I want to know what trees produce maple syrup, and if they’ll grow in the Pacific Northwest. Also, will I be able to get syrup from them in our climate?
I believe that any of the syrup-producing maples will grow here, but syrup production might not be possible as it depends on specific weather conditions. Massachusetts Maple Producers Association’s website lists and describes the main species of maple used for syrup (including Acer saccharum, Acer rubrum, Acer saccharinum, and Acer negundo.
An article in Wikipedia describes the type of weather conditions needed for syrup production.
Excerpt:
“Production is concentrated in February, March, and April, depending on local weather conditions. Freezing nights and warm days are needed to induce sap flows. The change in temperature from above to below freezing causes water uptake from the soil, and temperatures above freezing cause a stem pressure to develop, which, along with gravity, causes sap to flow out of tapholes or other wounds in the stem or branches.”
Massachusetts Maple Producers Association describes temperature’s effect on sap flow:
Excerpt:
“Sap flow from sugar maples is entirely temperature dependent. A rise in temperature of the sapwood to above 32 degrees F. causes a positive pressure within the wood. This pressure produces the sap flow. Many people assume that maple sap flows up from the tree’s roots on warm days. Actually, on warm spring days which follow cold nights, sap can flow down from the maple tree’s branches and then out the spout. The sap can also flows back and forth laterally within the tree. It will flow out a hole drilled into the tree or out through a broken or cut branch. The internal pressure of the tree, when it is greater than the atmospheric pressure, causes the sap to flow out, much the same way blood flows out of a cut. If you visualize a portion of a tree trunk as being under positive pressure, a taphole is like a leak, sap moves towards the point of lowest pressure from all directions.”
There is a tree description for Acer saccharum from the University of Washington’s Campus Tree Tour:
“The chief attributes of this species are its major role as an important component of forests in much of eastern North America, its warm orange fall color, its highly useful wood, and its sweet sap. When the trees are leafless in late winter, their sap rises and descends with the temperature, and people extract it to use in making syrup or sugar, whose maple flavor is one of the unique delights of life. Our climate is too warm in winter for commercially worthwhile sap harvest, but the trees grow well here.”
I think that our winters and early springs are not usually cold enough to be optimal for maple sugaring. However, I did find an archived article in Mother Earth News (1979) about tapping trees for syrup in the Pacific Northwest. There is also research being done at the University of Washington’s School of Environmental and Forest Sciences to explore the feasibility of producing maple syrup from bigleaf maples (Acer macrophyllum).