Showing posts with label acidic soil. Show all posts
Showing posts with label acidic soil. Show all posts

Saturday, February 1, 2020

Silberlocke Korean Fir


Dwarf cultivars of Korean firs (Abies koreana) are favorites among many conifer collectors (USDA hardiness zones 5-8). Four ultra-dwarf varieties grow inches per year. Horstmann’s Silberlocke’ is the leading Korean fir variety among conifer collectors. To encourage a deep extensive root system, extra care (TLC) is needed the first 2-3 years after planting in the garden.



Abies koreana  'Horstmann’s Silberlocke’
'Horstmann’s Silberlocke’ The German word silberlocke means "silver locks of hair". The needles on the branches curl on the tops exposing the white underside of the needles, resulting in a frosted look. Annual growth rate is 6 - 8 inches (15 – 20 cm). Over the years, 'Horstmann's Silberlocke' will develop into a small 12 feet high x 8 feet wide landscape tree. The curling needle trait is often lost as the plant age. ‘Silberlocke’ also produces purple/tan cones on young plants.

Plant in a humus-rich, acidic, well-drained soil and in a sun to partial shade garden bed. Mulch with acidic organic compost such as pine needles, shredded pine bark, or chips. Irrigate once or twice monthly during periods of drought, heat or high winds.


Korean fir appears to be more heat tolerant than other firs, but it prefers cooler regions of the U.S. As with most firs in the South, Korean fir will often fail if too hot and will fail in wet soppy soils. In the warm humid southeastern U.S. environment, Korean fir should be grafted on Momi fir (Abies firma) rootstock. Dwarf forms make great additions to a small urban garden, a rockery, or a large container. Korean fir is rated as deer resistant.


Because of their rates of growth, super dwarfs are investments in the future. A plant with some size will likely command a premium price.

Friday, June 18, 2010

New Hardier Gardenias

Old fashioned gardenias or cape jasmines (Gardenia jasminoides) are reliably hardy in USDA zones 7-b and 8. Plants require immediate protection when the outdoor temperatures dip below 15 to 20 degrees.

The new hardier cultivars are compact growers, 2-4 feet tall and 3-4 feet wide. ‘Frost Proof’, Crown Jewel™, and Heaven Scent™ are three promising hardy cultivars to try in USDA zone 7-a. All three strut great thick, high gloss, dark green foliage.

Choose a garden location with good air circulation. Morning sunlight and afternoon shade is the rule. Plant gardenias in a well-drained acidic soil, and generously amended with compost. Water plants when dry and never overwater them. Acute leaf drop occurs in poorly drained soil. Fertilize once a year after the heaviest blooming cycle in June has past.

Fully capture gardenia's fragrance by planting in a garden spot or a container nearby a deck or patio. Individual blossoms generally last a few days. Flower loss may be rapid following a wind and rain storm.

Prune gardenias is immediately after blooming in early July. Remove all dead or unsightly shoots anytime you see them. Additional scattered blooms may occur anytime during the growing season. Late pruning should be avoided in the fall as next year's flower buds are being set.

White flies and flower thrips are major nemesis of gardenias. Bayer Advanced Tree and Shrub™ (soil drench) and horticultural oil (spray) should clean up most pest problems. Always read the pesticide label before using!