Yeah, I'm anxious to know too.

Korina

hmmm, yes, some clarification would be nice.

My understanding is that many of the ones commonly grown prefer slightly alkaline soil (no doubt I'm totally generalizing), and yet in cultivation most common potting mixes are peat-based or sphagnum moss, both of which are slightly acid. I've heard it said that the airiness of the mix and the moisture level is more important to them than the pH (within a reasonable range).

My water comes from the high Sierras and is very pure, as it flows over high mountain granitic soils. It used to be on the acidic side, but now they add chemicals to raise the ph above 8. I haven't seen any particular problems.

I've just switched from Canadian sphagnum peat in my mix to Coir. So far so good, but its too early to tell. I have noticed that it is easier to wet the dry mix. There are a few long hairlike strings in the coir, but that is quite minor. The downside is the supplier is an hour away. I don't know how the coir will affect PH vrs peat.

Jon

my uneducated understanding is that coir is closer to ph neutral than peat. It also has a reputation for decomposing/compacting faster than peat, so I have been hesitant to use it. I did get some recently though, and am thinking of trying it on seedlings, which would get potted on frequently anyway.

I use coir for one year now and I can strongly recommend it...
It is actually very slow to decompost so it is much more stable than peat. It means it is not so urgent to repot my plants so often. Water retention is better and it is easy to water even bone dry plant - it sometimes happen, you know...it should not but it does....:-)
And it is environmentally friendly what is good too.
I guess everybody is little different and has different approach. Still - coir is very, very good base for soil mixes for all plants. At least that is my experience.
I think PH is quite important. My water has ph 8 - so I am adding some sulphuric acid or PH down powder and I definitely can see difference in plants, even in outdoor garden(try it on citruses). Everything looks more healthy, more green.
Again - it does not mean that everybody must use coir or learning water chemistry - it just happen that in my growing condition lowering ph made a big difference.
Happy growing!
Alena

The link is to Doctor Optimara. Useful stuff.

Korina

Here is a link that might be useful: PH imbalance

Thanks Korina. If the pH should be around 7.0 (within 0.2) then perhaps I need to find alternative water since the tap water here is quite alkaline (8+)

I appreciate the useful leads.

When my youngest was still home we got interested in tropical fish--he was going to grow the fish and I was going to grow the plants--and some of the fish needed acidic water. We learned that we could treat the water quite effectively by putting some peat in a large container and filling it with water, or in the case of one species of fish keeping a layer of peat on the bottom of the tank. The water was brown like well-brewed (over brewed?) tea, and the fish did very well. And then when I vacuumed the bottom of the tank the plants I watered with the cleanings did very well too. Now I save rainwater, which I think runs a little on the acid side at least here, tho' it varies. I suppose I ought to get serious about testing it again--water and soil, that is. Also I use crushed eggshells in my mixes a lot.

You have to remember that water is mostly, um, water. There isn't much in the way of solids in it. But, what solids are found, are what contribute to the ph. So, I really don't think that ph of water is a major factor in plant growth. Certainly though other factors in our water can have a heavy influence. Two that I know of, are salts and boron. These are both quite detrimental to plant growth. I know one woman who gardened on her former farm in Walnut Creek, Calif. She would try all kinds of plants and just not do well. Plants like rhododendrons, camelias etc. just didn't survive. Finally she had the water tested and discovered that her well water was high in boron. But, her succulents did well, so she switched to growing them. Now, her 5 acre succulent garden is part of the National Trust and is open to the public.

Jon

I think I'm going to switch to coir.

No -- no I'm *definitely* switching to coir.

From everything I've read my soil is too acid. Good thing I never took to watering with tea.

Korina

I must say in all my reading from numerous sources over the years I've never heard of a slightly alkaline potting mix being good or important for most gesneriads, and usually they're said to like just "slightly acid" to neutral soil. I've only grown African Violets and Episcias for the most part, and have never paid any attention to my pH, and have never had problems with most peat based potting mixes. It's quite possible that some types of gesneriads do prefer slightly alkaline soil as well, so I'll not say that all prefer the slightly acid to neutral mixes. My water is somewhat basic I believe , and I do have problems with other real acid loving plants however and a very difficult time getting those pH's adjusted so they really are acid enough for the acid loving plants. Could be the constant watering with alkaline water!!