Lauren and Sandra Mardonovich sow Tecate cypress seeds in long pots that provide spacious room for roots.
The Tecate cypress Hesperocyparis forbsiiis a tree found only in Southern California and northern Baja California, Mexico. It has a limited range and is fire dependent, which means the cypress needs fire to reproduce. The cones of this species are serotinous, which means the seeds are released by an ecological trigger (in this case, fire) instead of being released once they reach maturity. When the cones are exposed to heat, the resin that keeps them sealed is melted, the cone opens, and the seed is released. Without fire, the Tecate cypress keeps its seed bank within persistent cones in the tree canopy. When a fire burns a mature stand of Tecate cypress, new seedlings pop up in its place. If this second generation is burned before it reaches maturity, it could wipe out the entire population. There are only four stable populations remaining in California, three of which are in San Diego County. It is because of its limited range and risky reproduction technique that this tree is such a sensitive species.
Tecate cypress cones collected from Otay Mountain await processing.
The Applied Plant Ecology Division at the San Diego Zoo Institute for Conservation Research has partnered with the Nature Conservancy, the Bureau of Land Management, and the California Department of Fish and Game to preserve this unique species. The goal of the project is to provide a safe guard against high-frequency fires wiping out the population.
To do this, we collected enough seed from a mature population to have a portion for safe keeping in the Native Plant Seed Bank at the Safari Park and a portion that could be germinated and planted as a nursery stand. Cones were collected from Otay Mountain and processed at the State of California’s Lewis A. Morgan Reforestation Center. The processed cones resulted in thousands of seeds, and of those, a fraction was planted. From the planted seeds, we are hoping to get 400 to 500 seedlings.
Here's a close-up view of the seeds before being covered with soil.
Once the seedlings have grown to a suitable size, they will be planted at the Rancho Jamul Ecological Reserve. The planted cypress trees will be monitored over the next six months. These trees will be used as a sort of “plantation” where more seeds can be collected as needed in case the other stands burn before reaching sexual maturity.
Lauren Anderson is an intern at the San Diego Zoo Institute for Conservation Research through the Bureau of Land Management’s Seeds of Success Program. Read her previous post, The Desert: Blooms and Hail.
An interesting blog Lauren. How do you get the cones you collected to open. I gather you used heat, but how is this done without burning the cones?
Lee – Greetings. The Reforestation Center first soaked the cones in 92°C water for 24 hours. The cones were then surface-dried and placed into a drying chamber at 49°C for 4 hours. When the cones did not start to open , they used 52°C for about 8 hours and finally another day at 54°C. The cones that had partially opened received a final drying period at 52°C while the cones that had not opened went through another round of hot water soaking followed by drying at 52°C. So, you can see that the process was not just a single step. Once the cones were opened, they were tumbled to extract the seed and upgraded in an air separator to remove some empty seed. The finished seedlot had 42% germination, which is rather good for cypress seed.
When I lived in the United States before coming to Sweden 6 years ago, I was in El Cajon for 4 years, but prior to that I was in Anza CA (not Borrego). I collected seed from some of the populations mentioned for a couple of the larger native plant nurseries in So-Cal.
Back in the 1970s all the literature said Tecate Cypress was difficult as only 30% to 40% could be counted on to germinate. Times have changed. Back in 1979 I thought about the natural circumstances under which a Tecate Cypress seed would germinate. After using a Bar-B-Q grill filled with sticks and pines needles for a quick fast flash fire, and tin foil for which to place the cones inside of, I lit the fire which burned quickly & hot and in no time at all with the lid covered the cones opened radily. After gathering all the seeds which were hundreds, I’d put them in a cleaned mayonaise jar and pour hot water on them and let them cool over night soaking.
In the morning I’d drain out all the majority of the water, but leaving the seeds in the jarand closing the lid. Next step, put them in the fridge on a bottom shelf for 3 months exactly, then check them at the end of that 3rd month. What you will notice is that every single seed has it’s little germ swollen and white. This is the time to plant in the flat seed trays as you’ve referenced above. My germination rate has always been 100% – Okay Okay nothing’s perfect, so 99.9%
*smile*
Seriously though the numbers are ALWAYS extremely high. My potting soil always consisted of any good soil mix from a commercial producer and this added to vermiculite, the mix being 50%-50%. But more is needed as damping off is always a danger. I hated the dangerous fungicidal conventional science-based gases we used in school, so i use Hydrogen Peroxide. Tou can either get ready made common peroxide from the over the counter Rite-aid (whatever) and mix 50%-50% in a container for spraying or drench the potting media in the flats. After a day or so I’d plant the seedlings.
(BTW, I also have in the past made my own Hydrogen Peroxide from food grade powedered mix which can be obtained from a supplier, but that’s another option. The food grade doesn’t have the preservatives in it)
After the young trees are a few inches high and easy to work with, replant in 1 gallon pots. I always had to give many of them away. I even wrote about my experience with these trees on my blog. I wanted to recreate a Tecate Cypress forest woodland urban landscape feature and did so in my mum’s yard. Ran into soil structural problems though. My mum’s place is a great sandy loam soil from an ancient aluvial fan coming out of one of the canyons on Rattlesnake Mountain in El Cajon near Pepper Drive School. The area use to be all orange groves. Perfect garden soil, but too soft for fast growing cypress saplings which grow fast, even without much watering and easily blown over in a winter wind storm even there. I also mycorrhizae innoculate also.
Sorry for the rant, but that’s my experience.
Kevin
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I enjoyed reading and learning about the cypress, very interesting and educating.
I enjoyed reading and learning about the Cypress seed.
I planted one in my yard a couple years ago. It was fairly big in a five gallon pot. It squatted there for a least a year. Now it’s growing. I think it did three feet just with winter rains. It’s a very good looking plant. I am thinking of planting some more in another part of my yard.
Too zealous of a water schedule can make them grow fast but then you have the toppling problem. When I water, I put the hose a few feet away to encourage the roots to spread out. Now that it’s grown quite a bit, I think I won’t need to water it. It will steal water from plants several feet away.
It’s done pretty well with my inconsistent attention. A good easy evergreen that should be planted more in drier gardens.
Would this tree be appropriate to use as an hedge? We live along Avocado Blvd. in La Mesa. We are slowly removing some pines. We are looking for something that is native and would provide us with added noise reduction and privacy.
I’ve been working with this species for a while now, visited all known groves of them in the United STates. The one near Corona, in Coal Canyon and on Sierra Peak, seems to be slightly genetically distinct but no definite genetic analysis (done by doing pcr tests on essential oil) has been done to define this. Who knows how long it has been separated genetically from the other groves a hundred miles south. This tree almost needs no stratification to germinate. The method I used for extracting seed was to just place the cones in a paper bag on the dashboard of a car parked in the sun on a hot day. But really, there are many ways to get the cones to open, jsut be creative.
They grow fast until they reach fifteen or twenty feet then slow down a bit. Yes, planted in too rich or soft a soil they tend to topple when the soil gets saturated. They smell very frgrant, too. All they need is full sun and arid summers.