I have 10 San Pedro cactus seeds and I've never started cactus seeds before. Can I start them now, keep them inside and under artificial lights over the winter (I'm in southern BC) and then move them outside when it warms up again? I hear that a mix of half sand and half normal potting soil works well, is that a good medium to start these with? How fast can I expect these cactuses to grow? Does anyone have much experience with San Pedro? These seeds sure are tiny --- I hope someone didn't make a mistake and gave me sand grains by mistake. :)
I think you should check with the Canada Food Inspection Agency to see if growing San Pedro is legal in Canada
Yes it is. I checked already. It's only illegal if you process it and extract/purify the alkaloids. Not that there's much to be concerned about anyway --- cultivating papaver somniferum IS illegal in Canada but almost every block has a house with a garden that has tons of them and I've never heard of anyone getting in trouble. I don't think Canadian law enforcement has deteriorated to the point where people growing one or two cactuses for ornamental purposes have cause to worry about the law. Good point though.
I just started a bunch of cactus seeds. Yes, they are tiny. The sand/cactus mix is a good idea. Cover the seeds just barely with a VERY light covering of soil (or just sand) - put the pot in a sealed plastic bag for high humidity, and keep under bright light and at about 20-30C, just above room temp. if you can. Spray mist on them to water rather than using the watering can, because they are so delicate when small. They will probably not grow fast for the first few months, but as they get bigger will respond more to fertilizer etc. and do a few inches a year, maybe more.
That technique sounds like what I've been reading --- keep the humidity high by sealing the pot in a plastic bag and then gradually open the bag with larger and larger holes as they grow. Others have said that sterilizing the sand and soil first in an oven is a good idea. I don't know if I'll bother with that. They say the advantage of San Pedro is it's relatively fast growth rate and the fact it's supposed to be able to tolerate a wetter medium than other cactuses. My climate can be wet. I'm in between the ocean and the coast mountain range here so it can be cold and drizzly for months.
A faster way to sterilize the soil, is in the microwave, the reason for doing it, is because of the high humidity that you are creating with the bag. The seeds being small as you say could be overwhelmed quickly by a fungus. For the amount of time that it takes to sterilize, its worth the hassle.
Carol, what's the quick-n-easy microwave way to sterilize soil? It'll be a mix of sand and potting soil for cactuses. How long do you have to nuke it for? Does it make a horrendous smell?
I make sure that the soil is moist and then nuke it until it is very hot and steamy. I can't tell you how long. I nuke it until it is nice and hot and then let is sit in the closed container until it cools down. No, the smell isn't that bad. It smells like hot, wet soil, but it's not stinky and fowl if that's what you were wondering.
".... until it is very hot and steamy." OK, fair enough --- I guess as long as it's brought to boiling temperature it's as sterile as it's going to get. And it doesn't smell bad --- good deal. Thanks globalist.
Hi Carol Sorry, was too busy to respond til just now. OK, I nuked my cactus growth medium for 10 minutes and started my seeds (god, they're small!). I have the pot covered with a plastic bag and a sunlamp on it to keep it warm. I'll keep you posted as to how it goes. My brug bloom is over 5 cm now, I sure hope it blossoms fully soon and I can see what the scent is like that everyone talks about so much. Thanks for the advice, Carol. Now that the soil is terilized, hopefully mold and fungus will be less of an issue. Regards, Tom
Those seeds all failed to sprout, except one which died shortly after sprouting. However, I kept at it and now, a few years later I figured out what the problem was: the seeds. I used essentially the same technique with fresher seeds, and they all sprouted. I have several hundred little, cm-high, emerald green cactuses now, under a 100 watt CFL, fattening up for summer. :)