I have 2 red palm trees for 6 years already, they don’t seem to grow well but the small trees beside them grow a lot. Can someone advice how to care and grow them into final state of 4-6 tall red palms each?

1. What’s the right way to cut/prune to the final state?

2. Do I need to prune the small trees (suckers?) beside them?

3. Is putting small white stones around the tree harmful to the tree’s growth?