large irrigation systems

[fattyphatcakes]

I had somebody ask me about installing an irrigation system for for a row of blue spruces he planted about 5 years ago. The row is 2500' long, trees planted on 30' centers and are about 10' tall. (yup, that's 80-something trees) This is the north border of his property adjacent to natl' forest. I havn't seen the propery, but from his description it gets full sun, probably has some slope but nothing too steep. He said he's been trying to water them once a month, but needs to automate the process.

His question to me was about what depth he should water. I recomended no deeper that 10-12 inches. This brings up the question of how to install the system such that it is operable in the winter. I don't know much about irrigation, but I can think of only 2 aproaches. Either bury the system 12" deep and drain it after each use, or have the water source burried deep enough that it doesn't freeze, and have each drip line go up to a 10" depth, with something setup so that after the water is turned off that line will drain.

By irrigating these trees is he committing him self to irrigate forever? This area is semi-arid, if he, or a future property owner decides to stop irrigating I think these trees will have major problems.

He spoke with an irrigation company before me and they didn't really know how to go about it either.

Any suggestions on where to learn more?

 

[wct4life]

Just acouple of thoughts...

First, if they were planted 5 years ago, they should be established well enough to survive on their own.

Second, I was always taught to water deeply, infrequently for trees. The idea is so that when you ween them off of water they'll be able to fend for themselves. And when there are mini-droughts the roots won't be so easily affected.

Third, Do you really want to go through and cut all of those existing roots? Nah.

Forth, as for winter irr. I don't know how cold it gets where you live but, the pipes would have to be safely below the frost layer. In OH, if you have Irr. it has to be blown out to stop the pipes from breaking. City water has to be buried below 36" to still be able to function in the cold. Even then there are problems.

Fifth, you don't need to irrigate plants forever. You shouldn't just stop it when you want though. See second for further explaination.

Hopefully this'll help you out alittle. Or It may just raise more questions.

 

[arboromega]

if i did my math right that should be around 83 trees. that is alot of individual irrigation heads. very costly to the client.

 

[fattyphatcakes]

I would agree with you that you shouldn't need to water after 5 years, especially in the foothills. I would say after this first 5 years it's survival of the fittest. And I would guess he will change his mind when he finds out about the cost. 2500 feet is almost a half mile. Also water isn't exactly abudnant around here. I should have asked him what his water souce is. Most people have wells up here, he could run the aquafer dry. People want to do some wierd things sometimes.

However, his call made me realize that I need to learn something about irrigation systems.

Hypothetically, how would you do it?

I don't think it's neccessary to put the lines deeper that you will water, so long as there's a constant slope so all the water can be drained with no pooling anywhere in the system. That's what the ski areas do for snow making, so long as the water in the system is moving freezing is not a problem.

 

[TreemanFJR]

What is the intended purpose of these trees? A privacy barrier on his property?

They are more shade intolerant and they do favor the moist and rich soils. They are dominant but doesnt apply much in your case since you dealing with a single species. In dry areas like yours a recommendation for blue spruce is it should be watered once a week for the first five years. Above ground around the base of the tree.

All in all it is not a very sensitive tree. It will grow in all different soil types. It can grow in dry, moist, or wet conditions. Accepts a pH range of 3.7 to 6.5.

A couple simple things you could do would be to:
- Add mulch or organic matter. This will increase the water holding capacity around the tree.

- Remove the grass away from the base of the trunk. This almost goes hand in hand with mulching. Grasses compete for water with the tree.

- Avoid soil compaction. I doubt this is affected much in your case. This compacts the pore space and cuts off the oxygen supply.

Drip systems seem to be popular on plantations. Not exactly sure if they work under 32 degree or not. Yah it's expensive. So you are probably right about not needing something that extensive.

Im not to sure about the pooling of water. I can see good things on both sides. But if the water is moving too fast through the soil it may be leaching right into the groundwater, which would be a waste.

This is a great question. Il'll see if I can find more information to help you out

 

[Nickrosis]

Forget irrigation. You're in Colorado for goodness sake.

If he wants to water them, he should get a water truck with 1000 or 5000 gallons and water during drought periods if it's necessary. For the cost of an in-ground irrigation system, he could pay for many years of periodic watering this way.

Should this not satisy the guy, talk to him about traveling sprinklers that would do the job. Sports fields use them, but you can also get homeowner sized stuff from Nelsons that might work for him (with an awful lot of hose). To do this, though, he'd need some incredible water pressure, and he'd only benefit a little in automation.

http://www.lrnelson.com/products/models.cfm?SUBCAT=6
They make stylish models.

Irrigation is expensive! One customer of ours is looking at $30,000 for her lawn. We're looking at $25,000 for our grass and nursery holding area. Not cheap.... and there are many alternatives.