09 February 2018

Haworthias: How to Sow Seeds et cetera

Time to update! If you saw this post, you're probably expecting that all this trouble poking at haworthias could not possibly have ended there. Those seeds did go in. The experiment was not trouble-free though; hence this follow-up post.  

Sowing the Seeds

As usual, when sowing seeds, sterilize everything. I recommend a shallow container (3 cm deep, say) with a lot of holes for drainage. There's a lot of fancyass kits and overly complicated methods for sowing any kind of seeds but in my experience the simplest way is best. In this case, mix potting soil with pumice, about half and half is good. Haworthia seedlings will need a lot of water and sowing them in gritty substrate (like I did, we'll talk about that idiocy later) will later require you to water them three times a day because, you know, you have nothing better to do. 

So! Shallow container, substrate as described, everything sterilized. The seeds should be placed on top of the moist medium and leave them there uncovered. Then, put the whole thing inside a ziploc bag. This thing has to remain most until they have germinated. Notice that their seed coat form a hard shell around the endosperm. If they dry out, the sprout is not going to be able to push it open. The moisture will have to soften up that shell. This is also the reason why you can't skip the sterilization process--they don't have to be sterile forever, just long enough to avoid damping off in the two to three weeks it will take for germination to occur.

Once the seeds have germinated, open the ziploc bag but do not remove it. The idea is for a bit of air to get in but not so much that it dries out the medium. You will need to spray the seedlings, preferably with distilled water just to minimize fungus or whatnot. 

And, I can not stress this enough: LABEL YOUR POTS! You will thank yourself later. 
This is what month-old haworthia seedlings look like. They will likely stay like this for a while.
The first true leaf appear in about a month and will stay singular while the seedling develops its first root. While it is trying to get purchase, they need to be kept consistently moist but not wet.
I sowed my seeds in fine akadama which is that brown clay-ey stuff in the photo above. You'd think it would have been perfect for keeping haworthia seedlings moist but not wet. Well, sure. If you are willing to water it three times a day. These seedlings need a lot of water. I mentioned the akadama experiment to make you think twice if the same idea popped into your head. To make the akadama idea work, I probably would have needed akadama dust, not just akadama fines. Haworthia seedlings have roots that are so small and grow so damn slow that if your medium is too coarse and airy, the root sprout will spend too much time not touching anything moist. They dry out and the seedling has to start again.

In the end, I decided to replant all my seedlings in a mix with actual soil in it. This was how I discovered none of them had grown long enough roots to get a purchase of the akadama. Most of them were just sitting on the surface, starving. Transplanting anything this young is a bit harrowing so try to avoid it.

If you do need to transplant, a pair of gentle tweezers will help a lot. Don't bother actually planting them. Just point them down into the soil. Once transplanted, you'll only need to spray them every couple of days until you see them plump up a little. After that, reduce your spraying frequency--maybe every five days or so. 

When the seedlings start growing new leaves, you can actually let them dry out in between watering. By that time, you can shift from gentle spraying to bottom watering. No need to soak all to shit, just heft the pot and if it feels a little heavier than before, that's enough. Roots will try to grow downwards where the moisture is. 

Three months later, the plantlings have started growing their third and fourth leaves.
Next in this series: When to individually repot haworthia seedlings. Right now, I don't know, we'll see. I want them a little bigger. Also, it's nearly spring and if you hit this same time of the year when they are this size, we're all probably better off leaving them undisturbed to take advantage of the growing season.

But, just to satisfy our curiosity, this is what haworthia yearlings look like at this point:
I planted this seedling in its own pot and just so you know, I'm regretting it already. It needs daily spritzing.
Without its daily spritz, a plantling this small in this medium, will die.

We'll see next autumn.

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