BCSS - Forum

I am wondering what is the most time efficient way to get cactus seedlings to flower?

I am looking at raising some hybrid Echinopsis with a few to trying some of my own crosses combining a few different lines. From reading around, the standard approach seems to be to sow them about now then give them fairly standard cool/cold winters commencing watering again around March and then stopping again around September. This should give some flowering in 4-5 years.

To my mind it seems we are then looking at only getting around 6 months growing time per year. For those flowering in 4 years that seems to only give around 20 months growing from seed to flowering.

Is there any reason why we can't extend this growing season and get them flowering in less years? Obviously they will need a cool winter before flowering but apart from that do they need a cool winter if they are not flowering size?

Could the following regime work to reduce flowering time down to their third summer?

1. Seeds sown October/November (As soon as seed is clean and mature really) and kept under lights with daytime heat to keep them growing.

2. Seedlings / plants grown as normal through the summer.

3. In Autumn, plants moved to a warm conservatory with very good light levels (and possibly supplementary lighting) to keep them growing through winter two.

4. Plants given normal summer.

5. Watering ceased in September and plants given cold, dry winter rest in greenhouse.

6. Plants (hopefully) flower early the next summer after watering commences.

They would then effectively grow from October/November for around 23 months non-stop before ceasing watering in the September of their second year.

I'm hoping this would reduce my generational time and allow more crosses in the same period of time. Do you think it will work? What will be the issues?

It is time for you to experiment!

Certainly the big Dutch wholesalers get their plants to flowering size much more quickly than the average amateur. They use higher winter temperatures and I guess auxiliary lighting too. Also growers in places such as Texas only have very short periods of dormancy with their cacti. Our Forum friend in Taiwan seems to get his plants to a good size quickly under his subtropical conditions.

Don't forget that you can also seedling grafting to speed up growth.

I get good growth if I have the space to keep seedlings in the propagator for 2 winters e.g. typically sown January, removed from propagator around 15 months later). They don't need a cool winter if you aren't looking for flowers.
I'd think you'd need supplemental light as well as warmth to make the best of the second winter, otherwise you will get minimal or etiolated growth.

I water my seedlings all the way through their first winter (sowing them in early march, pricking them out as soon as they are "big enough" - a bit bigger than the head of a matchstick).

They only grow a little in winter, but do get off to a good start for the following spring. Echinopsis hybrids probably wont flower in their second year like this (Aylosteras often do), but at least some should flower their third year.

This is without any extra heat and light (except when as seedlings in the propagator, which is heated to 20C, for first 6 months or so). I do have good light where I am, but the plants are unheated throughout the winter.

Here's a picture of some crosses which are about 22 months old. They are about 3cm across now:

Thanks Terry, Ralph and Esp.

I am already experimenting a bit this winter with some small Echinopsis plants in the warm conservatory (my office at work) to see how they do. The light in there is very good - I've got an Aeonium 'Zwartkop' in there at the moment that is blacker than I can get them outside on my deck in summer. However O could always add an LED strip to extend the day length. It's heated to around 20oC in the day falling to 10-15oC, at worst, overnight. As it'll be heated whether there are plants in there or not it seems a pity not to take advantage!!!

I've bought some hybrid Echinopsis seeds this year to further experiment with. They are currently germinating nicely to see if I can get some into flower in 2022! If there are any nice flowers I can use them for further breeding or, if not, compost them or give them away if they are wanted by someone. Hopefully I'll have a few crosses myself from this summer if the plants I want flower at the same time to try next year.

I did ponder grafting too but people seem to use robust Echinopsis as a rootstock so I wasn't sure that it would add too much of a boost? If the plants aren't good growers I don't want them in the breeding program.

They look very promising Ralph. I reckon at worst then I should be looking at my aim of flowering in the third year and, if they get a brief cold spell, possibly earlier. As I get some experience of what size they need to be to flower, I might be able to give them a brief cold spell towards the end of winter to try and trigger flowering in their second summer which will trim another year off and really speed up the time between generations.

If anyone else has tried any other regimes to boost growth I'd love to hear about it.

The other thing I meant to ask about was pricking out / repotting.

This is what they currently look like, around a month after sowing.
I've definitely sown them too thickly / unevenly to leave them in these pots for too long.

But, with looking for the most rapid growth, am I best to just drop these on into a larger pot? ( I was thinking of dropping these 4cm potfulls into a 6cm pot and then possibly into an 8cm or larger.

Or would I be best to prick these out into a community pot / tray to space them out better? Or would they be better one to a pot then?

Or is a combination of the two best? I.e. drop them on into a 6cm pot so there is no check in growth then, when they are large enough, prick them out into a seed tray / half tray.

And when should I prick them out / pot them on? What am I looking for with cacti to tell me they're ready? (With 'normal' plants I'd be doing it after the first true leaf is developed!)

Thanks in advance.

I would leave them for about a 12-15 months, myself. By then they may look like this - though these haven't had the luxury of a 2" pot, only a cell just under 4cm across.

edds wrote: ↑Sun Jan 12, 2020 4:06 pm The other thing I meant to ask about was pricking out / repotting.

This is what they currently look like, around a month after sowing.

I wouldn't dream of pricking these out at this age.

If you think they are too close together, it's a trade-off. Do you pull them out and seriously risk damaging all their roots, killing them off? Or do you leave them, and let the stronger seedlings win against their weaker brethren resulting in the odd loss?

For me it's clear, I leave them as long as poss. It is surprising how seedlings seem to survive and thrive. In situations like this they are remarkably resilient.

Phil_SK wrote: ↑Sun Jan 12, 2020 4:49 pm I would leave them for about a 12-15 months, myself. By then they may look like this - though these haven't had the luxury of a 2" pot, only a cell just under 4cm across.

It would help if I had included the picture, wouldn't it?

ragamala wrote: ↑Sun Jan 12, 2020 5:17 pm I wouldn't dream of pricking these out at this age.

If you think they are too close together, it's a trade-off. Do you pull them out and seriously risk damaging all their roots, killing them off? Or do you leave them, and let the stronger seedlings win against their weaker brethren resulting in the odd loss?

For me it's clear, I leave them as long as poss. It is surprising how seedlings seem to survive and thrive. In situations like this they are remarkably resilient.

I wasn't planning to either prick out or pot on for a couple of months at the earliest - maybe some time in March. I am talking about the timing - will March be too early?

I know people often leave cacti for longer, as in Phil's example, but I can't help but feel, in a quest to maximise growth, they would have grown faster if potted up to the next size pot or pricked out before then.

Maybe potting the seedling pot into a larger pot might be the best of both worlds - more room for the roots and possibly seedlings to expand (those on the edges at least!) but minimal root disturbance to stop a check in growth that will happen when pricked out?