Diatomaceous earth and azaleas

[Tink32]

I just have a quick question... does anyone know if it is safe to plant azaleas in diatomaceous earth? I appreciate any insight

 

[irene_b]

The question is why plant it in this?

 

[rockm]

Absolutely not. Diatomaceous earth is made up of fossilized sea creatures (which have high carbonate content). It is neutral to alkaline pH.

Azaleas are acid-loving plants, requiring acid pH. Planting them in this stuff would probably kill them.

Straight diatomaceous earth really has no role as a bonsai soil. It's simply not functional as such.

 

[irene_b]

I use it to kill bugs...

 

[Alain BERTRAND]

Diatomae are algae whose cell wall is made of silica. It is thus neutral to acidic with low buffer capacity, and safe to grow azaleas inside provided that particle size is OK and (because of the low buffer capacity) your water is not hard or that you have something to compensate for alcalinity from the water (acidic fertilizer or peat for example).

 

[Tink32]

The question is why plant it in this?

I frequent the website of Harry Harrington, bonsai4me.com, and there's an article on using cat litter as an alternative to more expensive bonsai soils. some cat litter is 100% diatomaceous earth. It is very absorbent and fast draining. I have other trees planted in this "soil" and have suffered no deaths, and I know that azaleas prefer acidic soil, i just wasn't sure if it would have any adverse affects on the plant itself.

 

[Tink32]

Absolutely not. Diatomaceous earth is made up of fossilized sea creatures (which have high carbonate content). It is neutral to alkaline pH.

Azaleas are acid-loving plants, requiring acid pH. Planting them in this stuff would probably kill them.

Straight diatomaceous earth really has no role as a bonsai soil. It's simply not functional as such.

That was one of my concerns, its high carbonate content

 

[Tink32]

I use it to kill bugs...

I have used it to kill an aphid infestation on my ivy plants

 

[Tink32]

Diatomae are algae whose cell wall is made of silica. It is thus neutral to acidic with low buffer capacity, and safe to grow azaleas inside provided that particle size is OK and (because of the low buffer capacity) your water is not hard or that you have something to compensate for alcalinity from the water (acidic fertilizer or peat for example).

That's good to know The particles are of good size, I don't have hard water in my area and the water is usually neutral(7 to 7.2) I also use an acidic fertilizer. Would you suggest I mix some peat in with the soil?

 

[Shima]

I think he means Diatomite, an excellent growing medium.

 

[Alain BERTRAND]

Would you suggest I mix some peat in with the soil?

I personally do because to increase water retention.

 

[Bill S]

Suthin says that if it is planted in kanuma, find more to repot it, if it is not, then use acadama, and peat.

 

[Tink32]

I personally do because to increase water retention.

that works for me, but I do have another question, do you think pine bark would work? I know that peat is slightly acidic, i would assume pine bark is too.

 

[Tink32]

Suthin says that if it is planted in kanuma, find more to repot it, if it is not, then use acadama, and peat.

its actually still in its nursery pot with regular potting soil, I planned on using akadama if D.E. wasnt going to benefit my tree, but I wouldnt have thought to put peat in as well. thank you for the feedback

 

[BonsaiRic]

I've used a combo of calcined D.E. and pine bark "fines" for the past 3 growing seasons and have great looking trees. Calcined D.E. from Napa auto parts store. I use a 1:1 ratio.

 

[Tink32]

I've used a combo of calcined D.E. and pine bark "fines" for the past 3 growing seasons and have great looking trees. Calcined D.E. from Napa auto parts store. I use a 1:1 ratio.

Ive been using the same stuff from Napa auto parts, I planted my mugo pine in a mixture of D.E. and pine bark about 3 months ago and the tree is doing fine.I used a 2:1 ratio though. I have a free supply of pine bark as I have a wooded area behind my house with a couple of fallen pine trees. Im glad to know that there is someone else out there that uses D.E. Am I to understand that you have azaleas planted in this medium?

 

[BonsaiRic]

Ive been using the same stuff from Napa auto parts, I planted my mugo pine in a mixture of D.E. and pine bark about 3 months ago and the tree is doing fine.I used a 2:1 ratio though. I have a free supply of pine bark as I have a wooded area behind my house with a couple of fallen pine trees. Im glad to know that there is someone else out there that uses D.E. Am I to understand that you have azaleas planted in this medium?

I have 3 nursery azaleas and one large collected azalea stump in this mix. Great growth, leaf color and health.

 

[Tink32]

I have 3 nursery azaleas and one large collected azalea stump in this mix. Great growth, leaf color and health.

Very nice! I appreciate the words of wisdom and look forward to repotting mine in the spring, thank you

 

[Bill S]

The typical chemical composition of diatomaceous earth is 86% silica, 5% sodium, 3% magnesium and 2% iron, bet that magnesium % has something to do with the greenery Ric, the silica isn't an issue, don't know about the salt content though. Can't imagine this breaks down to solution very easily so it should be alright.