By Evan Elford, OMAFRA New Crop Development Specialist & Alexandria Verkuyl, OMAFRA Summer Horticultural Research Assistant

As hop harvest approaches each year, questions arise about harvest timelines for specific cultivars grown in Ontario. Since hops are a re-emerging crop in the province, only preliminary information has been collected from replicated trials.  Here are a few guidelines and suggestions for planning your hop harvesting schedule this year.

Moisture test:
Target 20% dry matter in hop cones.  Moisture levels for some cultivars may be optimal at a slightly higher or lower dry matter percentage, but most fall within 20 ±  2% range.  By targeting initial harvest at 20% dry matter, larger fields taking more time to harvest or cultivars being harvested over multiple days will hopefully be completed within an acceptable moisture range.

• A useful online tool for calculating harvest moisture in hops can be found on the University of Vermont website at the following link: http://www.uvm.edu/extension/images/engineering/hopscalc.html

Historical records:
Historical harvest records can help to schedule cultivar-specific harvest windows in your growing area but should always be confirmed with moisture tests. Table 1 depicts harvest timelines over two years for 10 different cultivars grown in a randomized and replicated trial at the Simcoe Research Station, Norfolk County, Ontario.  This table can be used as a guideline to better understand when specific hop cultivars may be maturing in your part of the province.  Keeping your own harvest records will help fine tune harvest dates in your particular growing region. Table 2 outlines the same cultivars with harvest dry matter, yield in kg/ha after drying and resulting alpha and beta acid ranges.

Table 1: Harvest date ranges for 10 hop cultivars grown in a randomized, replicated field trial completed by the University of Guelph located at the Simcoe Research Station, Norfolk County, Ontario.  Data is compiled from the 2014 and 2015 growing season from 2^nd year and 3^rd year hop plants respectively (McDonald et al., 2016).

Table 2: Harvest parameters and resulting resin results for 10 hop cultivars grown in a randomized, replicated field trial completed by the University of Guelph located at the Simcoe Research Station, Norfolk County, Ontario.  Data is compiled from the 2014 and 2015 growing season from 2^nd year and 3^rd year hop plants respectively (McDonald et al., 2016).

Hop Rub:
Begin to familiarize yourself with cultivar-specific characteristics.  Breaking apart or rolling a few hop cones to observe the aroma, lupulin colour and feel of the bracts can help growers know if the hops are ready for harvest or if they are too early or too late.  Most cultivars will exhibit the aroma of fresh cut grass and pale yellow-white lupulin if too early, while hops that are past maturity typically exhibit a rancid smell or aroma similar to alliums (onion and garlic) and lupulin will turn a dark yellow-orange colour.

References:
McDonald, M.R., Bakker, C., Elford, E.M.A. 2016. Hops: A potential niche crop for Ontario, 2013-2015 cultivar evaluation. Final Report for the New Directions Research Program.  Available: http://www.omafra.gov.on.ca/english/research/new_directions/projects/ndprojectindex.html

PDF Version of this article available here: Hop Harvest Timelines in Ontario

PDF of Table 1:Table of harvest date ranges for 10 hop cultivars grown in Ontario field trials 2013-2015

PDF of Table 2:Table of harvest data for 10 hop cultivars grown in Ontario field trials 2013-2015