Garlic harvesting time

Friday, July 30, 2021

Hard neck garlic harvest in Nova Scotia typically happens the first week of August, although with how hot this summer has been (Table 1), some varieties are a bit ahead of schedule.

Table 1. Degree day accumulations as of July 26, 2021.  All data are taken from the Kentville weather station, based on a start date of March 1, and calculated using the single sine method.

Fig. 1. This garlic from mid-July, isn't quite ready to
harvest. Note how the wrapper leaves aren't yet snug
around the cloves.
I have blogged about garlic harvest timing in the past, and if you haven't come across it before, I strongly recommend giving it a read!  The number of green leaves left is a good tell, but if your garlic is super healthy, or super sick, it might not be the best barometer (Fig. 1).  You can find the blog post by typing "garlic" into the search bar on the right of the NS Vegetable Blog, or for direct access, click here.  

By mid-August my car usually smells of garlic from all the samples of unhappy garlic I've collected from growers.  This is often the result of poor post-harvest management.  August in Nova Scotia, when growers are trying to cure their garlic, is often a muggy month, providing poor drying conditions. 

Fig. 2. Relative humidity and temperature.
You NEED good air circulation and ideally low relative humidity (less than 70%) in your curing space otherwise you run the risk of disease running rampant.  If your garlic is taking more than three weeks to cure, it is likely your relative humidity is too high.  There are cheap sensors available from Canadian Tire or Amazon to measure relative humidity and temperature.  If you are serious about growing garlic, I strongly recommend you get one.  Some of the nicer sensors even upload it to a web portal (Fig. 2) so you can check on it from the comfort of the couch. Move the sensor around your drying space to see if you can find any "dead" space with low air movement and higher relative humidity.  Those are the areas where disease is most likely to rear its ugly head.  It is best to try and move some fans to around to get rid of this dead space.

Fig. 3. Unhappy garlic - Penicillium (blue) and
Rhizopus stolonifer (white and black fungus). 

Did you know you could submit samples to 
Perennia's Plant Health Lab?  This service
is often free for registered farms.  Reach out to
 Rosalie Gillis-Madden, 
if you have a vegetable
sample you want to submit to the Plant Health Lab.

It shouldn't need to be said that diseased garlic should not be used for seed.  Advanced growers with smaller plantings sometimes earmark particularly healthy plants in the field before harvest as candidates for seed stock.    To read more about garlic storage, post-harvest diseases, and planting stock considerations, check out Perennia's factsheet.

Fig. 4. Garlic storage, post-harvest
diseases, and planting stock considerations
fact sheet.