I recently bought a rain barrel soaker hose kit from: http://www.mrdrip.com/Rain-Barrel-Hose_c_631.html

The soaker hose is meant for rain barrels or gravity-fed systems. However, after following the instructions and testing it I discovered that barely any water comes out of the soaker hose. Small beads appear, but even after leaving the valve open for several hours, there’s barely any water on the ground. I have the rain barrels about 18” off the ground and I’m just watering 2 small beds with perennials for now.

I called customer service and the guy recommended having the barrels at least 2’ and preferably 4’ off the ground. He said they need more water pressure and higher elevation would achieve this. However, my wife isn’t crazy about the aesthetics of having them raised up so high.

Rather than adjust my barrel height, it seems logical to me that poking small holes in the hose right around where the plants are would allow more water to flow into these areas. I can’t find any info or examples of this being done on the internet- most FAQs I’ve come across discourage doing this but I’m not sure why? Anybody have a similar experience or any advice to offer?

Thanks!

Raising the barrel will increase pressure, which will make the soaker hose drip faster.  Soaker hose is not
supposed to "spray". It is meant to "weep" water thru the whole length.  You need a "drip" system that has
spaced holes if you want to water individual plants.

The problem is water pressure, you don't have enough "head space" at only 18" above ground level.
You could use a 1/8" drill bit to open the holes more but then you are going to be stuck with a single use hose since the holes will work correctly only with that rain barrel at 18" above ground level.
If that isn't a problem for you, then go ahead and make the modification, it is only going to cost you the time it will take to open the holes to 1/8".
Be aware that there will never be any streams of water coming out of the hose, it will be more of a drip irrigation set up because of the low water pressure, but it will work better than it does now.

Redhawk

Eighteen inches of height will not produce much pressure.  You need a height [head] of 2.3 feet just
to produce a gravity-fed pressure of one psi

I have several old soaker hoses still in use after several years.  Even with good pressure, minerals and other gunk can build up in the hose and gradually clog the pores.  I have often punched holes in it near thirsty plants, using an ordinary sewing needle or perhaps a heavier needle, nothing larger than this, which will create too much of a leak.  Perhaps at your pressure you might need something larger, just play around with it.  If there is a spray you can lean something over it to direct the water downward, or wrap a rag around the hose there.

Thanks All for the info,
I'm going to take a section of soaker hose I'm not using and experiment with hole sizes to get the right drip, and then apply this to the hose around the plants.
I have my barrels all rigged up on a platform, and a Y diverter installed on the downspout, so it would be kind of a pain to raise them up. Plus, my wife would not be happy about it. So this seems like an easier solution.

I'll post my results later.

From my experience, soaker hoses and drip irrigation is not a good fit for rainwater, especially not gravity fed rainwater.

The main problem is, even with a good roof washer, you end up with a lot of silt, dust, grit, etc. in the water and this tends to plug up drippers, small holes, etc.  You could run the water through a filter, but that requires pressure, which you don't have, or really large filter surfaces.

One possible option would be to make a water tower that is fed by a small pump (perhaps powered by a solar panel) from your set of barrels,  You could tank a plastic barrel and disguise it as an old style wooden tower, that might appeal to your wife's aesthetics.


Another option would be to run a small pressure tank and pump, but that requires more power.

If you are watering larger, fixed plants, like trees/shrubs, then you might try using 'bubblers', they are less likely to get plugged up and will work well with practically zero pressure, but tuning them so they all produce the same amount of water is tricky and time consuming. 

Finally, there is always the manual option (our primary way of watering with rainwater), i.e. buckets, or a hose that you move from plant to plant.

Note: Most people are in business to make money.  Just because they sell something they call a 'rain barrel soaker hose" doesn't mean that it works well in that application.  Google "Laundry balls" as an example of something once sold that the sellers KNEW didn't work.