Shop Products
Houzz Logo Print
ditnc

Planting medium for azaleas

ditnc
13 years ago

I planted 5 azaleas last week. We used the clay (dug from the holes), Black Kow (composted manure) and soil conditioner to fill the holes around and below the plants.

Today I bought a few more azaleas and the seller saw the Black Kow (composted cow manure) in my cargo hatch and said "watch out for using too much of that, it will burn the roots."

I have never heard of Black Kow burning before! To the contrary, I thought it was a very benign medium as long as it wasn't too dense, thus the soil conditioner.

Any thoughts or comments? I don't want to lose my azaleas. TIA

Comments (7)

  • Embothrium
    13 years ago

    Do not plant anything in amended holes dug out of clay soil. Return the same soil that came out of the hole to the hole, without adding anything except air (resulting from digging).

    If the existing soil it too heavy for azaleas buy suitable soil and dump that on top, planting in it without blending it with the existing soil.

    Rhododendrons and azaleas are built for low mineral content soils and can be damaged by salts that are not at all unsuitable for other kinds of plants not in the heath family.

  • rhodyman
    13 years ago

    People very seldom fertilize azaleas. Fertilizer can prevent them from blooming. They will usually have nice green leaves but no flowers. Too much fertilizer will cause burn which is characterized by the edges of the leaves becoming distorted and turning brown.

    Since azaleas need very good drainage, it is best to not plant them in holes in clay soil. The best alternative is to use raised beds. This means using a good acidic mineral soil with some conditioners such as sand, peat moss, perlite, and/or vermiculite in a raised bed over the clay soil. Then after planting, mulch thorough well to hold in the moisture and prevent weeds from growing. Azaleas have shallow roots so don't tolerate weeds, cultivating, or hot weather too well.

    Here is a link that might be useful: How to care for azaleas

  • ditnc
    Original Author
    13 years ago

    Rhody, by "fertilize", are you referring to my using Black Kow as a part of the planting medium along with clay and soil conditioner?

  • rhodyman
    13 years ago

    Yes. Fertilizing is any material with nitrogen, phosphorus and potassium like cow manure, Miracle Grow, etc. The nitrogen content is what does most of the damage. When fertilizing rhododendrons, it is best to use an organic fertilizer like HollyTone, but at very low rates. Chemical fertilizers destroy the mycorrhizae that make iron available to the plants.

  • ditnc
    Original Author
    13 years ago

    Thanks and "oh, crap!" I planted 5 with Black Kow mixed with clay and soil conditioner (little bits of bark I think).

    I didn't put any fertilizer in or around them. Hope they survive!

  • mori1
    13 years ago

    Actually, azaleas do quite well in clay soil. I have never amended the soil but every year after they are done blooming, I apply half of cup of aluminum or ammonium sulfate and that's it.

  • luis_pr
    13 years ago

    Hello, mori1. You may want to switch away from aluminum sulfate. It is not recommended for use around azaleas and rhodies (ok to use around hydrangeas though). In large quantities, it can cause problems.

Sponsored
Ed Ball Landscape Architecture
Average rating: 4.8 out of 5 stars30 Reviews
Exquisite Landscape Architecture & Design - “Best of Houzz" Winner