Question
Our Ornamental Plum Tree produces plums that create a huge mess.  Is there any way to sterilize it so it won't produce fruit?  The fruit isn't good for anything. We don't want to get rid of it, because it is pretty and we love the shade.  Thank you for your help.

Answer
If you want this tree to be an ornamental
flowering plum instead of bearing friut then spray Gibberellic acid
(Ga3) about a week after petal fall. Naphthalene acetic
acid (NAA) is a more complete chemical thinner
applied at the same flowering stage. Both the above
are growth hormones and are not considered restricted
use pesticides.
Here is an artilce on thining fruit on apples the same concept can be applied to plums but instead of thining use a heavier spray on all flowers and this should wipe our the fruit.
http://www.umass.edu/fruitadvisor/factsheets/Thinning/