By popular request: germinating native cacti (updated summer 2022)

A few caveats

  • To my knowledge, none of the cacti around north-central Texas or central Oklahoma are legally endangered or threatened, but cacti can be highly desirable to plant collectors. So, PLEASE PLEASE PLEASE make sure any cactus seeds you have acquired are from a sustainable and legal source! The three species I have grown (below) are relatively common.
  • I am assuming in this blog post that you are growing within the native range of the cacti so that outdoor temperatures are not a concern once established.
  • I don’t really know what I’m doing. I have managed to get three of our local species (Escobaria missouriensis, E. vivipara, and Coryphantha sulcata to grow, but only the two Escobaria have as yet made it to a stage where I think they’ll live. The first C. sulcata died after sprouting, and the one I have now may or may not make it (update summer 2022: it perked up after the winter, but then a second new seedling died outside in the summer and the one later died, sometime after June 2022, but I don’t seem to have a blog post to link for it).
  • When I have encountered cactus genera in articles and resources, it appears the species in the genera Coryphantha, Escobaria, and Mammillaria seem to get reassigned among each other periodically, so I’m going to guess that similar conditions apply to all. I will specify the species given if it’s one of the three I have grown that are common in our region.

What to plant in

  • Soil needs to be well drained. You could go with cactus/succulent medium, possibly sterilized or with anti-fungal liquid added (pg 3 of Newland et al. 1981 suggests “Captan fungicide”). I did this for last year’s baby. What I did for the first time I tried was random dirt similar to where they normally live – I filled my outdoor planters with some sandy loam and gravel from a berm in my yard. The three-tiered planter had a lot of germination for E. vivipara (at least 7 up, though I didn’t count how many I planted), only a few (two? I don’t remember) for E. missouriensis, and one for C. sulcata. Not all survived, however – see “What to do once they sprout”.
  • Perhaps a pinch of local dirt from near the same species of adult cactus to ensure they get suitable mycorrhizal partners (Carillo-Garcia et al. 1999; Harding 2017). Most sources I read about did not talk about this aspect of germination, so I imagine many can make it without it, but germination or survival may not be as good. I didn’t do this, but if I try again in the future I will see if it’s possible.
  • They may need a bit of richer soil, as might be found under a nurse plant such as a tree or shrub or neighbor plant (Carillo-Garcia et al. 1999; Muro-Pérez et al. 2014). However, not too rich, as more northern Coryphantha (like ours presumably) prefer less organic matter. But not much. No details are given on how much is too much. Think about where you find the little round cacti around here normally – it’s usually up on barrens or dry hilltops, not a lush forest humus layer.
  • Make the seeds’ environment humid. Page 3 of Newland et al. 1981 provides a recommended cactus sprouting soil recipe and humidity-containing bag. As it’s for Arizona, I imagine it would work just as well for our cacti farther east here (ie if Arizona cacti can take the humidity recommended, ours probably need at least that). Edit summer 2022: we used plastic trays with clear lids to keep things humid for the 2022 Montana C. sulcata and got great germination rates (32+ out of around 50 seeds).

How to get them to sprout

  • Germination rates vary and fresher (ideally this season’s) seeds seem to be better. Love and Akins (“Second summary of the native seed germination studies of Norman C Deno: species with names beginning with letters C through E“, 2019, Native Plant Journal, vol. 20, issue 1, pp 65-97; not freely available online, so you’ll need to get it via interlibrary loan from your local library if you want it), actually have results for E. vivipara (22% germination in 1-4 weeks, at 70°F. with “a few more” seeds sprouting the following year) and E. missouriensis (65-80% in 1-6 weeks, specifically noted as being from freshly collected seeds, temperature not specified). For one Mammillaria species, less than a year old is best and two years was the maximum but germination was lower (Flores-Martínez et al. 2008). Another source said 2-3 years old at most, but I could only read the abstract as the rest of the article was in Russian. I would err on the side of planting sooner rather than later. My 2019-collected Coryphantha sulcata seeds (ie two years old) only had one germinate in 2021 and it took from Sept. 28 to mid December.
  • Surface sow. Most species, and this probably includes our local species (the three above at least) need light (pp 426-427, Barrios et al. 2020), so put them on the surface of the soil. Muro-Pérez et al. (2014) also argue against burying for a different species of Coryphantha.
  • Most cacti do well around 20-35 degrees C (aka room temperature or warmish), with an optimum of around 30 C (Figure 4, Barrios et al. 2020), including for temperate zone cacti (which is where we live).
  • I’m waiting to get this article via interlibrary loan and will update the post if it has anything new: R. BREGMAN, F. BOUMAN, Seed germination in Cactaceae, Botanical Journal of the Linnean Society, Volume 86, Issue 4, June 1983, Pages 357–374.

