Why Do Plants Need Water & Sunlight to Grow?


Water and light are among a plant's most basic requirements through the life cycle. Insufficient amounts of either element will inhibit or prevent germination, food transport, plant growth, and production of blossoms or fruit.


Germination of a seed begins when it absorbs water, according to Washington State University Extension. Water activates an enzyme that initiates reproduction of plant cells.

Food Transport

Roots obtain nutrients from the soil as they absorb water. The moisture and nutrients are then transported through the stem and leaves to nourish the plant.

Energy Production

Plants use light for photosynthesis, the production of energy. Flowering or fruit-producing plants need much more energy than leafy plants, and therefore need more direct sunlight, according to University of Missouri Extension horticulturist David Trinklein.

Adequate Light

Slow growth and pale or dropping leaves are a sign of inadequate light. Increase the proximity, intensity or duration of light exposure to compensate.

Adequate Water

The first sign of inadequate water is usually curling leaves or general drooping of the plant. Keep soil moist but not soaked for most vigorous growth.


  • Washington State University Extension: Seed Germination
  • University of Missouri Extension: Lighting Indoor Houseplants, David Trinklein

Who Can Help

  • Washington State University Extension: Propagating Plants from Seed
Keywords: plant needs, plant water requirements, plant light requirements

About this Author

Writing since 1981, Dawn Williams is managing editor and columnist for "Chicagoland Senior News." Her work has appeared in the "Chicago Tribune Sunday Magazine," "Country Sampler," "Your Next Step Magazine," "Life Newspapers," the "Kane County Chronicle," and websites focusing on health and fitness, parenting and senior issues.