Right now I have a number of 4x4x12 raised beds, each has one has one fruit tree in it, and around each tree is one loop of drip tube.
I have been trying to figure out how long I need to run the system, to completely saturate the bed, so that I can be sure that all of the roots within the space of the bed itself get water.
The beds are open at the bottom, but all I want to make sure of at the moment is that I can completely saturate the beds themselves since that is where so many roots are.
Today I ran the drip system 30 minutes at a time, trying to gauge when the beds would finally be saturated. After every 30 minutes I tested by attempting to drive a wooden skewer down at different points of each bed the entire 12” length.
I ended up running the system a total of two hours, and what I found was that after two hours, the beds with the youngest, least developed trees were totally saturated. I could easily drive the wooden skewer down at any point.
But this what not the case with the trees that are larger and have more extensive root growth. Even after two hours of the drip system running there were still lots of areas which stayed dry and hard, into which I could not push the skewer. I ended up having to do overheard watering to get those areas moist enough that the skewer would go in.
For those of you who are also using loops of drip tube to water your trees, how long do you usually need to water? After two hours should I still be having dry areas in my raised beds? Does it make sense to keep running the system more? I was so surprised at what I discovered after two hours that at this point I’m wondering if even after 3 or 4 hours those beds would have been totally saturated!
Does this mean I need to add more tubing to the beds with the more mature trees - is one loop not enough and I need two loops in those beds? Or what would be the best way to address this?
Drip tubing comes in many flavors. Usually, it’s a tube with a emitters spaced along it at some interval. Each emitter gives however much volume of liquid for every unit of time (usually listed as gallons or litres per hour). Sometimes this varies depending on the pressure in the system, sometimes not. Check the labeling of your specific tubing to see if the numbers make sense compared to how much water you would expect to have to spray with a hose or watering can to get it wet enough.
Also consider the positioning of the emitters themselves - it might have had problems soaking around established roots or harder packed soil in the established beds. You might also consider what time you are running the system and whether evaporation is a factor. Even a drip system will wet things better when it’s cool and dark than hot and sunny.
But as a rule, no, running a drip system for more than two hours isn’t unreasonable. It’s better to occasionally water deeply than frequently water lightly.
Finally, there’s no reason you can’t just add more emitters / tubing to the beds that need it. Probably easier than running it too long and drowning your other beds.
As @PlantingOaks said, total water is a function of output and run time. As I recall in the other thread you said you were emailing dripdepot, they may be able to help you with the output if you’re having trouble/it’s not as easy as “well, I have 10 1gal/hr emitters”
In addition to what they mentioned, I’m wondering if you have clogs or broken emitters or if the bed was like bone dry and needs to get saturated/rehydrated and it’s not so much about “maintenance” run times. Or if it’s something as simple as the hose isn’t all the way open or something
Yes, I’m still in communication with Drip Depot, because I’ve been purchasing parts from them to set up the drip line for my container trees (now finally finished!).
A couple of these drip lines that are in loops around the trees were set up by a landscaper, and I don’t have full knowledge of what he did. I know they are Netafim drip tube. What I did notice examining one of the loops is that water seems to be coming out fairly steadily from some of the holes, yet barely dripping from others. Even output usually means a pressure issue right, the pressure is too high or too low? I’m wondering if he set things up improperly. Maybe the line requires a pressure regulator or something? I’m examining it and trying to figure out what he did exactly. That’s a good idea about contacting drip depot about this as well, maybe they can help me pinpoint the problem.
I should mention though that it’s all the beds with mature trees in which I’m finding dry hard spots, even those he didn’t set up, and I’ve verified the emitters are working fine in those beds.
So that’s the basic situation: the beds with more recently planted, less mature trees do seem to be getting totally saturated after I run the drip system for that length of time but in the beds with more mature trees lots of dry, hard soil, which I only seem to be able to loosen up and moisten through overhead watering. I don’t know if that means the drip system as currently set up is suboptimal for those trees, or maybe it doesn’t matter as much because they are more mature, and their roots probably extend a lot deeper into the ground below and are drawing water from unseen depths?
I was running early morning, but I’m guessing evaporating isn’t a huge factor in these cases, simply because the beds are mulched with several inches of wood chips.
I haven’t experienced any run off from the beds, so risk of anything drowning so far as I can see. Even after running the system for 2 hours, there is no sign of water running out of the beds.
What I did notice is that on one of the beds with netafim tubing set up by a landscaper, the water does not look like it is coming out evenly from the holes in the line. It issuing at a faster rate from the first holes and barely at all for the one further down the loop. Pressure issue?
Could it be that the more mature trees with more extensive root systems - that their roots are simply drinking up all the water as soon as it’s applied, so it’s not getting a chance to move laterally through the soil as much?
The uneven output sounds like it could be a pressure issue or partial clogging. Worth flushing the lines with the end caps off and seeing if that evens things out. If some emitters are still barely dripping after that they might just need replacing.
It could very well be a pressure/clogging issue. Personally, I found the tubing with built-in emitters to clog quickly with our very hard water, so I no longer use it. My mother also had problems with a different type of emitter tubing dispensing unevenly over very minimal elevation changes.
I personally like the emitters that can be taken apart to unclog them or just sanity check that they are getting good flow. (i.e. Ceta PC emitters, Flag Emitters , or Shrubblers)
It’s also worth keeping in mind that there are many landscaping companies that will install a drip system, but don’t really specialize in them enough to design a good one. What is the layout of the problem beds? Are they at the end of a line? Could you be trying to output more water over various branches than the main tube can carry? I saw you said there are still beds with dry spots even with visible flow, but is it possible it is a lesser flow?
My understanding is that a pressure regulator decreases pressure in the system to avoid, say, shooting off sprinkler heads or damaging fittings by having too much pressure with nowhere to go. I would not expect one to help with not enough flow.
If you don’t have enough flow to do your entire system at once, you split it into phases and do one section at a time.
Or get lower-flow emitters and run the system for longer to get the same ultimate output, but the first solution is probably more practical if you already have something set up.
i just have 4 “sections” that i water but to run the timers is kind of a pain since i prefer the manual timers that you turn by hand (I’ve had multiple “programmable” timers just fail)
ugh. tell me about it. Timers are so great when they work, but they only seem to work for a year or three then just fritz out. And not cheap to replace! If anyone has found a model with some longevity, let us know!
I’m thinking next round I’m going to try building my own with a microcontroller and pieces-parts, so at least I can replace it partwise rather than chucking the whole thing. (and get more granular control over the programming - what do they mean all the runs have to be the same duration?!)
i have the ones where you turn it and it ticks down. these have lasted 5 years! they were only like 5 bucks. the ones with any kind of screen or whatever never last more than one year for me.
i have low water pressure so it’s a bit of struggle. plus hand watering one area from the rain barrel, i haven’t found a good way to connect it with enough pressure to get it to water along that side from the barrel
the raised beds i put in worry me I’ll have to set up a real irrigation method for them instead of soaker hoses along a mound on the ground