I am about to repot an old friend of a Peyote plant and wanted some expert guidance to avoid killing it. I couldn't find any info on the Nexus, but found a detailed but concise guide from crazycacti.co.uk. I thought some others may find it useful, so here it is:

When To Re-pot Lophophora?

Rare Cacti such as Peyote have evolved to withstand the harshest of conditions. It's not uncommon to see an old lophophora or ariocarpus cactus in the most denuded soil and toughest conditions flowering freely. Some say that the plant knows when conditions are tough and so chooses this time to flower and produce seed, hence giving itself; via progeny , the chance of survival. Knowing when to re-pot is something to learn through experience but if you want your plants to grow actively re-potting every one or two years seems sensible. If, on the other hand, you live a hectic lifestyle and are away from your plants a lot you might want to consider leaving them in their nutrient denuded soil. Plants in general are susceptible to shock and cacti are not different hence re-potted plants need careful vigilance for a month or so after re-potting to ensure that they are happy in their new soil.

If you want to re pot your collectible cacti bought from Crazycacti or elsewhere then follow these easy steps. Soils mixes and suggested ratios of loam to sand and other soil additives will be dealt with separately. For the purposes of this re-potting a Lophophora Williamsii Caespitosa has been chosen as an example. For soil John Innes No. 2 mixed with sharp sand and vermiculite has been used.

1.Select the rare cacti to be re-potted and a slightly larger pot perhaps offering 25% extra space. Don't go too big or your plant will run the risk of not being able to fill the surrounding space before that soil is leached by watering. Notice how the plant below has distorted the pot by its growth.

2. Make sure your selected pot is clean and free of pests and old soil. Place a good layer of sharp gravel or small pebbles in the bottom of the pot for drainage and circulation of air (Roots need air to grow healthily).

3. Mix preferred soil in an appropriate tray or bucket. In this case John Inns no.2, sharp sand and vermiculite.

4. Carefully remove cacti from old pot. Lift away as much old soil has you can without breaking the tiny system of roots attached to the main tap root. This is a good time to check for pests such as Mealy bug.

5. Fill the new pot with new soil to a height that allows the plant to sit a centimetre of so from the rim of the pot. Rember that soil will settle and subside over time so dont set it too low. Different cacti enthusiasts have conflicting views as to the appropriate height as in the wild plant such as lophophora will burrow into the gound during drought. I prefer to see my plants sitting above the soil. Whatever works for you...

6. Once happy with the height of the plant fill the surrounding space with soil and firm down around it just enough to ensure the plant is well supported.

7. Top dress with stones as this stops the soil drying out too fast.

Important- do not water straight away. If your normal regime is once a week leave it for two weeks before watering, longer to be safe. This is because the new soil will already have some moisture and will be full of nutrients. If you have damage any roots they might find it hard to absorb moisture for a while. A sudden increase in water and food can cause cacti to split, rot or even die.

Gradually increase watering to normal levels once you are confident that your rare cacti has settled in.

If you have lots of plants date the re-potting to give you an idea of when next to re-pot although if all goes well your plant will tell you soon enough when it takes up all available space.

Remember to re-pot late spring to mid summer, any time after that it is advisable to wait till the following year- your plant wont mind.

Job Done

So I finished my repotting and hopefully all went well. I made my own excellent growing medium for the job, with really good drainage and slow release feeds which these cacti need. It is pretty satisfying to do, and most of the main brand composts that you can buy from garden centres are pretty crap. Proper specialist mixes are stupidly expensive for hardly any compost.

My mix was approx (by volume):

40% John Innes No.2 Compost (use JI no.1 or JI seed if you have very young cacti, as these have less nutrients)
25% Horticultural Sand
15% Horticultural Grit (also used for top dressing)
20% Perlite

If you can't get John Innes no.2 or would prefer to make your own it consists of:
60% Loam
25% Peat
15% Sand
and then with each 10L of mix, add
6g ground limestone
24g bonemeal
24g superphosphate
12g potassium sulphate

Nice post! It is obvious that you take time and care to look after your peyote

How big/old is your cactus?

I also have a peyote which I bought about 3 months ago and it is about 4/5cm in diameter. The pot it is in is about 10cm in diameter and looks ok for now. I know it varies on initial pot size but what size did your peyote grow to before you re potted it?

Thanks

Hey thanks delta-9! I do have a bit of an obsession with them at the moment, I'm an avid collector! The big one I have is at least 20 years old, I bought it 10 years ago (ish) and it was around 10 years old when I bought it. It is about 9cm across now, with one 3-4 cm pup growing from the side. I'll post a picture up in this thread when I get a chance, it's lovely

The pot is maybe 20cm across, but twice as deep as the last pot it was in. The roots had become bound into the drainage stones at the bottom of the old pot, so they won't have been getting as many nutrients as they could have been. I'm would imagine the pot you have is fine. Once they are settled (which can take months) they seem fairly hardy.

I have lost a couple I grew from seed from the mother plant due to over watering. The roots rot if they are constantly damp, and you can't see the damage you are doing until it is too late. Less is definately more for slow growing cacti.

Interestingly, they will survive if the soil is flooded for quite some time. Apparently this is because they need contact with water and air to start to rot. I wouldn't test this theory out though!

Happy growing!!