I have a desert willow with a branch that split at another more substantial branch. Severe winds. It did not break all the way through. Will it likely heal or should I prune it. Thanks.
It won't "heal", but it may hang in there without completely splitting and falling. It depends on the severity of the split and how much end-weight and movement there is on the branch. Here are some options:
Prune the end of the branch to moderately reduce weight and wind resistance. This will prevent the weight and movement worsening the split.
If there is not a great deal of separation and twisting preventing it, drill through both sides of the split and install a "through-bolt" or two with washers and nuts to prevent further splitting.
Install a vertical prop, or A-frame support, from a solid footing at soil grade, to artificially support the split branch and prevent further splitting.
Remove the split branch at the point of bifurcation with the parent limb. Don't cut into the parent limb to achieve this.
If the parent limb has sustained a severe wound from the split, consider one or more of the above.