My, but you are brave. Since garlic varieties act differently in various climates, your trial method is the only way to go. In addition I would not fertilize after early summer and stop watering a couple of weeks before harvest. Those two stressors might heat up your garlic a slight bit more.

Another consideration is clove size. Bigger cloves of the hotter types like some of the porcelains or Japanese, tend to start out hotter than many and each clove being larger also tends to pack more of whatever punch each naturally carries.

You will very likely find some variation from season to season that like planatus suggests can be intensified somewhat by stressing your plants a bit as they start to bulb out.

You will also get different "fire" rating between raw and cooked for most varieties. A number that are intense raw are much more mellow when cooked.

Thanks for the thoughts, Dutch and planatus. I guess that I am fairly well on track, then, as I only feed once in spring just as growth starts and do cut the water off about three weeks before harvest. Temperatures here are usually bouncing around 90ð about then so that will also add to the stress factor. I don't use nitrogen in the fall since we are looking for root growth, but every other year before planting I prep the soil with a heavy dose of compost and till it in. I guess that you are also indicating that these trials need to be continued for a few varying seasons to get an "average" heat response.

I grow a varietie called thai fire, its pretty hot.

Here is a link that might be helpfull: jubilee produce

dman86, I looked into Thai Fire and it looks promising heat-wise. May have to order some late this summer. The only turban that I have is Maiskij and this will be my first season to grow it so we'll see how it does first. So far it looks pretty good, 100% sprouted. Thanx.

I have grown many varieties and sometimes they are hotter than other years.

The hottest garlics I've tried thus far were Bogatyr and Ron's Single Center (a.k.a. Trueheart). Still got a lot left to try, I'm hoping for better garlic weather than I've had the past two seasons.

Wet weather during bulb formation will lessen the heat, so I concur with the recommendation to withhold water late in the season.