Planting cacti seeds

[Rich66]

Hi
I’ve never grown by seed before and it’s my first time. Can anyone offer me advice please on the best way to go about it as I’ve never done it before.
Many Thanks
Rich

[Davey246]

Everyone will have their own recipe.

The one thing that I cannot recommend highly enough is to sterilise everything (apart from the seeds) before sowing.
I do this by microwaving everything used for sowing, and running boiling water through plastic pots. Composts/sand/gravel etc. needs to be damp and is simplest to microwave if it is in a LOOSELY tied roasting bag - microwave until the bag puffs up with steam and then leave to cool.

I haven't looked to buy any for ages, but water the seeds after sowing with a fungicide. I bought plenty ages ago but use a copper-based fungicide (a modern version of Bordeaux Mixture), which may no longer be available??????

I have always used the pot in bag method - usually a 2.5 inch pot for up to 30 or so seeds, but depending on species, in a small sandwich bag, wire-tied shut. If you judge the watering correctly, the bag need not be opened again for at least a year and the compost will certainly not dry-out anything like quickly or suddenly.

All seed should be surface-sown - I use a thin layer of fine grit over them but not enough to actually cover them - just 2-3 grains deep, or sow fine seed (Aztekium, Blossfeldia etc.) into fine grit, many do not.

[habanerocat]

The seed raising leaflet is here:

https://www.society.bcss.org.uk/images/ ... atemix.pdf

Pages are a bit mixed up but it's a good place to start.

I keep these two threads bookmarked. Plenty of more info if you do a search.

viewtopic.php?t=166614&hilit=propagator

viewtopic.php?t=171130

[NickHitchcock]

May be useful.

https://seedscactus.com/en/content/26-sowing

[Chris L]

https://www.manchester.bcss.org.uk/imag ... -guide.pdf

I have been quite successful with 50% John Innes and 50% Molar Clay/Cat Litter/Oil Spill Granuals (by volume).

Tesco blue tie handle bags work well for me - I always KNOT the bag tight NOT a tie wrap - the bag must be air-tight to work the best. https://www.tesco.com/groceries/en-GB/p ... /288423796

East facing windowsill is better than in a GH or conservatory.

For best results plant as many pots as you've got room for.

[Davey246]

the bag must be air-tight to work the best. https://www.tesco.com/groceries/en-GB/p ... /288423796

Polythene "breathes" oxygen, nitrogen and water at a remarkable rate - air-tight is a common fallacy/misconception.

No crisps or biscuits are packaged in polythene bags, if they were, they'd be soft within a few days. Even the orientated polypropylene that is used has to be coated to slow gas/water migration and most crisp packets also have an aluminium layer too, for the same purpose, not decoration.

The bags that I use are 8 x 6 inches - more than ample for anything up to a 10-12cm half-pot, and it would be impossible to knot one with even a 5cm pot inside.

Tie-wraps are certainly to be avoided although you can buy ones that will release. Far, far, far cheaper, easier and simpler to use wire ties, which sandwich bags always used to be sold with.

[MatDz]

The grip seal 5" x 7.5" polythene bags I am using are definitely humid enough half a year after sealing, then some might need a little extra spray of water and are good to go for another half a year, are super simple to seal and can be reused many times. Size is also perfect for 5 cm/2" square pots.

[Davey246]

When I was propagating on a grand scale, my propagaotor of around 30 x 24 inches was FULL of 7cm pots, all of the time, so packing them was simple with bags tied into what amounts to a spike or spire. Sandwich bags are also about as cheap as they come, although I did buy some that were crazy, too, thin.
If bags don't spend too much, or no, time in sunshine, including in a greenhouse, they can be used and reused time after time, after time.

[Tina]

I use zip top bags, much easier, I have left seedlings in these for years with the odd spray if necessary. Especially for the really small slowing plants like strombo, aztekium, blossfeldia etc.

[esp]

There are a number of variations about the basic method- warm, fairly bright but not full sun, and sterile medium.

I use small plastic containers with lids to sow seeds rather than baggies, but the principle is the same.

The only thing I'd add is to take it slowly and experiment - maybe try a few seeds as a trial and let them grow for 3-6 weeks to see if they progress well and you have any modifications you need to make to your methods before sowing loads.