My four Welwitschia mirabilis seedlings are about to spend their first winter in the greenhouse. Two are from seed I sowed in 2024 and are now a little over two years old. The other two are from July 2025 and are about 16 months old. They don’t look like much yet, just two strap-like leaves with the dried seed leaves at the base. I lost a lot of seedlings to get these four, so this post is mostly about that.
I sowed 20 seeds over two years, and 19 of them germinated. Four are alive today. Every one I lost died of damping off, somewhere between two weeks and three months after it came up. The ones that made it past three months have been fine ever since.
Where my Welwitschia seed came from
I sowed two packets of 10 seeds, both from Rare Palm Seeds: one in 2024 and one in July 2025. Germination was fine: 9 of the 2024 seeds came up, and all 10 from 2025 did. It took 2 to 7 days.
I usually put one seed in each pot, but a few pots got two. Two of my four survivors grew in those shared pots.
How I sowed Welwitschia seed
Welwitschia puts down a long taproot straight away, so I didn’t use the shallow bonsai-style trays I sow most things in. I used square pots 4 inches (10 cm) wide and 8 inches (20 cm) deep. All four seedlings are still in them.
The mix was 80% perlite and 20% coco coir with a small amount of slow-release fertilizer. It drains very fast, so in summer heat I was watering the seed pots every two to four days. What you see on the surface in the photos is a mineral top dressing, not the mix itself. My other mixes are in my soil mix post.
Before sowing I poured boiling water over the mix to sterilize it, and soaked the seeds and treated them with a copper fungicide.
The pots sat in a clear plastic box at 25°C (77°F) or a little warmer. As soon as I saw the first seedling, I lifted the lid slightly to let air in. Over the next 2–3 days I opened it a bit more each day until it was off completely.
Losing seedlings to damping off
Seedlings that had come up fine then started dying of damping off, the first after about two weeks and the last at around three months. In the end I lost 7 of the 9 from 2024 and 8 of the 10 from 2025.
I honestly can’t say whether the boiling water and copper fungicide did anything. With good seed, I don’t think they helped germination, because nearly all of it would have come up anyway. And they didn’t prevent damping off: I did both and still lost 15 seedlings. Maybe they help someone else, but for me they weren’t enough. Next time I’ll try other ways to cut these losses.
Welwitschia seedling care after the first three months
Welwitschia wants far more water than my other caudex plants. In summer I soak them twice a week. In the colder months I water less, but I never let the bottom of the pot dry out completely. During their balcony winters I watered only on sunny, dry days when the daytime temperature reached 10°C (50°F) or more.
The seedlings spent both winters on my closed, unheated balcony, sitting on heat mats because they were still so young. I wrote about those balcony winters in my post on minimum winter temperatures for caudex plants and cacti.
In spring 2025 I moved the older seedlings to a spot on the balcony with more direct sun, and their leaves turned purple. That was sun stress. They’re green again now.
A Welwitschia only ever makes two leaves, and they keep growing from the base, so leaf length is the easiest way to track progress. The two older seedlings have leaves about 7 inches (18 cm) long, and the two younger ones about 4 inches (10 cm).
This winter in the greenhouse
This winter the greenhouse will be heated with an electric heater on a thermostat set to 8°C (46°F), so the seedlings won’t go on heat mats. I’ll keep the same watering approach: less than in summer, but never letting the bottom of the pot dry out.
What’s next
Next spring I’ll repot both pairs into bigger pots and a 50/50 mineral and organic mix. With that, I’m hoping summer watering can drop to once a week. I’ll write that up in April. Next week’s post is about how I’m insulating and heating the greenhouse for its first winter.