We are entering some of the hottest points of the summer and one of the most important factors to keep your trees and plants healthy is water. It could only take one day of extreme weather to kill a mature tree if it is in a stressed state. To many’s surprise, you can also kill a tree by over watering it. In this month’s newsletter, we are going to reiterate some things we mentioned in a past letter but also simplify it in case some of our new readers have not been exposed to the knowledge of watering trees. We hope this information is helpful and takes the guesswork out of watering your trees and plants.
Thank you in advance for taking the time to read this. Our hope is that as we work together you become more knowledgeable and can therefore feel more confident making tree or landscape decisions for your property.
1 – Why Is Water So Important For Trees?
Water is the life source for trees. Water is the solvent for nutrient and food transport within plants. It cools plants during heat through transpiration. It is the primary constituent in the photosynthetic process. Roots and shoot tips only grow when they absorb water. Without water all of these essential mechanisms are interrupted and if prolonged it can kill a tree or plant. Not only will under-watering cause this damage, but overwatering can cause the same issue.
2 – Damages Of Under Or Overwatering
Underwatering:
- Leaves will wilt and could eventually die
- Trees will not be able to grow and will stay the same size
- Leaves will shrink and color will be distorted
- Branches and trunks can be burned by the sun when there is insufficient water moving through the wood.
- Trees have a lower immunity to diseases and pests.
- Roots only grow where water is located and either develop a shallow or unbalanced root system
- Roots start to rise to the surface in search of water and can damage hard-scape.
Overwatering:
- Soils lack oxygen and roots cannot pull water up into the plant. The water becomes unavailable to the plant.
- Roots and trunks can develop root rot from prolonged periods of humidity within the soil. Fungus thrives in this environment.
- Trees will wilt and die.
3 – How do you properly water a tree
I will provide several short tips that I often discuss with clients as we decide how much and how often the tree should be watered.
How much water is my tree used to?
Make sure to keep watering your tree the way it is accustomed too. If it grew up in a lawn then keep a consistent supply of water. If it was used to growing without any water at all then don’t plant a lawn around it. Changing the environment will cause the tree to be stressed and could eventually die. Changes should be slow, not sudden.
Water to the drip line of the tree!
Make sure the water reaches from one end of the branches to the other. Don’t just water near the trunk or one side of the tree. All the roots need water and they can extend to the edge of the branches or further.
Depth Matters!
Trees need to be watered deeply. Don’t make the mistake of watering trees with sprinklers or drip for only a few minutes that only waters the upper few inches of the soil. It’s best to water longer and slower so that the water percolates deeper into the lower 12-18 inches of soil, not just the upper 2 or 3 inches. This can sometimes take a few minutes for a smaller area and a few hours for a larger area.
How often do I water my tree?
Young trees may need water 1-2 times per week, semi-mature trees 2-4 times per month, and mature trees 1-2 times per month. This is a case by case basis as some trees require more water than others.
Soil content also matters. Clay soil holds water longer than sandy soils. If your soil holds water longer it can be watered less frequently.
To know how dry or wet the soil is, you can probe the lower 12” of soil and feel how moist it is. If it is bone dry it is overdue, very wet then it needs more time. Slightly moist is ideal for most trees.
Winter Watering:
Mature trees rarely need winter watering unless it is a very dry winter. Young trees may need to be watered if a few weeks of dry weather go by.