Notes From WRRC - Soil Mixes and Fertilizer

2013 Western Regional Rhododendron Conference, American Rhododendron Society

Newport, OR Sept 27-29

Recipes for various soil mixes used when growing rhododendrons.

Cuttings (from Terry):
40% fine fir bark
40% pumice
10% sharp mason sand
10% peat (Terry doesn't actually like using peat, try adding more of other ingredients, or try something similar)

Air Layering (from John Hammond):
1 part chopped up sphagnum moss
2 parts fine chopped bark

Transplant cuttings to pots (From Terry):
Fir bark mixed with zeolite (kitty litter). Zeolite gives something for the fertilizer to cling to.
25 lbs zeolite to 1 cuyd bark
Fertilize with Apex one year slow release 20-4-7 +iron, add epsom salt too.

Planting into Garden (From Species Foundation):
50% beauty bark
25% bark nuggets
25% rubber bark (porous lava rock about the size of bark nuggets)

Fertilize established plants in Feb-March
Apex 21-7-6, cool weather special, better for cooler climates