1、你给的句子有失误,可以有不同改法：
The beautiful garden 【is】planted with so many nice trees and flowers.
或
The beautiful garden planted with so many nice trees and flowers 【opens】from 8:00 a.m.to 7:00 p.m.
2、句子成分分析：
【The beautiful garden主语】 【is planted with被动式谓语 】【so many nice trees and flowers 宾语】
【The beautiful garden主语】【 planted with so many nice trees and flowers过去分词短语,定语】 【opens 谓语】【from 8:00 a.m.to 7:00 p.m.时间状语】