When is the best time to tap a maple tree in Southeastern Pennsylvania?
That was my number one question when I first decided to get started in this hobby. When do you put the tap in the tree?
Unfortunately, when I searched around, all I found about the topic was general advice.
Most of the advice I found stated that the ideal time to tap a maple tree is when the sap is flowing…
Sap flows when the nighttime temperatures dip below freezing, and the daytime temperatures get into the 40s.
This process of freezing and thawing causes water pressure in the tree that produces the sap flow we want.
Once the temperature gets too warm (if it doesn’t get below freezing at night), the sap flow stops, ending the season.
Well, that helped…a little…but it still didn’t answer my question. I found out there are also a few other considerations as well.
It depends on what type of trees you have, certain types of maple trees will produce buds sooner than others.
Once the buds emerge from the branches, it turns the flavor of the sap.
I found out that taps dry out about ~8-10 weeks after starting them.
When did I tap my trees?
I have 2 silver maple trees at my house, not sugar maples (which bud and end the season a bit earlier than sugar maples). My gut also told me that once April rolls around in the Philadelphia metro area, the nights don’t dip into the 20s all that often, so I decided to go as early as I could.
The first weather report that looked like it would give me a few days was the week of January 19-25–so I tapped my trees on January 19, 2019.
Was it the best time to tap a maple tree in Southeastern PA? Answering that question is what the purpose of the rest of this article is about.
The only way to determine when the best time to tap was, to take good notes and look back over the season. Here is my account of the season.
Week 1: January 19-25
This adventure started on January 19th. I had cabin fever, some extra free time on the weekend, and the weather forecast warmed up.
See for yourself:
From the looks of it, I thought there would be 3 good maple sap days: Sunday, Wednesday, Thursday.
Here is how that sap collection really turned out. The tables in this report show how many ounces of sap were collected each week. I did not typically measure the ounces directly, I generally estimated.
|Jan 19||Jan 20||Jan 21||Jan 22||Jan 23||Jan 24||Jan 25|
|Ounces of sap||0||0||18||0||0||0||104|
As you can tell from the report, however, the sap wasn’t really flowing that well yet, although it did yield just under 1 gallon of sap for the week.
Week 2 January 26 – Feb 1
This week started out warm and then got bitterly cold towards the end of the week. In the news, they called it a polar vortex–a front of cold air that shot down from the North Pole.
It actually got even colder than this report shows–the temperature was below zero for a couple of the days. Here is what the sap collecting looked like:
|Jan 26||Jan 27||Jan 28||Jan 29||Jan 30||Jan 31||Feb 1|
|Ounces of sap||0||0||0||96||0||0||0|
Weather conditions only held up for 1 collection day.
Week 3 Feb 2 – 8
At first glance, this weather looked P-E-R-F-E-C-T for collecting maple sap–and it was certainly pretty good.
As an important side note, too, since the weather looked like it was going to be perfect, I drilled a second hole in my very large maple tree. My thought process here is that it should help extend my season by about 2 weeks and double my production over many of the weeks in the middle.
Here is what that all translated into, in terms of sap collecting:
|Feb 2||Feb 3||Feb 4||Feb 5||Feb 6||Feb 7||Feb 8|
|Ounces of sap||0||384||352||80||64||80||64|
The only day that was not productive was Saturday.
It looked like a good day, on paper, but it came off the bitterly-cold polar vortex temperatures and there just weren’t enough warm hours to thaw the ice.
But still, over 1000 ounces of sap in the week. This was an amazing amount of sap and certainly was a week I would not have wanted to miss.
Week 4 Saturday, Feb 9-15
The weather for this week looked too cold for the first half, but excellent for the second half.
Check out the sap collection for this week:
|Feb 9||Feb 10||Feb 11||Feb 12||Feb 13||Feb 14||Feb 15|
|Ounces of sap||0||0||64||0||363||264||250.8|
Saturday, Feb 9, Sunday, Feb 10 and Tuesday, Feb 12, turned out to be too cold to collect any appreciable sap.
While the temperature technically got above freezing each day, it didn’t stay above freezing long enough for the sap to run appreciably
Monday was an okay day, not great. I recorded 64 ounces of sap, but in truth, that is a bit low, because much of the sap was frozen solid when I collected it.
Since the pure water freezes first, it actually concentrates the sugar and other dissolved nutrients in the remaining sap. So while the volume was low (~64 ounces), the sugar content was higher than usual.
Wednesday, Thursday and Friday turned out to be very good days, with approximately 2- 3 gallons collected each night.
Week 5 Saturday, Feb 16 -22
Week 5 looked like a bumper week, from the beginning. The forecast had lots of nights below freezing and days in or very close to the 40s. This is how it turned out:
|Feb 16||Feb 17||Feb 18||Feb 19||Feb 20||Feb 21||Feb 22|
|Ounces of sap||0||80||308||99||0||363||250.8|
The pattern was still sporadic, with 3 really good days and two small days. Surprisingly, there wasn’t much to show for Saturday.
