Draughts can be a problem throughout the flower journey, from grower to consumer. They cause the flower’s moisture to evaporate to a greater degree than it can absorb and it will go limp. The stomata on the underside of the leaf regulate not only the moisture and heat that is put out, but also the carbon dioxide and nitrogen exchange with the surrounding air. If there is little air movement, the air layer around the leaf forms a protective cushion against excessive evaporation.

To protect themselves from drying out, plants and trees drop their buds, blooms and leaves. For cut flowers and potted plants this dropping is often the result of over-production of the growth hormone ethylene; the only known gaseous, naturally occurring plant growth hormone. Ethylene gas regulates the ripening/ageing of cut flowers, potted plants, fruits and vegetable fruits. Ethylene gas is therefore purposely used to promote the ripening of fruit and the blooming of potted plants.

Leaves contaminate the vase water, just like stems do. The stem has to be in the water; the leaf, however serves no purpose in the water, in fact, it has a negative effect! Therefore, it is recommended to remove the lower which would otherwise be in the vase water. The additional positive effect of this is that it decreases the amount of evaporation because the total leaf surface is decreased.