Most difficult cactus to flower

[gerald]

For growing cactus this spring the weather here in Oxon has been pretty much perfect, as such nearly every cactus that I thought would flower has done so.

Some remain stubborn, as we know they can be, but there is the rest of summer to go yet so there is still time. I was wondering which cacti people find the most tricky to bloom, apart from those Cerei etc which need to grow to large old specimens first.

For instance, I've had two Mammillaria tlalocii for years now, can I get a flower out of either of them? No! Same also for M. geminispina var. nobilis - all other Mamms no problem - but not these!

[juster]

This is interesting Gerald, I had M. geminispina for years and grew quite a clump before it departed - I don't recall that it ever flowered. At present I have a Copiapoa krainziana, grown from a single head and now in a 12" bowl, looks good but it has never flowered.

[jfabiao]

I've had one large (for the species) plant of M. tlalocii that took more than 20 years to start blooming (probably due to my inability), but now does so regularly and profusely. However I have two other plants of the FO229 population that started to flower at about thumb size, so it must be that some populations are Mammillaria-easy and others are stubborn.
M. geminispina is not reluctant at all for me, but it never flowers profusely. That coupled with the small size of the flowers may account for them passing unnoticed.
I must admit that under the portuguese sun and warmth cacti will bloom a lot easier than in the UK, but one species I have that fits the "big enough to but won't" bill is Leuchtenbergia principis.

[Eric Williams]

Strange that Jfabiao, my plant in the UK flowers very well, and every year too. Seems it loves water. Cheers

[FaeLLe]

Never had my Yavia Cryptocarpa flower; not sure what it would take.... the whole plant looks dead all year round except for rising immediately when it is watered after a long spell of drying out.

[Eric Williams]

Hi FaeLLe, my Yavia flowered every year until a few years ago when it went cristate for what ever reason. Never had a flower since, I wonder why. Cheers

[jfabiao]

Strange that Jfabiao, my plant in the UK flowers very well, and every year too. Seems it loves water. Cheers

Thank you, Eric. I have read in numerous occasions that preference of Leuchtenbergia for water, and I oblige by watering it deeply every time. It responds well, with good growth, but alas no flowers. I may try to repot it to a larger container and see if the extended wet soil period will make a difference.

[gerald]

Strange that Jfabiao, my plant in the UK flowers very well, and every year too. Seems it loves water. Cheers

Thank you, Eric. I have read in numerous occasions that preference of Leuchtenbergia for water, and I oblige by watering it deeply every time. It responds well, with good growth, but alas no flowers. I may try to repot it to a larger container and see if the extended wet soil period will make a difference.

You could also try a high potash fertiliser in the spring

[daniel82]

My Sulcorebutia breviflora completely refuses to flower It's came from hollygate years ago, is in great health and grows really well. All my other sulco's flower including a breviflora L314 which is next to it and is blooming today!

I guess everyone has a plant which is difficult to flower for them.

[DaveW]

Plants are like humans, provided they are not clones, each one is an individual. Some humans are precocious and others are not. The same with plants, some will flower much earlier than is normal and some much later, that is just the natural variation evolution works on. Add to that the microclimate you are growing them in and yet another variable enters the reckoning.

I was given three Denmoza's by a friend about 2 inches diameter from collected seed. I expected they would need to be quite large before flowering, but one has now flowered for the last three years, but no sign of the others doing so that were from the same batch of seed and probably the same seedpod he collected.

My reasonably large Mammillaria gemnispina flowers every year, but intermittently with only one or two flowers open at a time. You never get a complete ring of flowers around the head as with most Mammillaria's. I too have only flowered my quite sizable Leuchtenbergia once in all the years I have had it, yet a friend flowers a smaller one regularly.

If you have more than one greenhouse, sometimes merely moving a plant from one greenhouse to another will promote flowering due to the different microclimate. Also where you live can make a difference. A friend of mine who used to live about 4 miles away from me at a lower elevation claimed when he moved up here plants flowered he had never flowered easily before, but others sulked. Now was that change of location, or merely change of the greenhouse microclimate, or something else?

I have sometimes had a plant of a species that flowered small but lost it in a bad winter due to an unheated greenhouse, but then never found a replacement that would flower as small or as floriferously.

Another variable is winter temperature, some plants flower better if the greenhouse goes down to, or below freezing in winter, some flower better if a high winter temperature is maintained, it all depends on the individual plant and the species we grow. It is human nature we all want to grow the rarer plants that do not thrive in our conditions, but dismiss the ones we grow easily which others have trouble growing. With the considerable range of habitat conditions cacti grow in it would be remarkable if the conditions in one greenhouse suited them all.

I knew a chap many years ago who grew insectivorous plants. He asked at Kew when he went there if they had a certain species and was told "yes we have it in micro propagation since it is extremely difficult". He told me he had a laugh to himself since it came up as a "pot weed" all around his greenhouse and was one of the easiest to grow he had. Different conditions and methods of cultivation, plus different cultivators suit different plants.

My Sulcorebutia's flower freely and all go down to freezing in winter, but the one that refuses to flower for me is Sulcorebutia rauschii which I have only flowered once in many years,