bragarif, they should definitely be planted in fall. I've grown tonnes of alliums now, including several globemasters, and all were planted in October/November, it gives them time to develop a root system before the growth spurt in the spring. One note, after 2 years I had the bulbs multiply and had 9 new bulbs just from one original, so make sure to dig them up in a couple years to separate.

Thank you,wouldnt it be better to pull them out after the foliage has died. They may rot in July August the hot rainy season.

It just depends if the soil drains well, if you have a low organic content, high amount of sand, it's probably fine. I would just worry about the bulbs getting enough cold to bloom again the next year.

Most flowering bulbs are native to the northern middle east, like Iran, Turkey and Caucus Mountains.