Which topsoil should I find and use?

[DesertSun]

Hello and thank you for reading.
I am gathering the necessary ingredients for a custom soil mix to pot my cacti, as most of them are
still in their nursery peat soil (albeit bone dry). I have pumice, perlite, coarse sand, and some bags of commercial cactus soil mix. Next is the lava rocks and the topsoil.
But I have no idea what kind of topsoil is advisable to use. Should it be mountain top soil? We have a soil in Greece called cumarohoma, which is essentially mountain soil gathered from near arbutus trees.
Then there is common garden topsoil, which is very alkaline and clayish in the case of our garden.
Forest soil maybe, we have a lot of pine soil near us.
Any advice would be much appreciated!

[ElieEstephane]

No need to create such a sophisticated soil mix. The components you already have are more than enough.
See: http://cactiguide.com/article/?article=article8.php
I personally use 2 parts grit to 1 part compost (not potting soil, compost as in decayed organic material) and my plants see to do fine and grow very vigourously.
For low priority plants or plants in large containers i mix topsoil from the garden (clay soil) with sand and occasionally some grit and compost. A top soil i personally like was that from below cypress trees. I just remove the top layer of fresh leaves and use the part that has decayed leaves and soil and i mix it with sand. However, i only use this for low priority plants such as agave americana or aloe vera...

[DesertSun]

What a relief, thank you very much Elie! I will follow your advice and it's actually easy to find cypress tree soil here also! Much appreciated!

[ElieEstephane]

The reason people use topsoil is that it contains micronutrients sometimes unavailable in other soil components. Using fertilizer whith micronutrients (which is very cheap and readily available) will very easily solve this issue.
I wouldn't use the cypress soil for cacti and succulents since you already have commercial cactus soil. It breaks down after a long while but when that happens you will have a clay soil that stays wet for too long. A better mix would be 3 parts pumice, 1 part perlite, 1 part course sand and 2-3 parts cactus soil.

[DesertSun]

Oh, thanks, that is even better and easier!

[jp29]

Visit the following CactIGuide article relating to making your own soil mix:

http://www.cactiguide.com/article/?article=article8.php

Don’t make life too complicated. I think I have used about every soil mix that has been devised during my growing lifetime -- and I have found all those that were of coarse and gritty texture, thus providing excellent drainage and root aeration, consistently produced healthy and robust plants. I think most commercial high quality bagged potting soil (very low in peat) mixed equal parts with a porous ceramic (fired clay) soil conditioner such as Turface - or coarse perlite - will work just fine. Many years ago, Bob Diehl - one of the old Vista commercial growers - used to say that you could successfully grow cacti and succulents in ground-up automobile tires if you followed good watering and fertilizing techniques. While I think that is a whimsical stretch, his point is well taken.

[DesertSun]

In ground-up automobile tires, indeed! Point taken here @jp29, thank you for all the advice! You and Elie have been so helpful!

[DaveW]

Yes a friend of mine who is a good grower always says you can grow cacti in anything as long as you get the watering correct. Meaning as long as the roots don't stay wet too long they will pretty well exist in anything, as with growing on rocks in habitat or limestone where other plants will not grow.

Obviously they grow better in a decent soil, but being well drained is the main requirement. Of course climate plays a part, which is why there is no correct soil for everybody worldwide since if you are in a hot climate where the soil dries quickly you can use a more water retentive one, whereas in a cold damper climate you need one that drains quickly and dries out much faster.

[DesertSun]

@DaveW, omg, I am anxious over the watering issue, where to start. But I have started by reading a lot of threads in this forum and I guess only this and time and experience will help in that. I have to make my mistakes and learn from them (brrr, already shakin' lol). So, for now, after reading all of your advice, I must focus into making my soil mix well draining and gritty!
My balcony is going to be very hot in the summer, I must try to keep that in mind and find the golden line there.
Thank you so much!

[ElieEstephane]

My balcony is going to be very hot in the summer, I must try to keep that in mind and find the golden line there.

That's why i suggested 2-3 parts of commercial soil in the mix. It will not dry to fast this way.
As for watering, to be safe, start when night temperature are consistantly above 15 degrees. First water just a little and infrequently to wake plants up. Gradually increase watering until by late may early june the plants are fully up. At this time you should water as soon as the soil is completely dry. In my case of 2 parts grit 1 part compost, it needed 3 days max to be completely dry

[DesertSun]

Got it Elie, that sounds great!