What to do once they sprout

Two steps forward, two steps back??

Saturday night (yesterday) planting more tomato and pepper seeds of varieties that haven’t sprouted well or I accidentally killed of sunscald (see end of post).
Yesterday, Mom and Dad sent me this cute little indoor fern friend and Paula added the little frog clip on top!
His Doggie outside yesterday, Gram had to curl tragically on her rope toy.
Couscous, venison roast, and shakshuka with the first indoor garden tomato (dwarf Audrey’s Love).
The cover radishes (Sparkler variety bought in bulk from Ellison’s feed store) have begun sprouting and the transplanted Viola bicolor aren’t dead yet. I just have to hope they will bloom and seed.
More of the radishes. The goal here is growing enough stuff to keep plants I don’t want out until I can get a ground cover started. (Friday)
The Mexican plum from home is alive! (Friday)
Thursday night, Wes wanted to look at things in yard with our new blacklight.
These (already hatched) eggs on the rock outside glow!
The porch loofahs are very welcoming.
Found more googly eyes just randomly in the raised beds.
While we were outside I examined the angry tomato seedlings.
I have determined that going from inside the house to the front porch every day is giving them sun scald, as the leaves are turning white but newer growth is a nice healthy green. So for now I’m putting them in the less intense backyard and that seems to be helping the survivors.
Same thing happening here, green new leaves with white, dying burnt leaves.

No vampires

Paula noticed more spider mites on the indoor peppers so we did garlic spray on them. I’ve also recently added a sprinkle more fertilizer to the pots since the leaves are yellowing. Hopefully this helps.
Then we decided to garlic spray the remaining tomato plant. Its fruit still seems to be growing but all the leaves on top are just drying up, even with more consistent watering. However, it’s growing new stems from the base. Not sure what the deal is.
In the backyard, Viola bicolor have flower buds.
A ground bee or wasp has a nice burrow near the potential greeneyes seedlings.

Garlic spray deployed!

Today I filtered the garlic spray twice so chunks won’t clog the sprayer.
Then I spritzed all over inside the mini greenhouse hoops area as well as directly on a few test chamomiles indoors. I think the neem oil may have made a few baby peppers and tomatoes wilt so hopefully this spray is less angering.

Garlic spray

I used the blender to pulverize garlic cloves that Paula got out for me (she was making focaccia anyways) and now I will leave it to soak overnight. This is another anti-earwig experiment.

Warm day garden activities

We’re watering and fertilizing two straw bales to become potato growing sites.  The one that we’ve watered and covered with plastic to keep warm is growing straw. At least it’s not got herbicides on it!!
We trimmed the Salvia greggii back for bushiness and spring flowering. We also did the winter pruning for both new and old fruit trees but I forgot to take before and after pictures.
Several seeds are sprouting in the hoops.  If you can zoom in, you may see the two oil traps for earwigs.  It is leftover fryer oil so it should excite their senses. We also planted two varieties of lettuce seeds we forgot before, and sprinkled leaves from the Salvia branches on the idea they might repulse earwigs. Finally, a few seeds are already up: purple lady bok choy, lacinato/dinosaur kale, Scotch blue curled kale, and French breakfast radish.
The daffodils I moved from along the metal edging to among the Salvias are coming up! Hopefully the trim will also make these more visible if they end up blooming. They were previously overcrowded and in the shade, so maybe out here they’ll actually bloom.

Tiny greenhouse

A little centipede in the garden dirt. Hopefully it’s an earwig predator.
Hoops in!
Seeds planted, cover on! We put lots of extra and smelly plants like cilantro and parsley among the carrots and bok choy and beets in hopes of earwig distraction.

Dwarf tomatoes update

The dwarf Audrey’s Love tomato is doing great.  Half a dozen green fruits growing, very few spider mites, new shoots at the base.  The dwarf Bendigo Dawn tomato was shriveling up, barely flowering (even after adding bone meal to both varieties), and infested with spider mites.  We decided to remove the one doing poorly; we trimmed and caged the happy one so it has more support.  We also spritzed it thoroughly with neem oil for the mites.

Earwigs indoors 😤

We mixed up neem oil concentrate with water according to the directions (~0.4 g oil per 2 oz water ie the size of our little glass spritzer bottles), and spritzed all the baby plants. We’ve seen three earwigs inside near the plants since repotting last night and several tomatillos, peppers, and chamomile look a bit worse for the wear.