Freeze Damage of Citrus Trees
Freeze damage on citrus trees occurs when water inside the fruit, leaves, twigs and wood
of a tree freezes rupturing the cell membranes. Unlike deciduous trees which protect
themselves from cold by shedding their leaves in the fall and entering a dormant state,
citrus trees continue growing year-round. Extended periods of cool weather prior to a
freeze may allow a citrus tree to prepare somewhat. This is why sharp freezes following
warm weather are more damaging than gradual temperature changes. However, virtually all
freezes will cause damage of some kind. Regardless of what steps you take, there are
times when nothing you have done helps and your citrus is damaged by freezing. However,
as long as the damage is not too severe, your tree can recover!
One of the keys to dealing with freeze damage is not to do something right away to but to
wait awhile until the extent of the damage becomes apparent. In some instances, twig and
branch death from a severe freeze can continue for as long as two years after a severe
freeze. Act too soon and you run the risk of either pruning away parts of your tree that
can recover on their own or missing parts that look healthy enough at first glance but
are really fatally damaged.
The appearance of citrus leaves damaged by freezing can be a little deceptive in that
they can appear firm and green at the outset. It is only later, as they thaw, that they
soften and droop. In instances where the damage is not severe, freeze-damaged leaves can
recover. However, if the damage is fatal, the leaves will loose their structure
completely, dry out and fall.While alarming, leaf fall alone does not indicate tree
death. If the wood remains healthy, the tree will recover and put out new growth in the
spring. As for twigs, damage to the twig will almost invariably result in leaf death. In
the case of serious damage, the leaves will dry out but may stay attached for a time,
several weeks in some cases. However, if the twig is not badly damaged, the leaves will
fall more rapidly.
Signs of freezing damage in branches and trunks include the loosening and splitting of
bark. Patches of damage may appear oozing canker-like areas, occasionally mistaken for
the disease gummosis.
The first step in the pruning process is to wait until late spring or the summer
following the winter the damage occurred. This will give you time to assess the damage.
In addition, freeze-damaged trees occasionally put out a false start of new growth in the
early spring which soon dies back. Delaying pruning until after this occurs will save you
time and energy.
In very severe cases, a citrus tree may be damaged all the way to the ground. In such
cases, the root area may still put out new growth and the tree may, in time, recover.
However, if the original tree was a graft and the tree is killed off below the bud, any
resulting new growth will be of the variety of the rootstock and not of the graft or
scion. It will be up to you to decide whether to re-graft, allow the rootstock to
continue growing or start again.
I am looking forward to hearing from anybody that has Citrus trees, or
anybody that has a question about them.
Thank You for taking time to read my blog.
Saturday, January 16, 2010
The beginning and the Big Freeze events
I wanted my first blog to be about something of real value. The temperatures here in North Charleston, South Carolina went well below freezing for 12 consecutive nights. As many of you may or may not know, Citrus can handle down to 28 degrees for short periods of time. When I say short periods, I mean 3-4 hours max. We are talking 10-12 hours here on some nights. So, with all that being said, I pieced together this information on what to do if your citrus tree received any freeze damage.