If your ZZ isn't standing tall, it might just be feeling a little cramped When roots run out of room, new growth slows down and the branches can start to droop. Root exudates: the hidden part of plant defense ScienceDirect Garden Plant Families Apiaceae the Parsley Family Miles Away Farm Blog Best Low Light Indoor Plants for Home or Office HGTV Photosynthesis & Oxygen Production (Daytime) Most trees and plants produce oxygen during the day through photosynthesis, which requires sunlight. They absorb carbon dioxide (CO) and release oxygen (O). What Happens at Night?