No change in fall color

The flowers are very showy.


Culture Notes
Since the deciduous Bigleaf Hydrangea blooms on large buds formed on previous season's growth, any pruning should be done immediately after flowering. Long popular as a florist's plant, Bigleaf Hydrangea performs well in moist, rich garden soil in partial sun to fairly deep shade, where it can grow 4 to 8 feet tall. Be sure that tree roots are not competing with the roots, since this will slow growth dramatically. Flowers are bluish in acid soil, pink in neutral. This plant is considered mostly allergy free and causes little or no allergy problems in most people.


Pests, Diseases and Damaging Agents
Pests: Aphids, four-lined plant bug, leaf tier, rose chafers, scales and mites can infest hydrangea.

Diseases: Bacterial wilt may blight the flower clusters and leaves. Bud or flower blight infects dense flower clusters in wet weather or after frost. Several genera of fungi cause leaf spots on Hydrangea. Powdery mildews in different genera cover the undersides of leaves with light gray mold. Rust causes rusty brown pustules on the leaves.