In general, watering plants with overly hot or cold water will shock their system. The best water temperature for plants is room temperature or tepid, from about 62 to 72 degrees.

Germination increases in higher temperatures – up to a point. Once the seeds reach optimum temperatures, which depends on the plant, germination begins to decline. So whether it’s extreme heat or cold, temperature does affect plants and their growth.

Water temperature does not affect plant growth. Extreme environmental temperatures cause the plants to develop at a faster rate, but are those same temperatures are detrimental to the reproductive stage in a plant life cycle. Therefore, water temperature does not affect plant growth.

Don’t water your plants with a glass of ice-cold water. The sudden temperature change can shock the plants. Ice melts slowly, so the water warms to room temperature by the time it reaches the plant’s roots.

The plant’s roots are the most important part of the plant, and if they are watered with water that is either too hot or too cold, it could shock the roots and damage the plant. It will be too cold and will traumatize the plant. The roots will not be able to absorb all the water.

Water for Plants During Winter Just make sure that the ground doesn’t stay soggy, as this situation creates a serious hazard for plants from root rot as well as suffocation. As a rule of thumb, water when the soil is dry to the touch, the temperature is not below 40 degrees F.

Before you head out on vacation, water your plant as normal. Fill the plastic bottle with water, and then quickly turn it over and plunge it into the first few inches of soil in the pot. Make sure the bottle is not too close to your plant and that the bottle is deep enough that the soil covers the holes.