Which side of maple trees produces syrup best? How to decide the best place to tap

I have recently started to enjoy the hobby of making maple syrup from two ordinary maple trees in my backyard, but being a guy who grew up in a city, I don’t exactly have a wealth of farming and sugaring knowledge to draw from. Read, fire, aim was how I decided where to tap my trees. But now that we’re in the off-season, I did some more research to make a more informed decision, and I’m sharing that now with you here.

The side of the maple tree that produces syrup best is the side of the tree that is currently experiencing the ideal conditions (internal temperature, primarily), for sap flow. Those conditions will vary from hour to hour, day to day, and year to year based on weather patterns, outside temperature, seasonality, and sunlight. But according to one study, no single side is more productive than the others over long periods of time.

How temperature within the tree affects sap production

In order for the sap to flow, two things have to happen.

1. The water held in the roots has to freeze (typically at night)
2. The temperature inside the tree needs to warm up to thaw that frozen sap water

When the water inside the roots of the tree freezes, the water forms ice crystals, which take up more space than the liquid water. Based on the fluid dynamics of how nutrients are circulated in a tree, this creates a stored-up energy dynamic. So when the temperature inside the tree warms up to the right range, the sugary sap runs up the tree to all the branches and out your tap hole.

The weather and outside hourly temperatures play an important role in sap production, but those are not the only factors.

How sunlight affects which side of maple trees produces syrup best

Ever sit or stand with the sunlight hitting your face and body? How does it make you feel? It might do you some emotional good, but the answer I’m looking for here is that it literally makes you feel warmer, right? Well, that’s because sunlight very warms things up, including your maple tree.

Sunlight plays a significant role in warming up the tree. Direct sun on the tree in the early part of a cold morning will warm that side of the tree up to the sweet spot before the shaded side. Sunlight can also overheat one side when the outside temperature is already in the 40s or 50s, while the other side is producing significant amounts of sap.

Scenario planning: which side is favored early in the season?

If there is one thing we know to be true–it is that the weather is often unpredictable. But if we simplify things and just think about the general weather trend, sap season starts as the weather warms up and Winter transitions into Spring. So theoretically, the early part of the season should be colder than the later part of the season.

For maple syrup harvesting seasons that follow that traditional, linear progression–the South-facing side of the tree outperforms the North-facing side.

Which side is favored late in the season?

Traditionally speaking the late season is characterized by warmer weather. At this time of the year, the extra sunlight on the South-facing side works against sap production and the Northern side is more likely to be a big producer.

Which side is best on cold days?

On cold days, the extra sunlight that a South-facing side gets can mean the difference between sap that is frozen (and not running) and running a little–or between a slow trickle and a faucet–if those precious few degrees put things in the sugar zone.

Which side is best on warm days?

On warm days, where the weather already puts the temperature in the sugar zone, the shadier sides of the tree (Northerly-facing) will probably deliver more sap.

So which side is best?

That brings us back to the premise of the entire article here–which side is best? Hopefully, you can tell by now, this is an equation that would take a lot of computer power to maximize and predict in advance of the season.

What do the data say?

According to a study from the Farming, Journal of Northeast Agriculture, the author reports that when you add up all the sap yields from each year, there is often a winning and losing side–but that over the long haul, things work out to be about even in the end.  Since you won’t know what type of weather and season to expect, you won’t know which side to drill when it comes time.

Which side is best for the tree?

If you are appropriately conservation-minded and follow the tried and true guidelines about how many taps to place on a single tree, making maple syrup is sustainable and should not damage the tree in any meaningful way. But the fact remains that each hole you drill into the trunk is an injury to the tree. Therefore, it is likely best for the tree to spread out the damage as much as possible.

Does it matter whether there is a big root or big branch?

One of my first theories (not supported by any evidence) was that big branches probably need and get more sap than smaller branches. So I aimed for the middle of the trunk under a big branch with one tap and then placed the second tap as far away as I could get and still reach the same bucket with a drop line–but they were both mostly on the Eastern-facing side of the tree, more or less. As best I could tell, there was no meaningful difference in the amount of sap that flowed under the big branch vs. the other hole.

I couldn’t find any other data to confirm or refute the ‘big branch’ or ‘big root’ hypothesis, but given the note above about what’s best for the tree–it doesn’t seem like favoring a large branch is all that important of an idea, if you plan to tap the tree more than once.

Conclusion

Which side of maple trees produces syrup best?  I didn’t want to start out this article by saying…it depends…but at this point in the article, you’ve likely reached that conclusion. So what are you or I to do with all of this information. I’ll let you know where I’m netting out–and I’d love it if you would leave a comment below, to share if you’re reaching the same conclusion.

If we account for:

1. The facts that North and South facing should each be advantageous and disadvantageous under different conditions
2. We won’t be able to predict what type of season we are going to have
3. Understanding that if we pick a consistent approach, it will all work out in the end

We probably should choose to prioritize the health and vigor of the tree as the most important factor, which means we should pick the side that currently has the least injury or the side farthest from the most recent injury, and rotate each year.

If we have the opportunity to place more than a single tap:

1. We have the luxury of hedging our bets. Why risk being 100% wrong when we can guarantee 50% right?

My approach, moving forward, will be to spread the love and the taps to achieve some Norther and Southern exposure across more than one tap.

Where do you plan to put your taps?

Next questions: What to read next

Now that you know what factors to consider and how to decide which side to place the tap, you may want to read these next two articles:

When is the best time to tap a maple tree

How to tap a maple tree

References

Wilmot, Timothy. “Which side of the tree should you tap?” Farming, Journal of Northeast Agriculture. October 1, 2009