How much water per week?

Asked June 11, 2018, 4:59 PM EDT

I have three newly planted baby blue eyes spruce 10" diameter and two black hills spruce 6" diameter. The nursery that planted the trees said 5 gallons of water every three days so 10 gallons a week for the black hills spruce and 6 gallons every three days for the larger baby blue eyes spruce 12 gallons a week. The trees get direct soil light. It doesn't seem like enough water for the hot weather. The black hills have been planted for a week and baby blue eyes three weeks. Thanks, Larry

Larimer County Colorado trees and shrubs

3 Responses

Hi Larry,

The general rule of thumb for newly planted trees is 1-2 gallons of water per inch trunk caliper (measured 6" from the root ball). So the nursery wasn't too far off. You will apply the water AT THE ROOT BALL to keep the roots moist.

Every three days might be enough, but you will have to check the root ball for moisture. If it's too dry, increase it to perhaps 4-5 times per week. If it seems wet, then three days will work. You will need to keep this schedule all summer.

Also, the trees would benefit from mulch, which you'll probably add in the coming days.

http://cmg.colostate.edu/Gardennotes/635.pdf

Hi Alison,
So with 1 to 2 gallons per inch the black hill spruce has a 6" diam. should get around 12 gallons of water per week and the baby blue eye spruce with a diam. of 10" should get 18 to 20 gallons. I know first to check the mositure before watering,do I check the mositure at the drip line of the tree or the root ball closes to the trunk. I'll be getting mulch for the trees this week. Thanks for the info. Larry

Hi Alison,
So with 1 to 2 gallons per inch the black hill spruce has a 6" diam. should get around 12 gallons of water per week and the baby blue eye spruce with a diam. of 10" should get 18 to 20 gallons. I know first to check the mositure before watering,do I check the mositure at the drip line of the tree or the root ball closes to the trunk. I'll be getting mulch for the trees this week. Thanks for the info. Larry

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