I have four boys, and struggle to get them all involved! We are starting over on a new, .25 acre property, and my (pre)teens are not at all interested. Ages 2 thru 7 always want to be put with me, but 11 hits and it's a chore.
Briana you might find this thread helpful City Kids Turned Farm Kids there are a variety of different ideas in this thread. Maybe some of the ideas could work for you.
“No hour of life is wasted that is spent in the saddle.” Winston Churchill
Opportunity is missed by most people because it is dressed in overalls and looks like work - Edison. Tiny ad:
It's a bit like "run away to the circus" but with gardening