。
Green plants can make their own food.
Literal
Green-colored plants [topic-は] their-own [of-の] food [object-を] make can.
自分自身 ('oneself,' with emphatic self-reference) is stronger than 自分 alone. ~ことができる is the formal potential construction. 食物 (しょくもつ) is the formal/written word for 'food,' contrasted with the more everyday 食べ物. Scientific register.