Tree Tapping and Maple Syrup

Ever really think about how maple syrup is made? It is many people’s favorite breakfast accoutrement, but most do not consider the story behind it. Well it comes from OCF’s oldest friend, the tree! Today on the blog we learn all about tree tapping and the process of creating maple syrup.

For starters, what trees can be tapped to make maple syrup? Maple trees of course! The syrup actually comes from the sap contained in these trees. The trees definitely need to be healthy and free of damage or disease to collect their sap, but size is also an important detail to account for when it comes to tapping trees. The tree must be mature if it is to be tapped for its sap. The minimum diameter size required is 1 foot. If the maple tree has a diameter of roughly 12 to 20 inches, it can be tapped only once. If the diameter is between 21 and 27 inches it can be tapped twice. Once the tree’s diameter surpasses 27 inches, it can be tapped three times. 

There are actually four main types of maple trees used for syrup making. They are: sugar, black, red, and silver maples. The sugar maple is, naturally, the best for making maple syrup. This is because it has a high sugar content. Sugar maples are predominately found in Canada and the northeastern United States, but can also be found as far west as Minnesota and as far south as Tennessee. These trees do well in various soils, but dislike very wet or very dry conditions. The black maple is the second most favorable for syrup making, as it has the second highest sugar content in its sap. Its growth range is more limited however, found within Canada in southeastern Quebec as well as the USA amongst central Wisconsin and down south to Tennessee. Coming in third is the red maple, which has a lower sugar content – but still makes great quality syrup. A pro of this tree is that it grows almost anywhere. It can be found growing all the way down in Florida and as far west as Texas. Lastly, silver maples can also make syrup but are these least desirable for this process – simply due to their low sugar content. As they grow early on in spring their sap can evaporate before being tapped. These trees do however have a large growth range similar to red maples. 

Fun Fact: While not one of these four popularly used types, the bigleaf maple, acer macrophyllum - which is found here on the Pacific coast - can also be used to make delicious syrup!

Now that you’ve learned about different types of maples, let’s get down to the details. First off, when is a good time to tap trees for sap? The ideal timeframe is from the end of January through the end of February. It is peak season when temperatures drop below freezing at night, but stay above freezing during the day. Secondly, how exactly does one tap a tree? Believe it or not, a power drill is used to drill a small hole in the tree. The drill bit size must match the size of the spile, which is the spout like instrument put into the tree that acts as a funnel to collect the sap into a bucket. The hole is created at a upward angle to allow sap to flow down via gravity. The hole goes into the xylem layer of the tree. Then the spile is hammered in and the collection bucket is hung. Sap flows out during the day when temperatures are above freezing. On average, 6 – 10 gallons of sap are collected in a syrup season.

How does sap become syrup? Initially, the sap is filtered through both a coarse and fine filter to remove debris. Then, it gets boiled. This is done at a temperature range of 212°F-218°F. This boiling will kill any bacteria present in the sap. As it is boiled, much of the sap evaporates. The sugars are then condensed and the texture begins to thicken. This liquid is then transferred to a stove top to complete its last step in its transformation to what we all know as “syrup”. This finished product is a ratio of about 67% sugar and 33% water. It is then filtered a final time and bottled while still hot. Bottling it while hot allows it to seal better and be stored at room temperate. Syrup that is bottled while cooled must always remain in the fridge or freezer. 

Fun fact: What many people do not realize is that it takes approximately 40 gallons of sap to make 1 gallon of syrup. How crazy is that!

Book Review: Like a Tree: How Trees, Women, and Tree People Can Save the Planet

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This book is for anyone that cares about the future of life on this planet, especially for people like myself who admire trees. Bolen offers a larger consciousness of our connection to trees and expresses that now is the time to honor and protect them. 

The book begins with her observation that there are "tree people", and "not-tree people". A tree person has positive feelings for individual trees and an appreciation of trees as a species while the latter does not. She goes on to describe the many ways "tree people" have come to be through shared life experiences. A tree person may have childhood recollections of trees being amongst their imaginative play, a person who seeks the comfort of a tree grove during uncertain times, and may understand why someone will stand in front of a tree in order to protect it from being cut down. Bolen provides a wealth of information about tree anatomy and physiology, introduces what tropical and boreal rainforests are, their health status and efforts to save them. She calls on us readers to discover an assignment that is personal and motivated by love and says that a tree person has the potential to become a tree activist at any age. She kindly provides us with role models of 'Activism with Heart' through storytelling. 

"Women have long been defenders of our forest. They've recognized that when forests fall, the livelihoods of local communities fall with them. Animals flee, soil quality thins, floods and landslides increase, and carbon-sequestering canopies are lost. Whether planting new trees or starting sustainable economic endeavors, women are regenerating the 'lungs of the Earth'"(Like a Tree, 2011, pp. 183)

Bolen speaks about how women, like trees, are devalued and exploited and advocates that the fate of forests and women are intertwined. She informs us that deforestation combined with population growth contributes to climate change. "Might reforestation and reproductive rights go hand in hand?" She also examines the female brain circuitry, hormonal physiology, and research that supports the need for women to become a force of change because of innate talents and abilities. 

Throughout the book, Bolen uses "like" as a simile to describe the similarities between ourselves, trees and associated symbols from different perspectives. The chapter heading, "Symbolic like a tree" explores mythic, and archetypical, religious, cosmic, and personal symbols. She also invites images of trees to come to the mind, and evoke soulful memories that help us connect to our interdependence. 

"Like a Tree" has validated my role in tree activism, and I conclude with a heightened awareness of the power of collective and individual efforts.

Bare Roots: Frequently Asked Questions

Q: What is a bare root tree?

