I have recently been told that many will grow a larger caudix and/or bulbous roots faster if they are planted low in the ground or in large pots with lots of root room. It was suggested that when they go dormant they should be removed from the ground and stored bare root to be planted in the ground again when they start to bud. I was told to do this until I achieved a size that satisfied me.
Was someone yanking my chain or is this valid advice? I know that Jatropha for instance like a shaded or protected caudix and full hot sun on the foliage. Thanks for whatever info. you can offer.
I think to apply that theory across the broad spectrum of caudiciforms is asking for trouble.
I wouldn't do large pots for Adenium, as too much soil will hold more water than the plant can absorb in a timely fashion, eventually leading to rot. I've found a pot to be about an inch larger in diameter than the caudex to be good on 9-12 month old Adeniums, while about 6-8" larger than the caudex is ideal on 8 year olds.
I don't have Adeniums. Well, a couple but they are not my thing. We were looking at my Bombax, Calibanus, Fockia, Cyphostomia, Pachypodium (lealii), Uncarina, Jatropha and others which I am growing for their caudex and roots. Some caudiciforms quite obviously could not benefit from being planted low in the ground. I am not going to bury my Pachy Lamerii's up to their growing tips. And all would eventually be raised to display their roots and/or caudex.
I think his point was that I could get faster growth if the foliage was given full hot sun. But since the caudex is sun sensitive and prefers shade, just bury it up to about the growth tip in the garden where it would also have a lot of root room. The idea of taking them out and storing them bare root was because I opined that winter temperatures in the garden might be too low.
Watering, drainage and rot is another issue which would have to be allowed for. Does anyone think this was good advice for some cauducforms and if so which ones? I think the advice was aimed at overcoming the contridiction of the foliage wanting full hot sun and the caudex being damaged by it. Thanks for whatever advice or experience you can offer. I certainly don't want to try something that more experienced hands say they tried and it failed.
Yes this is often done in CA and for many it works very well. The techniques requires control over water and lots of sunlight. I don't do it very often here in central Texas because spring/summer rainfall is unpredictable---we got 16" in June 2007 and less that 1" in June 2008. But in the reliably warm, dry, cloudless summer climate of So CA it works well---San Diego area in particular. Not only do the leaves get to photosynthesize to the max but the roots have full root run for exploration of soil resources and then storage of starchs and fluids.
In Philippe de Vosjoli's Pachycaul and Caudiciform Plants. A Guide to Growing, there is a nice discussion of this topic.
Never tried it myself but I can understand the concept. The biggest thing you would need to be careful of is that when you get ready to lift it, you should do it in increments and with caution.
Mine are all in full sun all day and do not have problems with sunburn. However, If I get a new one and want to lift it, I lift just a little at a time and watch how much sun it gets. The part that was in the soil IS suseptable to sunburn and must be accustomed to the sun.
I agree on watching your pot size. Oh, how many adeniums I have lost over the years until I got smarter. Invaribly, it was due to the plant being in a bigger pot which held the water for far too long.
Of interest, I do have two adeniums in semi hydroponics as an experiment, and they are doing well.
If you can control water and temperature, generally the more space the roots have the larger and faster the plant will grow. I put several plants known for their cool, twisting, caudiciform roots in a deep pot (and one in the ground) and their roots grew much larger than they were in my dinky pot I had them in before. The one in the ground grew so big I had to trim off some roots to get it back into a small pot. So next time I will just stick to growing them in deep pots, but about the same diameter as I want to transplant them back into, raising the roots way up.