Actually ice is used to protect plants in the warmer regions that get cold snaps. Growers in Florida will cover their crops with ice. Im not entirely sure of the science behind it but it has to do with the fact that the ice will actually insulate the plants because it is only 32 degrees versus how ever colder than 32 the air can get.

My onions have been inground here in tulsa for about a month and out of 100 plants we only lost about 5 to all the really cold snaps we had.

Im sure the more experienced gardeners can explain it better and have more advice.

Mike

Mine have gone though ice and snow and are ok. The crazy weather may cause some bolting, but I would not expect anything worse.

Larry

Thanks.....

Ice and snow can be protective, but damage can occur anyway. I like snow as an insulator better than ice. I've had onions survive just fine when snowed upon, but have lost some or all of them after they were encased in ice. I think a lot depends on their size, how hardened off they are already to lots of cold weather, etc.

Also, it depends on how cold it gets and how long it stays that cold. Temperatures in the lower 30s and upper 20s usually won't hurt onions or garlic, though sometimes the leaves suffer some damage . If the temperatures go below about 26 degrees, you might have trouble with the onions more so than with the garlic.

Most cool-season plants tolerate frost to some degree and most tolerate light freezes, but most of them do not tolerate a hard freeze. They might die completely or they might die back to the ground and then regrow. It kinda depends on how hard the freeze is and how long it lasts.

Having garlic and onions mulched helps protect the in-ground portions, even if the above-ground portions freeze.

My onions survived a very hard freeze, with overnight lows down to 19 degrees. We were below freezing for 9 hours that night a few weeks ago. The onions were fine under a floating row cover. The garlic, also under a floating row cover, suffered a lot of leaf damage but the leaves didn't freeze back completely---just the tips of the leaves froze, and the garlic has put out some more leaves since then so obviously the bulbs weren't injured.

Sometimes when they spray water on citrus plants to protect them from freezing, it works well but if the temps are too low for too long, those fruit do not maintain the quality needed to sell as fresh citrus, for example. However, they can quickly harvest them ASAP and rush them to the factory to extract the juice for frozen juice concentrate if the citrus fruits are close to being ripe. That helps the growers avoid a total crop loss. It is better to get something from the crop as opposed to losing it all.

I have my onions and garlic mulched and will throw a row cover over them tonight even though our forecast only shows 34 degrees for a low. This spring, and I mean in very recent weeks, our early morning low has dropped as much as 9 degrees lower than forecast so I look at "34" in the forecast and think to myself "hmmmm....25 to 28 degrees then".

Dawn