When to Plant:
Garlic should be planted September to mid-October. Even if you plant the first week of September and mulch (more to come), you may have green growth from the garlic beyond the mulch layer and need to add more mulch. Any exposure of the green tips to winter may damage your garlic.
What to Plant
One clove will give you one head of garlic.
You want a hardneck type as these perform well in Northern Illinois. You might try softneck varieties but know that they still tend to perform poorly even with layers of mulch. Much of that will depend on our winter. Avoid grocery store garlic. This is commonly a softneck variety.
Hardneck varieties that have been recommended are 'Spanish Roja', 'Carpathian', and 'Georgian Crystal'. Drew Groezinger, a grower in Jo Daviess County, recommended to me 'German Porcelain', 'Chrysalis Purple', and 'Red Chesnok'.
Visit a farmers market in your area and talk to the growers there. If you purchase a head of garlic from them, these cloves can be planted in your garden this fall. Home and garden stores may have garlic too.
How Much to Plant
A homeowner asked me the other day how much garlic does one family need and much of it depends on your cooking style. A hardneck variety could have between 5-10 cloves in a head. If you are cooking 3-4 times a week with a recipe using 1-2 cloves each time, you may find that you are using one head of garlic a week. In my family, this is pretty normal.
Where to Plant
Garlic needs a weed free area. Fertile soil is strongly encouraged. As you think about where you want to plant it, keep in mind that garlic has a long growing season. This space will not be available for crops until June/July of next year. I've not tried to grow garlic in containers although I imagine if you provide the garlic with the right growing media, proper drainage, and mulch, it may grow. This could be an experiment though.
How to Plant
Garlic should be planted twice the height of the clove with spacing 6-8 inches between.
You need to mulch. A good mulch layer of 6-8 inches is needed to provide insulation for the garlic as it develops. You may find that you need to keep laying this down in winter months. Straw, leaves, and other mixtures are your best bet. In November and December of 2016, we experienced warmer temperatures then usual, and many growers stated they had to add mulch for their garlic. It may be the case this season.
Your garlic will be ready next June and I'll be giving you a report in May as to how to harvest, store, and cure your garlic.
To reiterate: Plant Your Garlic This Fall.