Growing Giant Sequoia Trees From Seed

Giant sequoia trees (Sequoiadendron giganteum) are the largest living things on Earth.   They can live for thousands of years, reach almost three hundred feet in height, resist droughts and forest fires. The single largest sequoia tree now living, General Sherman, has sequestered over a lifetime of carbon emissions by the average American.   What is more, giant sequoias can grow throughout much of the world in temperate regions, including most of the continental United States, so long as they have sufficient water (around 30 inches or 762 mm each year).  Sequoias are common in Britain, but are also in mainland Europe, New Zealand, Australia, Japan, Canada, and almost every state in the U.S.

Establishing sequoias is very difficult, and with trial and error you can expect years of frustration, even if you buy saplings rather than seeds. Even with saplings we didn't have any success establishing sequoias outside in the Midwest until we started using the Waterboxx PlantCocoon to grow sequoias for the first few years.  Since starting to use the Waterboxx PlantCocoon, we have had 100% success, detailed here and here.

As sequoias proved such fun to plant and are so beneficial to the environment, we wanted to know if we could grow sequoia trees from seed.  We had tried this before, but had very poor germination rates (around ~1%), and many of our trees that did germinate soon died.  We were determined to try again, but to follow the best advice available for growing these seeds.

Sequoia seeds are tiny - here is an average sized one on a fingertip before planting.  It is hardly believable that these become the largest living things on Earth.

We bought 500 giant sequoia seeds from MySeeds.co, on Amazon.com here (or more cheaply from their website here).  Sequoia seeds need a very specific process mimicking their natural environment to germinate (including a wet "fall" and cold "winter"), so we tried to replicate that in as short a period as possible.  To start, we laid our seeds on a paper towel and moistened them with water (distilled water for best results as it doesn't contain mold).

Seeds on July 16, 2015, right after getting them in the mail.  Our biggest problem was having the patience to not plant before "hardening" for a month in the fridge.  

We covered these seeds with another moist paper towel, and them put them on a portion of a paper plate.  We then put these in a clean, sealed plastic bag.  This simulated our wet "fall", in order to reawaken the seeds.  For our winter, we placed this plastic bag in the vegetable crisper in the fridge for 30 days.

After 30 days, we removed our seeds.  We started with 500 seeds, but given our poor germination rate before, we didn't expect most to produce anything.  We took about half of these seeds to be planted.  We set up a Cone-tainer rack filled with 98 soil holding cone-tainers (both available here).  We filled these full of potting soil.  For about half of the cone-tainers, we also added some vermiculite, which is excellent at holding moisture.  We then took the very small seeds, and added them to the top of the soil mixture.  For half of the cone-tainers, we used only one seed, and for the other half we used three to four.  We pushed the seeds down slightly into the soil, but we did not bury the seeds.

Our 98 Cone-tainers in a tray, with our seeds just planted, on August 18, 2015.  The vermiculite containing Cone-tainers are white on top.

We waited about two weeks, but didn't see any of the promised germination.  We thought that perhaps nights were getting too cool (sometimes into the upper 50s Fahrenheit), so we put a cold frame we had previously built over the sequoias seeds.

Within two days, we started to see germination of our tiny trees.  We did our best to keep the tiny seedling moist without over watering.

Tiny sequoia trees, just growing from seed on August 31, 2015

We had about 25% germination in our first round. We wanted to have a giant Sequoia tree growing from each Cone-Tainer, so we planted more seeds in each Cone-Tainer that didn't have one germinate.

We did have a few Cone-Tainers with more than two sequoias germinate. We wanted didn't want competition to hurt both sequoias, so we removed the smaller sequoia seedling so the larger could continue to grow unabated.  When we removed the smaller sequoia, what we found was astounding (to us, at least).  Giant sequoias send down a true tap root!   This is incredible, as many trees just send out shallow, lateral, fibrous roots.  This true tap root means sequoias can tap deep sources or water (like water held in capillary channels) as well as underground aquifers.  This means that sequoias will be able to withstand droughts very well.  This only makes sense as many sequoias have lived for three millennia, through many droughts, in California.

A tiny sequoia sapling, a little over a month (9/26/15) after planting, with a taproot over three times the length of the trunk.  These tap roots enable sequoias to survive very long periods without rain.

