Is there any way to prevent maple trees from producing seeds? I have 2 old maples that are beautiful trees, but I hate the seeds. They sprout everywhere, they clog up the gutters and get tracked in the house. The seeds are produced by the thousands.
Manually thinning of the flowers on a large maple tree to reduce fruiting is dangerous and probably impossible. Setting aside an area under the tree into which the fruit can fall is impractical since the pods can ride a great distance on the slightest breeze. The only means of reducing the fruiting without harming the tree is some kind of chemical thinning. I discussed this in part of my answer to a similar question about reducing the fruit production of an ornamental pear.
Of the options that I mentioned there, only the injectable deflowering agents, Snipper and Pinscher, would be practical for a large tree. Both are specifically labeled for maples, and both were developed for treating mature landscape trees. To be effective, Snipper must be applied each spring as the flowers open, while Pinscher is applied during previous growing season to prevent the following spring's flowering. Since these chemicals must be injected into specific layers of wood just beneath the bark, they should only be applied by a professional arborist.
Note: I have no personal experience with either chemical.