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Caring for Azaleas and other Acid Loving Plants3/19/2013


 

Caring for Azaleas and other Acid Loving Plants

Acid-loving plants are very much a part of today’s landscape.  Some popular plants requiring a higher acid level in the soil include azalea, holly and rhododendron but by no means are they the only acid loving plants commonly found in the garden. 

A little about soil pH

Soil pH can be a critical factor in your gardening success.  Some plants thrive in neutral soil while other plants prefer a more acidic environment.  The difference lies in the plant’s ability to use nutrients present in the soil.  For plants that prefer a more acidic soil, a critical nutrient is iron.  Iron is most available in soil with a pH of around 5.5.  Without iron these plants will turn yellow and suffer stunted growth.

Lowering soil pH is not difficult. When planting an acid loving plant work in organic matter such as peat moss or compost.  For existing plantings, regular feeding with an acid based fertilizer such as Holly-tone will keep the soil at an optimum pH while providing all the major, minor and trace nutrients plants require.

Planting

When planting, remove one third of the soil taken from the hole and replace with compost, peat moss or humus.  Add one cup of Holly-tone per 2 ½ gallon bucket of soil – and mix thoroughly – use this soil to back fill your planting hole. 

Feeding

 

·         Spring: Feed acid loving plants in the spring with Holly-tone.  In general, the proper rate of application is one cup of Holly-tone per foot of branch spread.  This rate should be doubled for plants over three feet wide.  Do not work the plant food into the soil as some of these plants have surface root systems that  can be disturbed by such activity.  It is best to apply Holly-tone directly to the soil prior to mulching.  If this is not possible, apply double the standard rate above the mulch.  This will compensate for the loss of nutrients in the mulch layer.

·         Fall:  A second half-strength feeding of Holly-tone is recommended in late fall.  This will help harden off new growth, aid in root development, and enable the roots to store food for use in early spring.

Partial list of plants preferring acidic soil:

 


Amaryllis

Andromeda

Aster

Azalea

Bayberry

Bleeding heart

Blueberry

Camelia

Dogwood

Evergreens

Fern

Fir

Gardenia

Heath

Heather

Hemlock

Holly

Huckelberry

Hydrangea

Inkberry

Juniper

Leucothoe

Lily-of-the-Valley

Lupine

Magnolia

Marigold

Mountain-ash

Mountain-laurel

Oak

Pachysandra

Phlox

Pieris

Pine

Raspberry

Rhododendron

Spruce

Strawberry

Whitecedar

Woodsorel