We are growing these sequoias from seed in Central Indiana, which has harsh winters, so we decided to move our saplings inside to a window sill over the Fall and Winter and provide a little artificial light to speed up growth.  There is a chance this may disrupt the seasonal rhythm of the plant, but we judged this risk as lower than the risk from the freezing.

The sequoias inside (all moved close to get the most light) on October 3, 2015.  We have had about a 33% germination rate so far - not bad for this very difficult to start tree.

We are very impressed that the eventual structure (and beautiful red trunk) has already begun to become evident.

A sequoia about 5 weeks old - we hope this sequoia is 10 inches tall by spring to it can be planted outside with the Waterboxx PlantCocoon.

At this point (October 6, 2015), we still have about 70% of our Cone-tainers without any sequoia seedlings.  This means our germination and survival rate has been somewhere around 15% (because we planted about two seeds per Cone-tainer, on average).  We want each Cone-tainer to have one sequoia, so we planted the most of the remaining seeds into the empty Cone-tainers.  We did save a few seeds just in case none germinated in some Cone-tainers.  

A sequoia at about 10 weeks - again perhaps doubled in size over the past 5 weeks.

By late November, we have planted all 500 seeds and have 50 living sequoia seedlings, for a germination rate of 10%.  As this is our second planting, and we had a germination and early survival rate of 0% previously, we are well pleased.  We are supplementing sunlight with full spectrum CFL light (purchased before full spectrum LEDs were available), and see the smaller sequoias grow ~5% per day - a very healthy growth rate indeed.

Our sequoia seedlings 4 months and 11 days after planting.  We still have 48 living sequoias, with two more lost to damping off.  Our tallest tree is about 3.5 inches, which should put us in range of the desired 10 inches by April with our continued artificial light.

Right now (late March 2016) we have had greatly decreased survival in the late spring.  We asked our friend Joe Welker of Giant-Sequoia.com why this was, and he believed it was because we grew indoors.  We are down to only 10 sequoias, hardly satisfying,

Our sequoias on March 29, 2016 - only 10 left.  We will try continue growing these but try again with a new crop of seeds in a few weeks - outdoors.  

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We plan to start a new crop in outdoors in early June.  The things we will change with this next crop:
1. We will plant using larger size cone-tainers
2. We will plant outdoors
3. We will use only distilled water initially to prevent fungal diseases causing "damping off"
4.  We will keep the sequoias outside all winter (but in a cold frame to prevent desiccation from the wind).

You can see our next trial (this time with 2000 sequoia seeds) here.


We hope to see these sequoias grow to the point they can be transplanted outdoors with the Waterboxx PlantCocoon®.  They will need to be about 10-15 inches tall at that time.  We are growing these sequoias for donation to a few growing partners in the South and Midwest - we will post those plantings online when pictures are available.

Our greater hope is to see giant sequoias planted on public and private property throughout the United States and rest of the world.  This tree grows so large, so fast, and lives so long, that it may be one of the few affordable ways to decrease carbon dioxide in the atmosphere, counteracting the problems caused by excessive carbon dioxide.

We will continue to update this post with our sequoia from seed progress.  We would love to hear your comments below.

If you would like to plant sequoias you already have outside, with the Waterboxx, you can buy a Waterboxx PlantCocoon here.

The Planet's Lungs: Planting Giant Sequoias To Combat Carbon Dioxide

Carbon dioxide concentration in the atmosphere is increasing.  This is not controversial.  Global warming has been cited as the most dire problem from this increasing concentration of atmospheric carbon dioxide, but other problems (like ocean acidification) clearly exist.  Almost all of the proposed solutions to this carbon dioxide increase have been foolish and harmful to human prosperity - limiting driving, flying, air conditioning, home sizes, etc.  Few are discussing a much better solution that improves rather than worsens our living standards- planting very long lived and massive trees to absorb and store carbon dioxide.

Carbon dioxide concentration in the atmosphere as measured by the Mauna Loa Observatory on Hawaii.From NOAA, available at http://www.esrl.noaa.gov/gmd/ccgg/trends/.  The sawtooth pattern of the graph likely reflects the absorption of carbon dioxide by vegetation throughout the year.

