The problem with applying more mulch now is that the plants will start drying down soon, and you don't want to invite problems with too-wet conditions. Besides, the root mass under the bulbs is really big, and the cloves have formed. Interference at this point might confuse the little darlings. Look for scapes to come on any day now.

Don't be surprised to find that your bulbs are noticeably deeper than you planted when you dig them up. To some extent, garlic can use its contractile roots to move to a comfortable depth, jellyfish style.

planatus, thanks! I guess I wouldn't be surprised if the garlics actually moved down as they grew. They are very firmly anchored in the ground and these are big tall plants. I will leave them be but make sure to plant deeper next year. We had a fairly mild winter but who knows what the weather will be like next year.

My experience shows that actually garlics tend to go deeper, no matter how shallow you plant them. I have always planted mine, such that the tip of the seed clove is barely covered. But when I harvest them, they are about 2" below the surface.

To follow up on the thread, I harvested all of my garlic this week. Both types music and chesnok red did very well, and it appears that they did pull themselves down quite a bit. When I planted, the top of the clove was 1/2 inch below the dirt. When I harvested, the top of the bulb was 1 inch below the dirt and it was actually difficult to get them out.

Perhaps this fits here. Back in the late 70s early 80s (south of Carbondale) I had a heck of a time with garlic 'heaving' -- that is pushing out of the ground between rain-freeze-thaw's.

Because (I thought) my soil was a bit heavy on the clay side I'd play with different planting depths down to 2" combined with different mulches.
(LL: if you're into pulling weeds mulch with last years grass hay.)

Anyway, half the garlic would heave especially after a period of heavy late Jan early Feb rains...with the sun came out/soil thawed I punch them back down. The several I missed grew up like drunken sailors..but they grew. About 2" deep with or without mulching worked best.

When I read ikea's question and the well considered responses...it's 30 years later and for the last 5 years out here on the Hood Canal west of Seattle not a hint of heaving.

A last thought. In a geology class back at Fresno State in the early 50s I chashed down a phenomena then known as ice rafting. I remember pictures of a mile long string of telephone poles (someplace in Nevada/eastern California) popped off and moved 20 or 30 feet in a straight row.

Were 'my' garlic cloves mini telephone poles being ice rafted like the picture in Life Magazine? Or wuz it them aliens from over at Togie Springs out on a hoot?

Garlic does not move down in the soil. The clove you plant, the new bulb grows below the existing clove. To prevent heaving, mulch with 4-6" straw during the winter. Frost heave can be a commom thing in some areas.
I plant my garlic 1 - 1 1/2" below the soil surface in a 8" raised bed to promote drainage in the zone of the bulb to reduce frost heave.