Best Branch Angles are 45 Degrees from Horizontal (or vertical)

Q. This is the second year for my Santa Rosa plum.  I attached some garden trowels to some of the main branches to open – up the tree to a vase shape.  Is this a good idea?

Weights work good for opening up or spreading open a fruit tree like this Santa Rosa plum growing in Las Vegas. Limb spreaders are faster.

A. Somehow I feel like this was a setup. Yes! If you follow me long enough you know I like to see flower and fruiting plants without their branches growing at 45° above horizontal.  Many types of plum have  narrow crotch angles and their canopy needs to grow more openly.

Some trees grow upright even if they aren't supposed to like pears, many plums, Asian pears and their ornamental counterparts. Good crotch angles form a "U" when they are strongly attached to a limb or trunk. Weak crotch angels form a "V" when the angle is too weak and the limb will split when it gets some weight on it. The branch in the back is growing straight up. No, no, no. Get rid of it now! (and that little one in front, too!)

            Branches growing at 45° angles produce an optimum balance between growth and flower or fruit production. Branches growing horizontally or downward may flower well but don’t grow fast. Branches growing nearly upright (vertical) grow very rapidly but they are slow to flower. The tree intends for this type of growth to give it height. Some trees grow extremely upright (most pears for instance) and the limbs should be spread apart and pruned to outward growth in mid to late spring to slow it down and improve flowering or fruiting.

When young trees or young growth grows too close together and upright, use a limb spreader to push the branches apart for one season of growth.

            Plants don’t care if their limbs are spread to 45° by weights or another method. I prefer to use “limb spreaders” of different lengths (4, 8, 12 and 18 inches). They are faster and less adjustment is needed. You can make them with forked ends out of  one-inch wood lath and even wooden paint stirrers. They should be strong enough to hold branches apart and not break while doing it.

Limb spreaders have a crotch on both ends to help keep the small limb from sliding out. I made this one and it also has a wire brad with the tip cut off to grab the limb better. I now make them without the nail in the crotch. They hold just as well.

            Be careful spreading limbs apart early in the season when they easily split if bent too far. After the new growth in the spring is an inch or two is the perfect time to bend limbs to their proper angle and either a hang weights, use limb spreaders and prune to outside growth to open the canopy wider. After one season of growth in this position they can be removed.