What about using Ph lowering fluids that one uses in ponds ? We use Ph- in our koi pond. Who knows, it might be usable for lowering Ph in soil.

Do you know what it is made of?

It is 100% biological. The brand we use is 'Perfect Pond'. It's a Belgian manufacturer.

Product info:
100 ml PH- lowers the PH of 1000 liter pondwater with 0,5°

website: www.perfect-pond.com

I do not know wether or not it could be helpfull. I don't know if lowering the PH of the water will result in a lower PH of the soil. Also this product is pretty expensive (if I'm not mistaken). Could be 50 euro for a bottle. Though that treats about 5000l of water.

Edit: last part was completely wrong. Don't know where I got that idea. Deleted it !

This week I have been discussing soil type with the fertilizer manufacturer. He suggested to use a different type of soil after hearing I'm using DCM Mediterra. He had heard complaints from people that the DCM soil stays too wet for too long and he suggested to contact a potting soil manufacturer for a better soil type.

So I did, and I managed to get a free 50 litres bag as a sample. The new soil contains perlite, osmocote, cow manure, peat etc... I'll check the bag later for the correct composition. It's too hot now outside! 30°C/86°F... ok not as hot as what some of you guys/gals get but plenty warm for me, and the next couple of days wil be even hotter...

I did some repotting (or better - resoiling) this morning and found that some of the plants that aren't doing very well suffer from root rot! The most severe case of root rot I have found on my bergamot tree. In fact I'm really surprised that the tree is still alive!

So no more DCM Mediterra soil for me. I still have to find out how the new soil (Verta Buxus) will do.

Though it sounds good it does contain clay which holds a lot of water.

True, for now I'm not convinced yet. I think I will stay with the Ecostyle soil I also tried recently. It can hold quite a bit of water also but dries out much faster and has a very loose structure.

I decided to change the soil of the plants that were planted in the Verta Buxus soil again, and took the chance to make some pictures of the roots of my bergamot plant:

The whole plant : not a lot of roots left...


The roots : these are still alive. I do hope the plant will grow new roots.


With this small amount of roots it is impossible to keep the plant straight up without supports.

Reminder: it is pH, not Ph, ph or PH.

I have been growing citrus for many years but haven't yet found a perfect soil.
For the past six or seven years, I have been using a mix of coconut husk chips and peat. This was based on Millet's recommendations in this forum. I have found this works quite well for a couple of years, but any longer breaks down completely and roots die. With well over 100 pots I need something that lasts longer.
I have changed over to a gritty mix based on Cat Litter - not just any cat litter but one using fired clay granules. See the website
http://www.bonsai4me.com/Basics/Basicscatlitter.htm
I use 2 parts by volume of this, together with one each of perlite, coarse bark chips and a fine granite gravel. This creates a very free draining mix but with no nutrients, so I add slow release fertliser granules and always water with diluted soluble feed. I'm almost convinced, but not quite yet. Seedlings and very small plants don't like it, but most other citrus plants seem to thrive. I've continued to have a few that died, but it may just be the result of the previous wet mixture followed by the shock of re-potting.
If you want to experiment with something completely different from any commercial mix, you should give it a try!

Mike, I agree the Gritty mix is both slow to break down, and provides good drainage, I have tried it. The problem I had with the gritty mix was the sheer weight of the medium, especially for growers who wish to grow larger size trees, thus needing to transplant into larger containers. As the container size increases, it became so heavy it was not easy to handle, or move. However, for smaller size trees, it seemed to work OK, except for very small seedling. - Millet

Thanks for the info. Doesn't this kind of medium require a LOT of watering?

It certainly needs regular watering in warm conditions. That is the result of the free draining, and not having a wet compost water reserve at the bottom of the pot. But both the clay granules and the perlite absorb and then release water to the roots, so it's not so bad as you might first assume.