Note: The original post below was made on Facebook on Saturday Sept 6, 2014, four years ago from the date of this blog post. The strong and moist remnants of Hurricane Norbert were approaching the desert southwest in the eastern Pacific Ocean, providing a greatly elevated chance of abundant rainfall across most of Arizona and nearby states. That did, in fact, come to pass and on Sunday and Monday, Sept 7 and 8, my gardens here at D:F Ranch received over three inches of rainfall. That event will be available in an upcoming post, but for now, let’s address the distribution of Joshua tree seeds into the wilderness to help the species carry on….

Tonight I am inspired to hull out a bunch of these Joshua tree seed pods (Yucca brevifolia) because the rainy forecast for Sunday through Tuesday should be propitious for their germination once I scatter them into the desert. I gathered these buckets full of pods in June 2013 last year after the local Joshua tree forest bloomed abundantly and successfully set hundreds of capsules on most trees. I’ve been saving them for a rainy day (hah!) inside my shed, and my goal is to save some for sale or propagation in nurseries, and distribute the rest back into the desert to help recruit the next generation.

Joshua trees reproduce fairly slowly and seedling mortality is high, in no small part because the large, flat, black seeds are highly visible against pale sandy desert soil, and are much coveted by desert animals as a food source. My hope is that by saving them for broadcasting just in advance of a significant desert rainfall, and by tossing the seeds into shrubbery where their odds of escaping the rigors of the heat and dryness and predation by seed eaters are best, that I can help along the wild population. So tonight is a night that I’ll be focusing on that. I hope the timing is right, and I wish a bon voyage to the little seeds as I send them off into the future. Pray for benevolent rains – the Biblical Joshua for whom these plants were named would want that too!

I cleaned about a bucket’s worth of large pods over the course of a few hours. The seeds are a lot of trouble to separate out – you have to pound the hard shelled pod with a hammer and then sort of scrape the seeds out with your fingers as you crush the placenta they are attached to. It’s much more difficult than gathering most yucca seeds (and agaves too) where the pods split open voluntarily and the seeds easily shake out with the motion of the wind, or manually. Of course that ease of separation means that with most other yuccas you need to be very on-the-spot with gathering them promptly, or else they’ll all blow away by the time you get to them casually. At least with Joshua trees you have a couple of months to harvest them, although rodents do climb the trees to access the pods, so you don’t have forever.

The yucca family has over 50 species, and the fruits are separated into those that have dehiscent pods that split open at maturity, and indehiscent pods that don’t. Joshua trees, Yucca baccata, and Y. schidigera are indehiscent species, while Y. glauca, Y. elata, and many others are dehiscent. If the seeds are black and full they are viable, and if they are white/yellow (infertile) or black and super-thin (eaten on by the yucca moth larvae, weevils, or other seed boring insects) they aren’t.

By contrast, I believe that almost all agaves (in the same family as yuccas, Agavaceae) have dehiscent pods – in fact I can’t actually think of any that don’t. But the yuccas have definite camps when it comes to seed release from the pods. I think a general rule is that most of the thinner-leaved yuccas are dehiscent, and the thick, sword-leaved yuccas are indehiscent. There are probably exceptions, but it may be a useful rule of thumb.

Writing from the perspective of 4 years later in September 2018, I hope that the generous rains that did fall with the remnants of Hurricane Norbert, and then again 10 days later with Hurricane Odile, did enable some successful reproduction of the Joshua tree seeds I scattered. Slow growth means that any seedlings that have managed to establish in the protective cover of shrubbery and debris piles where I made sure to hide the seeds will take some years, possibly a decade or more, to emerge. But if I do see a number of seedlings on my property and on neighboring lands starting, oh maybe about 2024, then I think I can trace at least a few of them to the thousands of seeds that I distributed.