The mystery of when to tap

[buckeye gold]

I have been at this game for a little over 10 years and have watched the debate on when to tap repeat it's self every year at this time. Some stick to tradition and some fall prey to early itches and some just don't know what to do. In my professional career as a fish hatchery Manager we dealt with these same conditions and trends. Timing a fish spawn was extremely critical in our production success. We charted water and air temperatures for over 50 years and had a pretty good handle on the trends and extremes. Since fish are triggered by temperatures we watched water temps. closely. The key here is the word triggered. Temp. was not the sole controller, but a final trigger. every year I would have someone panic over a warm spell. The thing that set the stage and really made the most difference was Photo Period (length of days). The temperature was a key, but it was not the door. What we would see is that abnormally warm or cold would not set the main spawn into action with any variance beyond about 10 days. when i reviewed production records I would see that peak spawn almost without exception would happen in a 7 day period annually. Now we could always find the outliers and there were the years we had early seasons, but the trends is what we followed. I can see a lot of similarity in sap flows. If we tried we could always capture some early spawning fish, but it was a waste of time, gear and man hours to panic and jump the gun early. I did see trends moving to earlier dates, but by only a few days. I see the same thing in maple sap. Keep good records and be ready 10 days before your historic dates and then watch trends. Your prime production will almost always fall within the same 2 week period. when you start should never exceed 3 weeks prior to your historic best production dates. I use 3 weeks because of a typical 6 week season and that puts your peak production mid season even if you are in error and it turns cold after a warm spell. If it turns out to be early and warm you still hit your peak. I looked at all my tap dates and my start has only varied by more than 2 weeks once. I am talking about my main woods, not the fall or early taps that I use as a bonus. When we were going after eggs we were always ready two weeks early and would go when water temperatures were right after that. So my best policy is to be ready to tap 2 weeks early and then tap when the trends say so.

I plotted the weather from November thru January and saw trends that showed high swings then settled to periods of normal with a cold period followed by extreme highs followed by a long period of normal. We are now going into a period of average temps if my plotting is right. I think the next two weeks will be pretty close to normal. Now this trend gave us abnormally cold later than usual, so My taps are late. I would guess that for those north of me the same will hold true and your tapping date will most likely be a few days later than the norm, but I look for that extreme warm up to hit about March for a few days. So depending on your system this may wreck your season.

Hey come Late March you all can call B.S. and tell me how wrong I am.

[bigschuss]

We really could is an algorithm that tells us when the best time to tap is. ;)

Just being funny....yes, I agree. With few exceptions Mother Nature tends to land right on time each year. I keep track of my first robin sighting of the spring for example...95% of the time I see it within the same 5 or 6 day calendar window. The whitetail deer rut I can pinpoint to roughly the same 6 or 7 day window in November. The first woodcock flying in the back field will show up the 2nd week of April, and the first cicada I hear each summer will be the last week of July. And I tap, on average, the first week of March. Two years ago we had a very mild January and February, and we tapped unusually early the first week of Feb. But, as you said, I was prepared for it and enjoyed a nice early season for a change. So really, I don't think it is a big mystery, but I think that's your point.

[DrTimPerkins]

The "start" of the maple sap flow season has shifted by about 10-14 days (earlier) since the 1970s (and probably by nearly a month since the late-1800s). However, people should still watch the forecast, and also look at the long-term average weather to determine the best window of when to tap. Tapping early is fine IF you are using good vacuum and are practicing very good spout/dropline sanitation as you'll have a 10-12+ week window for good sap flows. If you're using buckets or gravity tubing, or are not practicing good spout/dropline sanitation, then your window for good sap flows will be FAR smaller, on the order of a 4-6 weeks before tapholes dry out. Tapping early for many of the larger producers with tens of thousands of taps is a matter of getting it done in time. They will make syrup during the thaws, but may not be fully tapped in. If you've got 10 buckets...that's a couple of hours, so there isn't a strong need to tap early.

The problem is that the "itch" is very strong in some people.

The most common outcomes are:
1. Tap early, get some sap, but flows slow down or stop during what is normally the best part of the season (negative outcome of tapping early).
2. Tap early, get some sap, then it gets hot and the season stops prematurely (positive outcome of tapping early).
3. Tap at the normal time, have a good regular season (positive outcome).
4. Tap at the normal time, it gets hot and season stops early (negative outcome).
5. Tap late, season ends (negative outcome).

In many ways it's a crap shoot, but you want to maximize your chances of success. Usually that comes by tapping near the "normal" time for your area and method of collection (gravity vs vacuum) or by tapping early if you are on vacuum and using good sanitation practices. But occasionally Mother Nature will screw with us...but there's really no way to know ahead of time when that'll happen.

In terms of reaming out tapholes and other approaches to rejuvenating sap flow after tapholes dry out....it's really hit or miss. Sometimes it works, sometimes it doesn't. The strategy of putting in a second taphole, even if very close to the first, will very frequently mean that you've made double or more the wound, which is unlikely to be sustainable in the long-run (unless the tree is large enough to be a two-tapper and you only put in one taphole to start with). We are in the process of doing research on these approaches, but we don't yet have enough years of data to make good recommendations.

[buckeye gold]

I figured we'd hear from Dr. Tim and I appreciate your input. So we have a 3-2 chance of a negative outcome from early tapping :mrgreen:

[O3C]

I'll throw my 2 cents in on this, I finished tapping today, have 300 taps in and am expecting an early spring not because of the goofy groundhog ! Penn State has a cable weather program called Weather World that airs weekdays and is 15 minutes long probably online also. It is pretty good about explaining the weather and weather patterns. They will do long range forecasts but always preface them with the idea that they shouldn't be doing long range forecasts. This has been the wettest year on record here in Pa. They went back and looked at the 6 wettest years on record and they were all followed by an earlier than normal spring. They did not predict an early spring. This is only my 5th year tapping maple trees so I have a lot to learn about when to tap, trees budding, and sap runs, but spring is pretty important around here. We have milked cows forever but the last 14 years we have had a spring seasonal herd. The earliest we have been able to stop feeding hay and have the cows on full grass has been March 17 and the latest we have gone is May 7th. I realize there is no correlation between sap runs and grass growth but there can be quite a variation in dates. So I am tapped and rooting for an early spring. Sure wish the maple house and especially the evaporator were together. Guess what I'm doing this weekend ! Ron