The largest tree (and living thing, for that matter) on Earth is the giant sequoia tree (Sequoiadendron giganteum), specifically a single tree called "General Sherman".  We wished to calculate how much carbon dioxide a sequoia tree could conceivably sequester or "lock up" in a best case scenario.  Sequoias are ideal for sequestering carbon dioxide because of their great volume, extremely long lifespan (several thousand years), and the wide range in which they can be grown.  We are currently growing two giant sequoias in Indiana, which is hardly native habitat for the sequoia (native habitat is a small portion of California's Sierra Nevada).  We had planted 5 sequoias outdoors previously in our state, but saw all die during the summer dry spell - even with frequent watering.  We finally decided to use a device called the Groasis Waterboxx PlantCocoon® to grow our sequoias outdoors, with 100% success, in two different parts of our state.

We went through a fair amount of effort to determine how much carbon dioxide a giant sequoia can sequester.  We will spare you the details of this calculation here, but please see our footnote for our sources and calculations.

The "General Sherman" sequoia tree in California is the largest living thing on Earth by volume.  Its volume of 52,500 cubic feet, or about 1486 cubic meters, contains over one million kilograms (and over 2.2 million pounds) of stored carbon.  This volume of stored carbon pulled over 1400 metric tons of carbon dioxide out of the atmosphere.

Americans, on average, produce 16.6 metric tons of carbon dioxide emissions per year (although this number has been decreasing recently due to efficiency gains).  The General Sherman sequoia is so large that as a single tree it has stored about 86 years worth of a person's carbon emissions.  In other words, one very large tree has been able to counteract over a lifetime of carbon emissions for the average American.

The General Sherman  Giant Sequoia Tree, from National Park Service, found at http://www.nps.gov/seki/learn/nature/sherman.htm, public domain

These facts about the largest giant sequoia would be interesting but not particularly actionable if not for one simple fact.  The giant sequoia can be grown in most of the United States - not just California.  We ourselves are growing two giant sequoias in Indiana, both started with the Waterboxx PlantCocoon®.  The sequoia's main requirement is sufficient water, and its water needs can be significant.  However, the need for consistent water is most critical during the first few years of a sequoia's life outdoors.  We have found that due to soil evaporation, we could not manually water sequoias enough for them to stay alive.  Some other system was needed to prevent evaporation and ensure sufficient water available to the roots.  It was our interest in planting sequoias in a better way that got us interested in the Groasis Waterboxx PlantCocoon®.  One of our sequoias has now graduated from the Waterboxx PlantCocoon® - meaning the Waterboxx PlantCocoon® has been removed and used for other plants.  The tree is doing well even though we haven't manually watered it, even once. It takes about 18-24 months to establish a small (6 inch) sequoia with the Waterboxx PlantCocoon® in our state.  You can see our two sequoias in the pictures below.  Neither of these trees has had any water from us or any sort of irrigation after initial planting and set up with the Waterboxx PlantCocoon®.

Our giant sequoia was planted just outside Indianapolis, with these pictures above showing two years of growth.  This tree is now over a meter tall, with no watering at all after planting with the Waterboxx PlantCocoon®.  Even after the Waterboxx PlantCocoon® was removed, no watering was needed due to the deeper roots established by the tool.

This giant sequoia seen above, planted in Southern Indiana, was smaller when transplanted outdoors with the Waterboxx PlantCocoon®. In the 25 month time span seen in the photographs, it has dramatically increased in size, and will soon be able to survive without help.  

Regardless of your stance on global warming, increasing carbon dioxide in the atmosphere poses other risks (like ocean acidification mentioned above) as well as some benefits (like faster plant growth).  We can take advantage of both of these by planting giant sequoias.  If every set of grandparents came together to plant one sequoia each for every new grandchild in their family (for a total of two sequoias per child), that child's carbon dioxide emissions would likely be offset by the sequoias, and the carbon would be stored for thousands of years.  Also, we would find our neighborhoods more stately and shaded from these monumental trees.

If you are interested in trying to grow a giant sequoia, our preferred source is Giant-Sequoia.com.  To buy the Waterboxx, visit us at DewHarvest.com.