Not exactly sure why. It technically wasn’t a zero, but there was so little in the buckets that I didn’t bother to collect it, I just waited until Sunday and collected that small amount then.
Turned out that Monday and Thursday were the big days I had hoped (but not the biggest of the year), and Friday wasn’t too shabby either.
Wednesday started frozen and ended frozen, so I didn’t even bother.
All in all, however, Week 5 was the highest producing week so far, bringing in approximately 1100 ounces, or just about 8.33 gallons of sap for the week, and nearly 26 gallons for the season.
Week 6: February 23- Mar 1
Here is the weather looked like for week 6:
On the surface, the ranges look relatively suited to collecting sap, but the reality of the hourly weather, the temperature changes just didn’t hit the right pattern for the sap pressure to build up and release.
Here is what the week produced:
|Feb 23||Feb 24||Feb 25||Feb 26||Feb 27||Feb 28||Mar 1|
|Ounces of sap||0||128||128|
Week 7: March 2-8
Week 7 here looked pretty bad. A cold snap flattened out my weather and kept it below or too close to freezing for most of the week. The vast majority of sap was harvested on Sunday, March 2nd, which was the largest harvest of the year. Monday was decent, but then I got skunked for 4 days in a row after that.
|Mar 2||Mar 3||Mar 4||Mar 5||Mar 6||Mar 7||Mar 8|
|Ounces of sap||416||160||96|
Friday wasn’t a perfect day, but it did yield some sap.
Week 8: March 9 – 15
Watching the weather here is fascinating. It might sound repetitive at this point, but what is needed to produce large amounts of sap is a strong temperature differential dipping below freezing (by enough to form ice crystals in the tree–probably like the 20s) and then thawing out into the 40s. Last week, it was cold and didn’t get warm enough. This week’s weather produced a few days that seemed to be a textbook day in terms of temperature differential and a few that were actually too warm…UGH.
|Mar 9||Mar 10||Mar 11||Mar 12||Mar 13||Mar 14||Mar 15|
|Ounces of sap||0||140.8||192||80||140.8|
and the actual sap yield appeared to be declining.
Week 9: March 16-22
At the start of this week, the weather (on paper) looked picture-perfect, but it turned out NOT to be that way. The temperature stayed above freezing for most of the week.
Monday looked like it was going to be textbook perfect, but it yielded no sap.
Take a look:
I checked Tuesday, and Wednesday, Thursday, Saturday. The lines were dry. No sap flowing. My season is over.
No sap flowed at all.
Taps were dry, on textbook perfect days (temperature wise).
|Mar 16||Mar 17||Mar 18||Mar 19||Mar 20||Mar 21||Mar 22|
|Ounces of sap||0||0||0||0||0||0||0|
Buds were on the branches. Not sure if this had something to do with it, too:
The season is over, for me. I pulled the taps on Sunday, March 23.
Week 10: March 23 -29
Here was the weather for the following week:
Monday-Wednesday might have been sap-producing days, based on the temperature differentials from morning until afternoon if the holes hadn’t dried up.
The rest of the week was definitely too warm.
Week 11: March 30- Apr 6
Here was the weather for the following week:
Even though it says the temperature is going down to 27 degrees on Monday, the hourly forecast showed it just barely creeping down below freezing. On paper, this week would have produced ZERO sap, unless Sunday-Monday truly did dip below freezing.
I tapped my trees on January 19 and then added 1 more tap to the largest tree on February 2. During the entire season, it is estimated that my two trees produced nearly 38 gallons of sap!!
You can see that my taps yield sap for a total of 8 weeks (maybe it was ~6 weeks, recognizing that I started a second tap 2-weeks in).
So, when was the best time to tap a silver maple tree in Southeastern Pennsylvania in 2019?
From the looks of it, February 2nd, 2019. My season ran from the week of 1/19 to 3/9, but those first two weeks of the season were cold and yielded a little, whereas the March weeks had much better temperatures.
Looking back in hindsight, I wonder if one of the two taps in the larger tree had started to dry up in those first two weeks of March (after 6 weeks of producing), which is why the yields went down, even though the weather was decent.
So, all-in-all, I feel pretty good about when I started the season. 1/19 was a bit early, but it was pretty close. If I had a crystal ball and could start over again, starting 2 weeks later (2/2) may have extended the harvest a bit–but I’m not sure. Since I’d only be risking ~200 ounces of sap from those first 2 weeks, it’s worth the risk.
I certainly didn’t miss the season too badly, however, because the season was certainly over, temperature wise, by mid-week 3/23.
Deciding when the best time to tap a maple tree is really just a guess. It’s highly dependent on the weather. In 2019, I tapped my trees on 1/19 and got 38 gallons of sap! I think I could have improved that harvest a bit (maybe by another ~2-4 gallons MAX–and that’s being optimistic) if i started 2 weeks later. I have no way of knowing, it’s just a guess. If I had to pick a single, best date to start, I would say it was probably February 2nd, 2019, this year.
I hope that helps. Did you tap maple trees this year? If so, where do you live and when did you start? Any advice you would share here?