Here's what the plants in the ground look like. They are in a raised bed. Southern California.

irregular watering, too much water, or leaving them in the ground too long can cause it. should periodically harvest a bulb to check when they're ready, you can't really rely too much on the foliage as an indicator. also, avoid having too much mulch/straw around the bulbs.

Thanks for the comments Stevie. I had the same problem last year. And the straw mulch is new for these two years. Maybe I will do less straw or none next year. The beds have drip irrigation which is on a regular schedule but off when it rains. We had 4 inches the last few days,

For years, I've been wanting to know what causes this garlic phenomenon. It has happened to my garlic since planting my hardnecks from Arkansas (7b) to Central Texas (8b). I haven't got any luck finding the answer here in this forum. All I know is:

#1. No, this was not left over/forgotten bulb from last years harvest that was left in the ground.

#2 This is not an over matured garlic that has sprouted because it was left in the ground for toooo long.

#3 Not from too much watering or fertilizer either.

Last year, from the FB group I'm following, somebody told me this phenomenon is called garlic brooming or garlic witch's broom or simply brooming. In my case, this is caused by planting garlic NOT suitable for my growing Zone. No amount of vernalization helped either. I tried it 3 different seasons, vernalized hardnecks for 2 weeks, 4 weeks and 8 weeks. They still broomed. But they are still edible though. The only thing you'll notice is the clove wrappers will be thicker than normal.

I wonder why you are watering garlic.

ibarok. Thanks for giving me the "garlic witches brooming" name. I searched that term and came up with some possibilities. One is too much fertilizer, especially nitrogen. The other is fluctuating temperatures. I am growing California Early because I think it will be most suitable to my climate. We don't have much of a winter and it can go from hot to cold to hot to cold throughout the fall/winter. It did occur to me that this looks like garlic that has gone through a second season.

I think I will still get quite a bit of usable garlic. The first one I harvested was the equivalent of 3 heads, 1 large and 2 small. Another thread mentioned dehydrating the garlic if it doesn't look like it will store. I will probably try that this year.

Jim Mat, we can go for months without any rain. Very little would grow without irrigation. This year, we did not have any rain in January or February and then got some in March and April.

I grow garlic without watering after the first rain. SF Bay Area. Doesn’t matter how much it rains or doesn’t. Maybe your garlic is different from garlic grown in Nor CA

wcthomas, thanks for sharing your expertise and experience. I amend my beds before planting and don't add much fertilizer. I might try some bloodmeal next year., I harvested this week. Here's a sample of what my crop looks like:

I think my overall yield is good. Many of the cloves are nice sized. My guess is that weather plays a big factor. I think the garlic looks like it went through 2 seasons, forming heads with cloves, then splitting and starting new heads.

I am in Nor Ca, Inlet my garlic flower, then bend over the stalks, let them dry and harvest around July.

You and I must be growing different garlic.

Here is a photo of what I call "Witch-Brooming". I get this on about 10-20% of my garlic plants. The plant in the photo had a scape, but sometimes the plants with witch-brooming have a smaller scape, or rarely none at all. This year I'll look more closely to see if the witch-brooming affects the quality of the bulbs.

Which percentage

This year I grew 18 of the CA Early garlic and 100% of them are split. I have 9 CA Late garlic and none of them appear to be split. They are in the same raised bed with same watering and fertilization.

Hard to tell from the photos above, but if the garlic was harvested late (after maturity) that could have been the cause of splitting. As a rule, the skin of the bulb corresponds to the number of fully green leaves at the time of harvest. If all of the leaves were dead or browning when dug, the skin may have rotted away. There are good garlic harvest tips (and a lot of garlic variety info) in the link below:

Heirloom Garlic Archive

The Early CA garlic did "appear" to be late but was actually early. Planted in October 2021 and already splitting in March 2022 before the cloves were full sized. I also had Late CA garlic which I harvested today (May). It is fine, no splitting. Same bed, same ferts, same watering schedule. My conclusion is that I will not try the Early CA again and will stick with Late CA or try other varieties. I may skip garlic next year and rotate crops in beds.

All my garlic did this. I have 24 Inchelium Red plants and they all broomed. Supposed to do well where I live. Will try a different variety next year.