Garlic cloves should be planted in March and harvested when the the leaves turn yellow in July /August. One would assume that since you planted in October ???
the yellowing of the leaves indicate that the Garlic is ready for harvesting , pull one and see ;)
You're a bit off beam there Skypilot, your lucky if you get a decent crop of garlic from a March planting. They need cold weather and a long time in the ground
Yellowing of the leaves, in my experience is not unknown at this time of year
Phil