If a plant lacks water,the leafs shrivel up.Will it affect the top leaves first or the bottom leafs. Explain?

Answer 1

it should effect the top leaves first. water is drawn up through the plant like a straw. evaporation through the leaves draws more moisture, from the ground. A lack of moisture will reduce the draw effect, and those near the top will strain to pull beyond those of the lower branches. In a drought you will ofter see the tree tops stressed.

Answer 2

Undoubtedly, in the first photo that is a Periwinkle vine. The second photo appears to have a low growing shrub. Periwinkle grows as a groundcover. Of course, it might have grown up and covered a shrub in the second photo. I've not seen Periwinkle do this, but I suppose it's possible. Periwinkle has a root sysrem like cast iron so wherever you plant it, expect to pretty much leave it there. If the vine starts expanding beyond where you want it, simply pull those wandering bits of vine and set them in the ground elsewhere. It roots easily and grows readily. I love it, can ya' tell?? :)

Answer 3

Probably top leaves first since the water is absorbed through the roots and is then pumped up from the forces of transpiration. The water will pass by the veins of the leaves closer to the roots, so those leaves should be able to get water until there is no more.