Legal Question in Real Estate Law in California

Tree branches that hang over the property line, as well as roots that grow under the line, are considered by the law to be a minor form of trespass. Usually, courts do not award money damages against the tree owner. However, the law does allow you, the neighbor affected by the "trespassing tree" to take self-help measures. You are allowed to cut the offending roots or branches at the property line, or you may hire a tree trimmer or arborist to do it for you. There is one additional cautionary provision: the trimming work should be done in a prudent and non-negligent way, so that the tree isn't killed, nor become so unbalanced that it is likely to fall over in a windstorm.

"sic utere tuo ut alienum non leadas" you can use your property but not when it affects other people. The branches and roots are trespasses. They are encroaching on your land. There is no statute of limitations here because it is continuing trespass.

As for leaves in the pool and seeking $ against him you would have to prove damages. Thus ask him how he would like to pay for cleaning your pool (just to remove leaves) every week? Those are some damages you could seek from this trespass. Other than that until your fence is affected you would be wise to cut the roots and branches which cross the property line but not on his side of the fence. Maybe he split the cost or removing the tree?