In The Garden: Planting Onions & Garlic

Garlic and onions can be planted in either the Spring or in the Fall.  At our home, we like to plant garlic and onions in the fall and harvest the bulbs the following spring. Growing onions and garlic over the winter tends to produce larger bulbs because the plants have a longer time to develop good root systems.  There are also fewer pests to deal with during the winter months.

Most gardeners should plant onions in September or October.  Garlic is generally planted a bit later -- October or November.  A good rule of thumb is to plant garlic sets after your first major frost of the year.

Bulbs or Seeds?

Garlic is almost always grown from bulbs. Onions can be grown from either seeds or bulbs, but we plant bulbs because I find them so convenient. Onion and garlic bulbs (generally referred to as "sets") can be purchased from your local garden center, or from various mail order suppliers.  You'll find that onion and garlic sets sold at the garden center are less expensive, but you won't have much of a selection.  In fact, the onions sold at our local garden center are sold in bags that don't even list the variety, just "yellow onions" and "red onions." 

Planting

Plant onions and garlic in full sun and in loose, well drained soil. The drainage is particularly important since very wet soils will cause the bulbs to rot.

To plant garlic, first separate the bulb into individual cloves. Plant these six inches apart in all directions. Garlic should be planted two inches deep into the soil with the pointed end of the bulb facing the sky.

Plant onions six inches apart in all directions.  The pointed part of the bulb should be facing upward towards the sky and the tip of the bulb should be just poking out of the soil.

Onion Types

When selecting onion varieties, choose ones that are appropriate for your area.  Onions produce larger bulbs in response to the number of hours of sunlight they receive.  In the North, the amount of daily sunshine varies dramatically during the course of the year, with many hours of sunshine in the Summer and relatively few during Winter.  

In the deep South, day lengths are much more consistent during the course of the year and summer days are not as long as they are in the North.  So folks in the Southern U.S. should buy "short-day" varieties (bulbs start to form when there are 10-12 hours of sunshine) and folks in the Northern U.S. should buy "long-day" varieties (bulbs start to form when there are 14-16 hours of sunshine). 

Intermediate-day onions fall between these extremes (bulbs start to form at 12-14 hours of sunshine).  See the map below  to determine which type of onion is right for you or check out the  Gaisma web site which lists hours of sunshine by month for the U.S. and other countries.

Below are some onion varieties to consider, but do an Internet search for type of onions that will grow best in your geography (long, short and intermediate day):

• Borrettana Cipollini onion - a small (2 inch), flat, yellow, long-day onion that is a good storage.
• Red Wethersfield onion - a red, long-day onion that's shaped like a flattened globe.  It's an heirloom variety from Wethersfield, Connecticut.
• White Bermuda onion - a white short-day heirloom originally from Bermuda but now grow extensively in Texas.
• Candy - A large, intermediate-day hybrid onion.

Garlic

Garlic falls into two main types -- soft neck and hard neck varieties.  Soft neck varieties are characterized by bulbs with many cloves of unequal size.  This is the type of garlic you most frequently find in the supermarket because they are easier to harvest mechanically and also have a longer shelf life.

Hard neck varieties, on the other hand, have bulbs that are smaller, but these bulbs are comprised of more uniformly sized cloves. Hard neck varieties also have a broader range of flavor profiles.

That said, garlic can vary tremendously in flavor with some varieties producing mild cloves and others that are so hot they'll blow your head off. 

Here are a few worth considering:

• Purple Glazer Garlic - a mild tasting, easy to peel, hard neck variety.
• Music Garlic - a moderately hot, hard neck variety with high yields.
• Chesnok Red Garlic - a mild strength almost sweet, hard neck garlic that is good for cooking.
• Ontario Purple Trillium garlic - a very strong and very early maturing hard neck.
• Italian Loiacono - a mild soft neck variety that stores up to 9 months.

Photo by Lee Kindness

Harvesting

Garlic and Onions planted in the Fall should be ready for harvest in June or July.  Timing really depends on variety and your location.  The best way to tell when to harvest is to observe for your plants for clues that it is time to harvest.

Harvest onions when the leaves lose their color and fall over.  Once this occurs, leave the onions in the ground for another 10 days to allow the onions to reach full maturity.  If possible, harvest onions on a sunny day since the bulbs will contain less moisture and will store better.  After removing from the ground, cure in the sun for 1 day to kill the root system of the bulb.  This also improves the storage life of your onions.  Then store in a cool, dark and dry place.

Garlic is a little trickier.  Wait till most of the leaves die back and turn brown, but before all of the leaves have toppled over as with onions.  We recommend testing by harvesting a bulb or two and checking to see if they are mature.  The bulb should be the appropriate size for the variety you are growing and you should be able to feel the individual cloves under the outer skin of the bulb.  If so, harvest the garlic and then cure in a dry place for two to four weeks.  Longer for very large bulbs.  When storing garlic, we don't trim the leaves or the roots.  We believe this helps preserve them, but there are more opinions on the best way to cure garlic than there are stars in the sky.