The winter vortex hit us last week with low of 14F and 4 days of sub freezing weather. Very un-citrus like weather. Trees are 5-7 years old on flying dragon, swingle, or citrange root stock. Banked above grafts with mulch. Time to prune the citrus. IMHO not a chance that any branches survived above my banking with mulch at 12-14F and 4 days of freeze here near Houston. Tree will grow back just as big one year from now with loss of one year fruit. Have most of the budwood I need. The municipal mulch actually felt warm in the bank. Used 1 yard of “hardwood” and two yards of pine bark for banking. Some say cut now and other wait. I say now just above the banking mulch. 5 trees had a second graft high and those are all lost, the disadvantage of grafting high is you can’t bank them for freeze protection. A friend cut his trees before banking!
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That is cold!
I was just down to Del Rio TX. It got down near their all time low of 10F. There were citrus trees up to 10 inch trunks that were pristine prior to the freeze, ie no damage or sprouts off the trunk. So they haven’t had a severe freeze for some time. Also saw what was probably rootstocks of citrus that were probably frozen back at one point and lost the scion. Those were a mess of small sprouts from near the ground. That’s what you’ll see this summer on everything unprotected.
Do you know of any citrus being grown with protection? A guy with a greenhouse supplier said that he knew of citrus being grown in basically hot houses with roll up sides but no heat, near Orange TX.
A big nursery for citrus trees is in Orange, Tx called Saxon Becnel and Sons. They have several large greenhouses that supplies citrus trees to many areas of Texas. Nice people but they use swingle rootstock. Not sure if they have trees heated but I know their trees survived. Went to local lumber yard and they had just received their trees and they were fine. Another lumberyard had trees that came in before the freeze and they looked really bad, probably dead. They had them under awning but did not bring them inside.
Its hard to believe with 14 degrees and freezing rain last week and I checked the soil temperature today and it reads 64 to 65 degrees. Time to plant corn and tomatoes next week.
What is the problem with using swingle rootstock?
Saxon Bechnel uses citrange which is trifoliate x orange. Swingle is trifoliate x grapefruit. They use citrange since it grows 5x as fast as trifoliate. Trifoliate is the heritage rootstock for citrus near Houston as the artic blasts do occur here every 25-30 years. 1962, 1983, 1989 and now 2021. Wasn’t here for 1962 but here for the others.
Both citrange and swingle have hybrid vigor and grow very fast. They are not a cold hardy as trifoliate or flying dragon trifoliate. Cold hardiness hasn’t been necessary since the last artic blast in 1989. I did buy a quart of swingle seeds around 10 years ago so I have a tree on it now.
It is still to be determined if any citrus on any rootstock survived this artic blast unprotected in Texas. Last week I knew enough to bank to above the graft with mulch to prevent loss of the graft.
BTW in the Texas citrus belt near Brownsville 500 miles south of Houston they use sour orange as rootstock due to high pH soil. Sour orange is the least cold hardy of root stocks.
Curious how your satsumas look as compared with the other citrus? Did any of them make it through the cold?
For a comparison, we had 8 degrees with 2.5 inches of ice followed by 6 inches of snow. The snow lasted 7 days before melting. The orange hybrid seedlings I grew from the tree in Birmingham appear to be unharmed. I have several other citrus such as Ichang lemon that were indoors for the bad weather.
I’m just down the road from mrtexas and my unknown mandarin seems to have survived OK with a lot of protection. Another small tree (which must have died back to the sour orange rootstock when the previous owners lived here) didn’t fare as well and experienced a lot of freeze damage, particularly outer limbs, and it had the same protection as the mandarin. I believe a few limbs did survive but I’m waiting to see new growth to know for sure what made it).