So I volunteered to be a plant foster parent over the winter. One of my coworkers (after seeing pictures I shared online of some great Haworthia maughanii) ordered some seeds online and was asking about starting them; after I started describing the steps I use, we realized that without a setup with lights for winter, the best option was a windowsill (Which would likely be a bit too chilly and drafty with shortened winter daylight hours) – and I volunteered to try starting a tray of half the seeds over the winter to get a jump start on these very slow growers. She didn’t have to twist my arm too hard. I’m far from an expert, but I still had some seed mix left over from the seeds I started in July, two pans, and one spot in my seed starting tray that would fit a pan.
While I’m not an expert, I do a lot of reading – and have had some advice from folks who’ve supplied with some seeds to try while I’m waiting for a chance to try breeding my own hybrids – so here’s my approach.
First, though – let me start with a disclaimer to proceed with caution if you are purchasing “rare or exotic plant seeds” of any variety online. Recommended reading on this (if you are planning to order seeds online) at the end.
If you know the harvest dates of your seeds – this is especially useful information. Haworthia seeds in particular (I’m told from growers that are big names – thanks Renny!) have the best germination rates when they have had at least 2-3 months of time to dry out and rest – preferably in a paper envelope, not a plastic baggie. After exercising patience that long — then you can sow.
I use a disposable aluminum “mini loaf pan” from the supermarket. They are amazingly cheap, versatile, disposable — and I can put them in the oven. I typically will grab a small nail and poke several holes through the bottom for drainage, then load them up with my soil mix (more on that below).
As for a soil mix – this is tricky. Haworthias like a gritty, well draining soil – but the seedlings to be kept humid and moist for germination and for the first few weeks/months of life. The mix I use is borrowed from zen haworthia master Gerhard Marx as described on web page (http://www.gerhardmarx.com/p/succulent-cultivation.html).
The mix is as follows:
- 1 part perlite
- 1 part vermiculite
- 1 part compost (or in my case, succulent-formula potting soil)
- 1 part river sand (quartzite sand recommended by GH – not salinated beach sand.
On top of this I sprinkle a very thin layer of my “fines” – aka, the stuff that sifts out when I sift the gravel/turface/pine bark for my adult plants. It’s just to level out the surface a bit and to help give the infant seedlings something to latch onto and dig into – otherwise they have a tendency to potentially lay on the surface of a rocky patch for a bit.
I will fill about 1/2 – 3/4 of an inch in my mini loaf pan – set that on a large piece of tinfoil, and bake it at 180 degrees for 30 minutes. I’ll take it out and let it cool for a bit – then rinse it to wet it thoroughly from above. This time I will wrap the large piece of foil around it to seal in the steam, and bake it at 180 degrees for another thirty minutes. When finished, I’ll take it out and let it cool overnight without unwrapping it. I’ve sterilized it, I want to keep it sealed as much as possible from this point on.
When ready to sow, I take a small plastic cup and put in a small amount of bleach, and dilute it with tap water. The seeds are going to get a quick bath in the diluted bleach mixture. I don’t exactly measure, but it’s about 10-20% bleach to water. Most of the mold and other contaminants that will enter any seedling tray come from the husks and shells of the seeds themselves, so sterilizing the seeds in some manner like this is important.
From there, I’ll take a wooden toothpick, give it a good stir, and use the toothpick to fish the seeds out. The seeds have a bit of a sticky coating on them when wet, so they usually stick to the toothpick (if you can separate them from each other). From there, it’s fairly easy to dab them onto the surface of the soil and sort of “roll” the toothpick between your fingers to get them to let go of the toothpick and grab onto the soil mixture in the tray.
As soon as they’re all placed, I spray the surface with a diluted garden fungicide spray – place the lid on to seal the tray, and place it under my fluorescent lights on a shelf on top of a thermostat regulated heat mat (The same one I use in spring for starting annuals and vegetable seedlings). This setup is in my basement, which stays a bit cool even in summer; I’ll set the thermostat to about 80-82 degrees for a few hours in the later part of the day before turning it off for the evening, at which point it generally falls to high 60s or low 70s with the ambient temperature of the house.
It generally takes about three weeks for germination (in my experience) — sometimes seeds will pop up much later than that, so don’t give up, or despair if only a few show up at the three week mark. If you get nothing, you can always let the tray dry/air out, wait a few weeks, and try again later by rewetting/resealing the soil tray and trying again.
Once you have germination, start opening up the tray to get fresh air; first for about an hour at a time, gradually increasing the period it’s exposed so the seedlings get used to drying out a bit. Mist morning and night for the first weeks, then switch over to just 1x a day. After a few months, I’ll start moving to a more thorough drench and dry cycle typical of an adult plant. For mosting, I either use a diluted fungicide or a diluted mixture of water and hydrogen peroxide (generally about 3 tablespoons for a full sized spray bottle).
The most important part is sterilization. Once you start opening the tray for fresh air, it’s inevitable (it seems to me) that you’re going to start getting some moss or algae on the surface. Some folks recommend sprinkling cinnamon (which I’ve tried) as the oils help kill the algae, but I’m always afraid of what that might do to tender seedlings, so a lot of the time it’s cross my fingers and hope for the best so far. Anything you can do to delay the onset of that until the plants get more developed is in your best interest.
Some folks – especially with cactus seedlings – will recommend keeping the tray sealed for the first 3 months or longer; but that also exposes you to the risk of rotting the seedlings, so I choose to take my chances with algae in the hopes that letting the top layer dry out a bit will help combat that.
A note about online ordering of seeds:
Right now there are a lot of unscrupulous sellers who are going to sellyou counterfeit seeds safe in the knowledge that you’ll be long down the road before you have time to loop back and ask for a refund or leave a poor review. You’re going to end up with some strange plant – or a weed – more likely than not. I know this from experience! Fortunately for my coworker, the seller she found on eBay is (I’m fairly certain) reputable. My advice:
- Look for details. Specifics are good. Information about the harvest date, images of both parent plants, Etc.
- If the plant in the picture looks especially crazy – google image search to compare. Counterfeit sellers will use a lot of fake pictures or photoshopped ones to sell especially bizarre looking “plant” seeds to casual folks.
- See if the seller only sells seeds, or if they have live plants too. Your odds of it being authentic go up dramatically if there’s evidence they actually have the plants that they’re selling seeds from.
- Avoid international orders if possible – especially from China. One, counterfeiting seems to be more prevalent in international orders; two, you run the risk of getting your order tangled up in customs. Most things are fine, but there is a list of plants (CITES) registered as endangered that require special permits to import; even things not on that list require special certificates (phytosanitary) for legal import, which requires a customs inspection… which frequently can take several rounds of inspection to pass.
- Also– reputable well known buyers are good. The “poaching” of wild plants – even their seed pods — is a problem for some species of exotic plants, specifically of cacti.
Domestically – there are a lot of seeds available from CactusStore or my favorite – MesaGardens. I’ve had good experience with both. Just be aware that patience is required – a lot of these places are popular sellers, but are still more of personal operations that are labors of love for those involved, and it can sometimes take a few months for your order to get processed depending on the time of year.