Upcoming week

Temperatures are forecast to remain below freezing in many areas of the province early in the week.   Predicted weather for late in the week suggests that sap flows may occur in southwestern and south central regions of the province by the end of the week and into the weekend.  Reports from producers tell that many maple producers will be tapping maple trees during this coming week.

Experienced maple producers say that tap holes will only run on average for 5 or 6 weeks.  The strategy of tapping a maple bush is to tap maple trees to time the short lifespan of tap holes to coincide with ideal temperature conditions for the best collection of sap.  Drilling tap holes too early, that is, drilling well before the best sap flow conditions can reduce harvest of the best sap flows.  The risk of tapping too early can cause tap holes drying out before the sap run season has finished.

Sap flows will begin to occur after several days of above freezing daytime temperatures to allow maple trees and tree roots to thaw out.  For sap flow events, ideally we need nighttime temperatures of – 5 ˚C and warmer daytime temperatures of at least + 5 ˚C to occur several days consecutively.  Watch for these forecast conditions to predict sap flow events.

Tapping guidelines

With the possibility of sap flow by the end of this week some producers may decide to begin tapping sugar bushes in early areas of the province.  For best tapping conditions, do not drill tap holes into frozen trees as this can damage the tree when spouts are tapped into the freshly drilled holes.  Wait until temperatures are above -5 ˚C and have been above – 5 ˚C for a sufficient amount of time to allow the trees to thaw.

Efficient sap collection requires care is taken to drill the tap holes properly.  Use sharp drill bits that are the appropriate diameter for the spouts you are using.  The drill bits should be clean and sanitized several times during the day where possible, so it is handy for workers who are tapping to carry extra drill bits to change during the tapping work as necessary.  Tap holes should be as round as possible and not oval in shape due to improper drill habits.  A cleanly cut round hole will allow for best sap collection where tubing and vacuum systems are being used to collect sap.

Proper tapping guidelines should be followed to help ensure that the health of the sugar bush is maintained or improved.  Two tapping guidelines are prescribed, one for healthy trees and one for trees that are under stress.

Healthy trees:  For healthy trees, trees that are less than 10 inches in diameter at chest height should not be tapped.  Trees 10 to 14 inches in diameter can receive one tap.  Trees 15 to 19 inches in diameter  - 2 taps, and trees greater than 20 inches in diameter - 3 taps.  

Stressed trees:  For trees that are under stress and less than 12 inches in diameter at chest height - no taps.  Trees 12 to18 inches in diameter - 1 tap.  Trees greater than 18 inches in diameter - 2 taps.  Large maple trees that are under stress should receive no more than 2 taps per tree.

Proper syrup density

Maple syrup can only be legally offered for sale if it has reached a density of at least 66 ˚Brix.  To obtain this minimum density, syrup should be boiled until it reaches a temperature of 4 ˚C (7.1 ˚F) above the boiling point of water.  Therefore, minimum density maple syrup will boil continuously at 104 ˚C.  A final syrup density between 66.5 and 67.5 ˚Brix has a more pronounced maple flavour and better texture, ideal for quality maple syrup and returning customers.

The only way to ensure that the legal minimum sugar density is reached is to know that thermometers, refractometers and hydrometers are calibrated properly with each batch of processed sap and syrup run.  Remember that the boiling point of water can vary with changing barometric pressure and can change significantly during the course of each day therefore thermometers need to be calibrated with each batch of syrup processed.

Consider planting windbreaks around exposed woodlots

Maple woodlots that are sheltered by conifer windbreaks around the perimeter of the woodlot may experience better sap flows.  Morning temperatures can warm up quicker in a woodlot that has windbreak protection, which can thaw frozen sap lines quicker and encourage sap to flow sooner from thawing maple trees.  During the approaching sap collection season, make a note of each area that could benefit from wind protection to encourage better sap flow and protect the woodlot.  Now is a good time to place orders for trees from private nurseries if tree planting is needed for the coming spring.   

Woodlot Meetings

Maple producers can take advantage of several upcoming Woodlot Owner Workshops to learn leading-edge technology of woodlot management.   The Grey/Bruce Woodlot conference will be held March 28 at the Elmwood Community Centre.  The Ontario Woodlot Owners Association annual conference is March 28 in Acton.  Contact MNR Stewardship Coordinators for meeting details.

This maple production agriphone report was prepared by Todd Leuty, Agroforestry Specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs.