Zone with Trees & Shrubs- What Crop Coefficient?


#1

I have a drip zone that waters both the Trees & Shrubs. Should I splint the difference of .75 & .55 for a Crop Coefficient of .625?


#2

@Silent. I think 0.65 is a good place to start. You could then watch between waterings to see if either show signs of distress just before the next watering. Based on that you can adjust one way or the other. I’m doing that now with my shrub zone that has a decent spread of coefficients.

It would be nice to separate those trees to a different zone if you ever get the chance. Do the trees at least have more emitter heads to them? They’re roots are deeper and spread more widely, so I would think that they’d eventually suffer.


#3

Yes, the trees have 3-4 emitters on them while the shrubs have 2.


#4

Or do the tree emitters have higher GPH? I have shrubs mixed in with my perennials (and one tree), and while most of the emitters are 1/2 GPH, I have either 1 or 2 GPH emitters on the shrubs, and the tree has I think 4 emitters.


#5

How do I tell? The system was installed by someone else.


#6

That’s actually beyond my skill set! The ones that I’ve bought were color coded from Rainbird. Black were 1/2 GPH, red I think 1 GPH and beige 2GPH (but I’d have to find the packaging and check that) - I have no idea if that is standard or not. Perhaps @plainsane would know?


#7

They aren’t standard, companies use different colors. They should be on the emitter itself but it’s pretty small and if the emitters are older it may be hard to make them out.


#8

I’ll add that if you can’t make out the markings on the emitter itself you might be able to tell by how much water it’s releasing either visually or by running it for a set time into a measuring cup or something like that. There are visual guides that show what the different flow rates look like but I’ve always found it hard to tell the difference between the different emitters unless the rate is pretty different.


#9

Thanks, @JPedrego! I knew that one of you smart hardware guys could probably answer this !!! (I’m the same with my watering as I was when I was working in IT – great software skills, but I only got by in the hardware area!)


#10

Ha! I think that’s the first time I’ve been called good with hardware.


#11

One last thing before I stop flooding this thread with replies, as Linn mentioned, if you do know the brand you could probably look up the color coding on the companies website.


#12

Thank you! Time to go digging around in the yard :slight_smile:


#13

You should always irrigate to the plant with the highest water requirement.


#14

Post a pic of the emitter


#15

In case you can’t find identifiers on the heads, @Khillski posted this method. I haven’t used this method yet, but plan to give it a shot.