First of all I would like to thank this forum for its existence. Here is my current issue. We recently had a freeze about a month ago and I purchased these supposedly freeze protection covers for my young citrus trees (lemon and grapefruit). The temperatures dropped to 28 degrees and the covers failed. All the leaves were brown and the branches looked like they were sucked dried. I did a bark test on both and the entire tree was brown but the lower trunk was green. Unfortunately, I think that is where the graft is. My question is, If only the graft survived, I’m not going to get what the trees are supposed to be right? I attached a picture of the trunk and circled the part that is still alive. I believe it’s below the graft.
Welcome to the forum. So sorry that your tree got damaged. I’m surprised that it froze back that far at 28F. What I’d do is nothing until it starts growing. If all growth is from below the graft then you’ll need to get another tree or regraft this one.
You probably had sustained freezing temps on a few nights. More than the lows (of course, up to a threshold), citrus are affected by how long the freeze lasts. I’m not an expert on this, but I hear covering the tree has its challenges. If it doesn’t allow the morning sun to heat up the tree quickly, the cold accumulates and can be harmful to the tree.
I agree with @fruitnut to wait. Citrus are much easier to graft on the rootstock than the interstem, so if the rootstock sprouts, you can try that.
Like others have said, you will need to wait to see if you get new growth from above or below the graft. Also, I would remove the mulch a few inches away from the trunk.
Thank you for all your replies. I will wait and see what grows back. I already moved the mulch. I only had it that close to protect it from the frost for that one night. I’ve only had these trees for 1 year which I purchased from Home Depot last year. I will update this thread with the results.
Did the frost fabric drape to the ground or you tied it to trunk?
It came with a drawstring at the bottom to secure it to the trunk so it wouldn’t fly off.
Here is a little basic video that LSU put out recently on covering citrus . Not enough protection for temps in the teens, but helpful for short term cold spells.
Thank you so much. I will definitely check it out. We rarely get temps under 30 in my area but for the last 2 years they’ve dropped to 28 and 27. Last year I lost my 4 year old orange tree but that was a constant 28 degrees for several days. This time it was only for 6 hours and it was enough to damage them severely.
In my experience citrus is not very cold hardy. Most citrus trees are recommended for zone 9 and above.
I am in zone 9a.
Next time try the set up this way
Oh, man. That’s a bummer. I think @GeorgiaGent has the right idea in that you need the ground heat to be trapped under there with the tree. Those cinched up covers will protect from drying winds more than the cold. Basically, it comes down to the fact that your trees don’t have very much thermal mass compared to the ground, so even with some insulation, it doesn’t take long for it to equalize with the air temps.
I like that idea with the bulb but my trees are at a ranch that does not have any electricity. I was thinking maybe making a square frame around them and then wrap it in clear plastic versus the fabric cloth and cover the top with a blanket. Someone also mentioned keeping some bricks at the base to absorb heat as well.
Update: So my grapefruit tree is showing life but only below the graft. Correct me if I’m wrong but that means this tree could be any kind of citrus and may not be a grapefruit? The arrow is pointing where the graft starts which is completely dried out.
Another question. Does this lemon tree trunk look like it’s grafted? I bought it at Home Depot last year but it froze. I’m thinking of pulling out the root stock and replace them.
What part of northern California do you live in?
28F shouldn’t kill citrus tree even if several days duration except for lime tree.
Rootstock won’t be grapefruit.
Meyer lemon likely a rooted cutting.
I’m in South Texas and these trees did in fact freeze that one night. I did the bark scratch test and they both failed. I also have a nectarine and plum tree that haven’t woken up but the bark and branches are alive. I did the scratch test on them and the bark is green. Thanks for the information as I will replace both of them.
Update: My Plum and Nectarine trees are doing great. My lemon tree was completely dead so replaced it and i removed the grapefruit that only had root stock growth. I did put it into a pot to see what grows from it. Just curious. I did replace it with an orange tree. Thank you for all your responses.