August 7, 2012

Normally we think of garlic harvest time being somewhere around mid to late July, but very little about this year is normal! Garlic is maturing considerably ahead of schedule, with some growers on light soil or plastic already beginning to pull some varieties now. In some cases the plants are not dying back on schedule with the bulb, so don't just use that as an indicator. If you have had any foliar disease or thrips feeding, the foliage may be ahead of the bulbs. If your garlic has been kept very healthy and well watered the leaves may actually be behind. I have been pulling a fair amount of garlic in the last few days which only has a couple of leaves dead but which will probably be ready to harvest very early next week.

If leaves aren't the best indicator of maturity, how else can you tell? The best indicator is how the cloves are filling the wrapper leaves. Take a couple of average looking plants from each variety, and cut them in half perpendicular to the stem so that you are cutting through all of the cloves. Each clove should be tight in its wrapper leaves. If there is any give when you squeeze the bulb, or the wrapper leaves seem a little loose around the cloves the garlic will continue to expand for a little while longer (figure 1). A few of the outer wrapper leaves will probably be breaking down. That is normal.

You can also look at the shape of each clove. Cloves start out being more or less round, and expand to more of a wedge shape (figure 1). As garlic reaches full maturity, the cloves will pull very slightly away from the scape on hardneck varieties.

If you let the garlic stay in the ground too long, too many wrapper leaves will decay and the cloves will continue to expand until the garlic actually splits open. At this point the garlic becomes virtually unmarketable. Make sure that you check your garlic every few days, especially as we move into another warm stretch of weather.

As you are harvesting, keep in mind that you want to reduce the amount of water that you bring into your drying area and you want to avoid scalding your garlic during harvest. If you can harvest early in the morning (before 11 or so, depending on how hot the day is) on a dry day, then clean in the shade during the afternoon, you should have the best results possible. Allowing garlic to sit out in the field exposed to the sun can result in sun scalding, which will cause affected cloves to break down. If you have to harvest in wet weather try to remove as much mud as possible and to get any foliage you leave on the plant as dry as possible before moving it into the curing area. The higher the relative humidity is in your curing area, the slower the garlic will dry down. The slower the garlic dries, the more potential there is for disease. Dry garlic means lower relative humidity right from the start!