First seed-starting attempt

[cedillamuerta]

Hello hello! This is Cedillamuerta. I checked on my seed order today and I should have them by early next week! I didn't expect it would be so fast so I need to get on the ball! I will hopefully be posting pictures and updates of how my seeds are doing, but first I have a bunch of questions. I will be modeling my approach loosely after >this one<, mostly in the fact that I want to use 100% inorganic matter. I'll be using OIL-DRI, which is a large grained clay product much like NAPA 8822. First of all, is just clay granules sufficient? I'd like to keep the mix as simple as possible and it's not easy to obtain a lot of these products here. Secondly, when I sterilize the mix in the microwave or oven, is there any danger of it popping or exploding in some way? And will it smell if done in the oven (because it's completely inorganic)? Also, since I don't have artificial lighting or the room for it, I'm going to be starting them in natural sunlight. How do I prevent the seedlings from cooking in the sun? Next, I'd like to ask if any of these seeds don't last long, need time to germinate, or if they need really special germination conditions.

Bolivicereus samaipatanus
Cleistocactus mix
Echinocereus mix
Espostoa mix
Eulychnia breviflora
Facheiroa squamosa
Facheiroa ulei
Ferocactus gatesii
Ferocactus cylindraceus
Neoporteria mix
Pachycereus pringlei
Rebutia mix
Saguaro

All in all, I ordered about 500 seeds. I'm starting with a bang! Please feel free to advise, critique, whatever.

[apfire]

Wow!! way to start big. Growing from seed is habit forming. Good luck!!

[greenknight]

You don't want them in direct sun in the early stages; either put them in a position the sun doesn't hit directly, or provide shading. Tissue paper works.

[CactusFanDan]

Direct sun will fry them quickly. Bright shade is advisable, but the light still might be too strong for some. While excluding organic matter from your starting mix is good for developing strong roots, it's also more time consuming since you have to fertilise your seedlings regularly and religiously. By using an open mix with some organic material (like I do) you can still get your plants to grow strongly and quickly, but you also don't have to pay as much attention to them. The 'baggie method' is also very useful in this respect.

In my experience, you can microwave/cook pretty much any soil components without anything blowing up. Even time-release fertiliser pellets microwave fine. You sometimes get a bit of a scent coming off, but unless you've got it hot enough for stuff to start decomposing (very very hot) then the smell would only be the same that the soil mix usually has, although perhaps a little stronger. All those seeds should germinate just fine given the right conditions, which aren't any different from the usual germination conditions.

[cedillamuerta]

Alright! That sounds great. I'll use a small amount of coconut coir for the organic matter component. Any suggestions for a good percentage? Also, what exactly is bright shade? Parts of our back porch are shaded all day and surrounded with varying amounts of sun. Is that what that means? Shade with nearby bright sun?

[CactusFanDan]

Coir doesn't really have a very high nutrient content. I use top soil myself, but maybe others can tell you if coir is good or not. Bright shade. I suppose it's not easy to classify. You don't want to give your plants any direct sunlight, so I suppose an outdoors spot which doesn't get any direct sunlight would be ideal.

[greenknight]

Coir is similar to peat, no nutrients. I use a potting mix that contains worm castings, but topsoil is also ok - if you get it hot enough to kill any weed seeds. Worm castings contain no weed seeds - the worms would digest them.

[cedillamuerta]

Got my seeds in yesterday Starting them looks like it's going to be a lot more labor-intensive than I thought (as if I ever think ). Anywho, I've started up 3 baggies so far and have been keeping them on my warm back porch in a shady area. There are lots of ferns growing there and some moss I left on the concrete there has never dried out so I'm thinking it's a nice spot. I put them in a 10-1 mix of OIL-DRI and this really airy peat/perlite mix they use at work. I baked it in the oven at 200° and sterilized the pots with hydrogen peroxide, so I don't think rot will be a problem. Now it's just a matter of moisture and light.
The mix was a little moist as it went into the oven and didn't change much after. I spritzed it a little with a spray bottle, but how moist does it need to be? Also, which seeds will be the fastest growers? My friend would like to have a cactus to have in his apartment hopefully by the end of the year. Will post pictures sometime soon!

[greenknight]

The usual recommendation is to soak the pots/trays thoroughly at planting, allow them to drain, then put them in the bags. They can be quite wet to start with, but not saturated. As long as the medium is moist, should be OK.

[CactusFanDan]

Sounds good! I tend to add enough water to each bag so that there's a little standing water in the bottom of the bag, which the pot's sitting in. This ensures the whole soil mass is at least slightly moist, since water will constantly be wicking up from the bottom and evaporating at the top of the pot. The water cycles like this in the bag, which helps to maintain humidity as well. As for which are fast growing... I'd say they should all be relatively fast growing, but in particular the Pachycereus, Espostoa, Eulychnia and Cleistocactus should be fastest. Maybe the Ferocactus too.

[cedillamuerta]

Hooray! As you can probably already tell, I love columnar cacti. I know I'm going to have to be patient with this, but how many days does it take on average for the seeds to sprout?

[cefalophone]

It can take anywhere from 5 days to 2 months in my experience. It depends on the freshness of the seeds

[CactusFanDan]

Fastest cactus seed i've had to germinate was about 2 or 3 days. The longest? Ongoing. However I had one germinate 5 months after sowing last week.

[cedillamuerta]

Got my first germination yesterday! Saguaros came out to play first, surprisingly. Then, Ferocactus gatesii was germinating when I checked this morning. Now, I've got these seedlings in a spot that's shady all day long, but they're only a couple of inches away from a spot which gets several hours of bright sunlight. Upon close examination, the Saguaro seedlings are mostly yellowish, with just a little bit of green around the edges. There is also a tiny bit of faint orange in the center of the seed leaves. I would assume that they just haven't "filled in" with chlorophyll yet, but is it an indicator? Would they be showing signs of too much/little sun exposure already or am I just overthinking things?

[greenknight]

Give them a few days.