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Watering Your New Beautiful Trees and Shrubs

Hot and windy weather can be very stressful for newly installed beautiful trees and shrubs.  Newly planted trees and shrubs require more water because they have such a small root system. The root system is actually a very important source of both absorbed and stored water for the plant.  Roots need to absorb enough water from the soil to support the plant daily, and much of a young plant’s needed nutrition comes in as dissolved nutrients within that soil water. 

Hot, windy and dry weather depletes soil of its moisture, making newly planted nursery stock very susceptible to root mortality!  Once roots desiccate, they die.  The more roots that are impacted by desiccation, the less water is absorbed and translocated up to shoots and leaves.  This leads to wilting and stunting of leaves and eventually, leaf drop and stem dieback.

To prevent root desiccation, newly planted stock requires irrigation every second day when temps are 29C or greater, especially when conditions are windy.  Winds can significantly accelerate the rate of evaporation of soil moisture, especially when its hot outside. See the chart below for some suggestions on how to water your trees with the irrigation system that you have. 

How Much Should I Water?

The amount of water needed to replenish soil moisture depends on

  • how dry the soil is (dig down 20 cm and feel for any moisture)
  • the air temperature and soil temperature
  • the amount of drying winds
  • the amount of weekly rainfall

Established trees and shrubs require about 2.5 cm of rain per week during modest growing temperatures (15o-22oC).  If the temperatures are higher and/or the trees and shrubs were recently planted, soil moisture requirements will be much higher.  

How Does Mulch Impact Soil Moisture?

Eu Hornbeam New TreeMulch is an effective weed barrier, it can help maintain soil moisture too, but if soils are allowed to dry out under the mulch, this means that it will take extra water to replenish soil moisture.  The extra water will be necessary to saturate the outside of the mulch before the water can run down into the soil below.  Make sure the water is getting PAST the mulch and DOWN into the soil of the root ball by adding extra water.  You can break the irrigation events up into two or three watering times (see chart above “How Long”) in order to increase soil infiltration. 

You can also scratch the mulch away exposing spokes of bare soil around the tree stem (much like the spokes of a bicycle wheel), in order to help the water to more fully infiltrate into the soil.  Remember to replace the mulch back over the bare soil when the heat spell is over.   

What Time of Day Should I Water?

Beautiful Trees OfficeMoisture loss is highest during the afternoon when hot, dry, windy weather creates perfect conditions for evaporative water losses from soils or plant surfaces.  By irrigating in the early morning (e.g. dawn), you can help the soil compensate for water lost the previous day and help your trees recuperate quickly.  Morning irrigation is beneficial since leaf pores (stomates) are open at this time and plants are harvesting carbon from the air to transform them into sugars, a process known as Photosynthesis. Leaf wetness periods will be much shorter in the morning, reducing the potential for disease.   

Although some property owners prefer to irrigate during the evening, the result is an extended leaf wetness period all night which often leads to foliar diseases.  These preventable foliar diseases can reduce the health and aesthetics of our beautiful trees. 

What Time of Year Should I Water?

Tree and shrub roots will be absorbing soil moisture and growing new feeder roots any time from February to November.  Evergreens (like pine and spruce) roots can be actively growing into December.  To keep your new beautiful trees and shrubs happy and healthy for many years to come, we recommend monitoring soil moisture and irrigating dry soils from May to the end of October.

Contact Us Today

Call us today to book your free on-site estimate to protect and inspect your beautiful trees and shrubs.

Watering Your New Beautiful Trees and Shrubs

Contact Us Today

Contact Us Today for Quality, Professional, and Experienced Tree care. Where you and your green space are our number one priority.

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