Cacti Without Soil

[Rockspeny]

Happy Sunday everyone,
For the first time this year I am trying "bare rooting" some of my plants for winter to ensure the roots are dry and reduce the chance of rot developing due to moisture remaining in the soil. Anyone else have exorience with this, and will my plants be OK laid open under newspaper for three months or so? I have been ro-rotating these plants to stop a flat spot developing.
This then got me thinking about growing cacti without soil, so the plants are in gravel or other inert media and the nutrients come from fertilizer provided with the waterings. This would be good for me because the roots would dry out quicker. Sunlight comes into my growing space at an unusual angle and the pots don't get warm enough for me to be confident they dry out at the bottom between waterings, only the top half does. I lost one plant last year due to rot starting this way and I consider it a lucky escape and I don't want to loose others this growing season. So, anyone with experience in this way of growing I would love to hear from you.
Thanks for reading.
Spen

[Bonsai2]

I am growing 90% of my Mesembs around 120 including Lithops, Conophytum, Gibbaeum, Faucaria, Cheiridopsis plus a few others in 100% 2-5 mm Pumice for the last 9 months and am very pleased with the results. I feed them monthly in their growing seasons only with Maxicrop seaweed plant growth stimulant at 1/4 strength. Many have flowered this year. I sowed Faucaria tuberculosa in 1-3mm Pumice last June and have just repotted them into 2-5 mm Pumice. The roots are 2.5 cm long and very healthy.

[Rockspeny]

Thanks Bonzai, I will try it out this year on some of my cacti and see how it works. I will look out for the fertilizer you have mentioned, for the two seasons I have been seriously growing I have been using Tomorite at 1/4 strength, twice a year towards the end of flowering so June and July time.

[Chris L]

I've switched to pumice. Plants seem much happier in my conditions.

Words of caution though. ALL the soil and old fine roots need removing before potting into pumice, and expect plant losses.

You'll know when it works as you'll be able to pick the pot up by the plant body and everything will stay in the pot.

[DaveW]

Cacti like most plants can be grown hydroponically in one form or another, the nutrients supplied in solution rather than from organic matter in the soil..

https://gardeningwithallie.com/can-cact ... oponically.

https://gardeningtips.in/growing-hydrop ... full-guide

https://www.hunker.com/13426578/how-to- ... oponically

https://www.youtube.com/watch?v=0uH_-IUxmQw

I remember reading decades ago before the Berlin Wall came down some in the East were not allowed coal to heat their greenhouses for growing exotics over winter. They used to unpot their cacti, wash all the soil off the roots and then provided they were fully dormant so they would not etiolate in the dark, wrap them up in newspaper and store them in their cellars over winter. Taking them out and unwrapping and replanting in the pots again the next growing season. Obviously they need to be fully dormant and kept cool so they do not start to grow and so etiolate in the dark.

[Rockspeny]

Thanks for that info DaveW, that last bit is very similar to what I have done with several of my larger plants although they are still in the "green shed" but wrapped in newspaper. I check on them each weekend and rotate then so they don't get a flat-spot and they seen fine. In March once there is no chance of hard frost I'll unwrap them so they can see the day length increasing and hopefully they'll pick up and produce roots as normal. The faster growing echinopsis and gymnos will be into soil, the slower ones into grit n pumice.

[ralphrmartin]

I've put some of my plants into pumice too, and they seem to mainly be doing OK. A word of warning though - if you put tiny seedlings straight into pumice, they will stay small for much longer than in regular compost. The danger of overwatering increases as plants get bigger and older, so I recommend pricking cactus seedlings out into ordinary compost, and then moving them into pumice the first time you repot.

[DaveW]

If you are growing hydroponically, semi-hydroponically or in a purely mineral compost you need a fertiliser that supplies all trace elements needed. Some general garden fertilisers rely on the plants extracting some nutrients or trace elements from the organic part of the soil. Therefore check the fertiliser you use contains required trace elements.

https://www.succulent-plant.com/fertiliser.html

[gerald]

I'd be interested to hear if anyone has tried growing in coco coir

[Herts Mike]

A couple of years ago I switched all my Stapeliads to cat litter and they did well but I found watering difficult and switched back.