Conophytums: split or pot on?

[Ali Baba]

I have a small but nice collection of Conophytum, about half of which came from Chris R in the days when he sold plants, and the others I have grown from Mesa Garden and MSG seed. I have noticed over the years that whilst some are happy to grow into large (for Conos) clumps, a few tend to falter and parts of the clump die off during the resting season. There are no obvious pest or rot problems to account for this so I assume it is a question of cultivation.
Those that have behaved badly have therefore been rejuvenated from cuttings.
Most of my Conos are in 2 inch square pots and comfortably fit, but a few are bursting over the edges and are clearly crying out for a bit more room next year.
My question is, are the badly behaved ones trying to tell me they need a repot, or is this inevitable occasionally with some species?

[BrianMc]

I think it depends on the species. Some species seem to be happy and keep growing and eventually form large clumps where as others begin to look tired and if not broken up and rerooted, will eventually start to die back as the stems lose their vitality. I found that most of the Conos I have grown will easily fill a 2" pot and be quite happy filling a 2.75" pot, but many of the smaller bodied plants will begin to struggle to get past their 3.5" pots. Some of the faster easier plants like C.meyeri and some of the bilobums can fill pans upwards of 5 -7 "

Perhaps others have a different experience.

Climate will have a lot to do with it too. On Facebook I have seen the plants of an excellent grower in Spain who grows massive clumps of everything and they look pristine.

[Terry S.]

If the plants are bigger than the pots, then get them potted into larger ones - I have done this in the past up till the end of this month, but much later and they will not have time to settle in before their summer rest. Most clustering conos should easily get up to the 8cm pot stage or larger.

Conos kept in the same pots for a long time will reach a steady state with only one new head per stem each year. Repot frequently and they will keep dividing and produce larger clusters.

Die back is usually the product of sunburn and is nearly always on the south or SW facing sides of the plants. it is also sometimes a sign of old age when the plants develop long stems with reduced water and nutrient transfer.

[Ali Baba]

Thanks both, I will repot the ones that are overflowing and see how they do. The pattern of dieback doesn't really fit with sunburn in my plants, its more sporadic and seems to be related to age. In any case my conos all go under the bench for the summer, where they get some late afternoon sun but are otherwise shaded and cool.

[ChrisR]

I think a lot depends on how much space you have. Personally I get as much or more pleasure from a 2" pot than with anything larger and I know I can accommodate many more plants in the same space. A 10" pan may look impressive but mostly every head looks the same as on a cluster in a 2" pot. So I break up my clusters on a regular basis which gives me lots to share, keeps the plants more vigorous and plenty of room for a more comprehensive collection.

[Ali Baba]

That’s a good point Chris and generally after my own heart, I rather like the fact that my entire Cono collection fits neatly into a couple of seed trays. Rooting cuttings seems very easy and the resulting plants always seem to grow more vigorously. I suspect I will repot a few to see how they fare and also take cuttings from around the edges to replace the big ones if they outgrow their welcome

[el48tel]

You guys are making me want to grow some.
So if I grow from seed .... when is the best time to plant? At what temperature, heated propagation tray or cool GH? What Compost type? Gritty or organic?

[NickHitchcock]

I got my first ones from last years seedlist and planted them at the end of September, same compost mix as I have for cactus. I had a great germination rate and all growing well except 1 pot which germinated then just disappeared. I have up to 12 growing in 2" pots and I need to know, when do I split them up? I followed most of what Terry S advises in multiple posts and works well.

[Ali Baba]

I tend to let my pots of seedlings grow on as clumps and only split them once they are really short of room. I have had better results sowing in very early spring (around Feb/March) and then keeping the seedlings growing and watered through what should be their dormant period, it takes an effort to keep them cool and damp in the summer though. I use my normal mix, with finer grit than usual for sowing, and no extra heat, just greenhouse temperature.

[ChrisR]

You guys are making me want to grow some.
So if I grow from seed .... when is the best time to plant? At what temperature, heated propagation tray or cool GH? What Compost type? Gritty or organic?

All the info you need on Terry's website http://www.smale-conophytum.co.uk/