A bare root tree is a tree that is harvested from the ground for the purpose of transporting it so that it can then be either re-planted or potted. For our purposes at the nursery, the bare root trees that get shipped in will be planted into 15 gallon pots.

Q: How many trees do we receive for bare roots?

We have received anywhere from 1200-1500 bare root trees for the past few bare root seasons. This number can change depending on the demand and stock remaining in our nursery. In anticipation of this large delivery, considerable time and volunteer hours have been dedicated to rearranging the trees already at the nursery in order to make room for the new ones. Despite the ample amount of new trees, our hope is to incorporate them into the nursery as smoothly as possible.

Q: Where do the bare root trees come from? How far of a distance do they travel?

The trees come from J. Frank Schmidt & Son Co., a wholesale nursery located in Canby, Oregon. The distance between San Jose and J. Frank Schmidt & Son Co. is about 645 miles. You can learn more about the nursery, which distributes a significant percentage of its deciduous trees to nurseries throughout western North America and Canada, here. In order to preserve the roots, the trees are bundled in twine and transported in a refrigerated truck. The same truck also stores several other bundles of bare roots to be distributed elsewhere. This may be hard to imagine considering our delivery alone consists of almost 1,600 trees, but the trees are so efficiently bundled that several deliveries can be made in one trip! Once the trees are successfully delivered, they can either be transplanted into 15-gallon pots or planted directly into the ground. Orchards often utilize bare root trees, in part because they are convenient, efficient and economical to transport. For our purposes at Our City Forest, considering the eventual goal is to sell these trees to residents, the bare root trees will be transplanted into 15-gallon pots.

Q: Are there particular types or species of trees that fare better through the bare root process (which includes harvesting, transporting, waiting and finally, transplanting) than others?

As far as the bare roots operation goes at OCF, our team only works with deciduous trees. This is because in order to be harvested from the ground and transferred hundreds of miles away and still survive, the trees must be dormant. The bare roots season happens when it does (mid-February to early March) in order to time planting with the dormant season. This year planting is set to start on February 21st.

Q: What kind of conditions do the trees require prior to being transplanted?

Before the arrival of the 1481 trees coming in this year, a trench will be built for the purpose of keeping the trees moist and cool--and therefore alive. The trench can be pictured as something like this: A long, raised pile of well-mixed soil amendment and mulch with a channel carved directly through the middle. The trees will then be propped into the trench, roots on the downside, and the exposed roots will be subsequently covered with the surrounding mulch-soil mix. Assuming it gets watered regularly (two times a day), the trench will serve as a temporary holding space that will protect and maintain the roots of the trees until it is their time to be potted. Provision of wet and cool conditions for the roots in the time between delivery and transplanting is crucial for the trees’ chance of a smooth transition and proper development. Dry roots on the other hand lead to decreased survivability.

Q: Why are the bare root trees we receive in February so important for the nursery?
The bare roots inflow makes up a huge percentage of the nursery tree stock.  Bare roots also allows for a more diverse stock. The nursery typically orders 20-30 different species of deciduous trees; this year we will be working with 27 different species! A primary goal of the nursery, and OCF as a whole, is to practice and promote diversity in urban forestry. Because the nursery supplies its stock with environmental health in mind, and therefore an effort to evade monoculture whilst promoting diversity, receiving a wide variety of bare root trees helps to support the OCF mission. The way in which bare roots is approached at OCF embraces, and therefore helps to advance, the reality that diverse forests--and ecosystems in general--embody longevity, health and beauty. Having said this, variety in species makes it possible to plant trees in a way that will enhance the biodiversity of the urban forest. The bare roots season is also important because it represents and encourages community involvement, building new connections, and educating about why the urban forest is a special part of our everyday lives.

 Q: What are the advantages and disadvantages of bare root trees?
Bare root trees are an economical and efficient way to stock the nursery. Buying trees as bare roots as opposed to already-potted trees from other nurseries is more cost-effective, especially taking into account the amount of trees we receive during bare roots. Transplanting bare root trees is efficient because these trees are much easier to transport and store than potted trees. The bare root plantings also allow for the team, and the volunteers learning from the team, to take special and specific care of each tree that they transplant (i.e. as opposed to a tree that is donated or sold to us from another nursery). In terms of disadvantages, one is that the timeline for growth can be challenging. For example, the maple, zelkova and elm tree species are typically ready to be planted about three to four months after they are potted. Ginkgo and linden trees, conversely, take longer (about 6 months) to root. This difference in development among species can cause inconvenience because certain species may not coincide with demand. Another disadvantage is that the process does not include a single evergreen tree, so the evergreen population must be supplemented from other sources.

Q: How well have the bare root trees from last year grown and developed thus far?
The survival rate among last year’s bare root stock is 95 percent. As of now, these trees are healthily rooted and ready to be planted! 

Q: What role do volunteers play in the bare roots process?
During the bare roots rush, volunteer recruitment efforts at the nursery are more important than ever! This is because there is such a large number of trees to transplant, and the OCF team can use as much help as it can get. Because of this, bare roots implements two volunteer shifts per day--one in the morning and one in the afternoon. As we are a community nursery, anyone looking for a meaningful way to help their environment is welcome to participate!

Q: How does bare roots strengthen community engagement and learning?
Bare roots is a perfect opportunity to build upon the interrelations of our San Jose community in a way that provides insight into what it takes to grow high quality trees. During bare roots, all kinds of people come together for a common cause--from corporate groups, to students, to families and friends. The aspect of community participation in bare roots is also so exciting because the same volunteers who help transplant the trees will have the opportunity later on to plant the same trees throughout their city!