Janice Lewis  age 12 Douglass AZ

How does frost kill plants?

The leaves and buds of a plant are fed by sap. The sap is liquid carried up from the damp ground below. It runs through the whole plant in a network of veins. The veins of a leaf are full of liquid sap„ There is also moisture in the cells of the leaf.

Frosty weather turns liquid water into solid ice. And solid ice takes up more space than the liquid from which it was frozen. Frosty weather will sometimes freeze the water in the bathroom pipes. When this happens. the ice may break the solid metal pipes. The liquid water expanded as it froze.

Imagine what happens to the fragile veins of a leaf. The temperature drops to 32 degrees Fahrenheit. The liquid sap becomes solids maybe full of sharp slivers of ice. The delicate veins are torn asunder and ruptured. Never again can they carry the sap in an unbroken stream to the cells and tissues. When the frozen sap melts  the broken plant tissues wilt and perish.