Footnote: Our Calculations and Sources 
Note: we use American mathematical nomenclature here (commas to separate 1000s, periods to indicate decimals)

When calculating carbon dioxide sequestered by a sequoia, it is first necessary to have the density of sequoia wood.  We were only able to find this information with great difficulty here after much searching.  We did also receive a generous sample of sequoia wood from our friend Joe Welker at giant-sequoia.com (where we bought our sequoia trees).  The measured density for a small piece of sequoia wood containing bark was approximately 0.48 grams/mL.  We obtained this by measuring a small piece of sequoia wood (36 grams) on a very accurate postal scale.  We then submerged this same piece in a graduated cylinder, which displaced 75 mL.  36/75 = .0.48g/mL which equals 0.48 g/cc as one milliliter is equal to one cubic centimeter, by convention.

This density of 0.48 g/cc is within the range of densities reported by Wolfgang Knigge in his scientific paper Giant Sequoia in Europe,  http://www.fs.fed.us/psw/publications/documents/psw_gtr151/psw_gtr151_06_knigge.pdf) . His reported densities found average values of 0.345 g/cc in European giant sequoias and 0.369 g/cc in California giant sequoias.  Our density of 0.48 g/cc converts to 480 kg//m^3 (the math for this conversion is 0.48g/cc x 1,000,000 cc/m^3.  This result is then multiplied by 1 kg/1000 g, equaling 480 kg/m^3).

Next we need to calculate how much mass the largest living sequoia tree, General Sherman, contains.  According to the National Park Service, the General Sherman sequoia has a volume of 1,486.6 cubic meters (http://www.nps.gov/seki/learn/nature/sherman.htm).  To get total mass of this tree, we multiply 1486.6 m^3 by 480kg/m^3.  This gives us a total mass of 713,568 kg for General Sherman.

This mass is of course not all carbon - much being oxygen, nitrogen, and other elements.  Most trees are about 50% carbon by mass.  However, as giant sequoias have more heartwood (more durable wood in the center of the trunk) than sapwood, and heartwood has a slightly higher carbon content, this value may be too low for sequoias.  According to Sean Thomas in his Paper Carbon Content of Tree Tissues: A Synthesis (See section 4.1, available here: http://www.mdpi.com/1999-4907/3/2/332/htm), giant sequoias are approximately 55% carbon by mass.  When we multiple our calculated mass for General Sherman of 713,568 kg x .55, we get a carbon mass of 392,462 kg.

We next need to convert the mass of carbon into metric tons, so we divide 392,462 kg by 1000 to get a value of 392.4 metric tons or carbon stored in General Sherman.

However, carbon is not the same as carbon dioxide.  Carbon dioxide has one carbon atom and two oxygen atoms per molecule.  Trees absorb the carbon when growing while (mostly) emitting the oxygen.  The atomic weight of carbon is 12.001115, while the atomic weight of oxygen is 15.9994. So the total atomic weight of CO2 is 43.999915.  With a little algebra, we see that since the ratio of carbon dioxide to carbon is 43.999915/12.001115 or 3.6663 units of carbon in the tree for every unit of carbon dioxide removed from the atmosphere.  We obtained this information from the Broward County Florida Climate Change website (https://www.broward.org/NaturalResources/ClimateChange/Documents/Calculating%20CO2%20Sequestration%20by%20Trees.pdf) as well as contact with Richard Campbell from Save The Redwoods).

We can thus multiply our total mass of carbon, 392.4 tons by our conversion factor 3.6663 from above to get 1438.892 total tons of CO2 removed by the General Sherman giant sequoia.

Americans, on average, produced 16.6 metric tons (or tonnes) of carbon dioxide per year in 2013 (the most recent year available) according to the Netherlands Envirornmental Assessment Agency (Table A1.2, page 49 found at http://edgar.jrc.ec.europa.eu/news_docs/jrc-2014-trends-in-global-co2-emissions-2014-report-93171.pdf).

When we divide 1438.892 metric tons of carbon dioxide removed by General Sherman by 16.6 metric tons, we get 86.7 years of CO2.  That is 86.7 years of carbon emissions sequestered in a single tree!  We find this number so impressive that we checked our math several times.

Caveats:  General Sherman is the largest sequoia now living, and any trees planted would be unlikely to get quite this large.  We chose this tree as good data was available on its volume, and as a vivid example.  Also, it likely took several hundred years to reach this size, with more carbon absorbed at larger sizes.  So any sequoias planted are unlikely to absorb a whole person's carbon dioxide output for several decades.  However, adults emit considerably more carbon dioxide than young children, so the growth and sequestration of a sequoia may roughly mirror a human's emissions.