Water competition, Soil vs Roots

[Matt in SD]

I was walking through the garden early this week, after a hot weekend and noticed that the opening spear on a Dictyosperma album 'rubrum' had rotated and was pointing in a different direction (by about 30 degrees) than it was a few days earlier.  Yes I know this means I spend too much time staring at my plants...but...

The next day I looked at it again and this time noticed that some leaflets had lost their shine and were turning sort of brown.  I freaked out and poured some daconil down the crown, then ran the hose on it for about 15 minutes to really soak it.  I watered even though the soil was clearly damp at the surface as well as a couple inches down.  Within hours the leaf returned to it's original position and from marking the spear I can see it's growing ~1" per day...so the palm is fine other than some leaf burn.

But it got me thinking that for people with soil that has a reasonable clay content, is it possible that the clay can outcompete the roots for the available water?  The soil was definitely not even close to dry, yet this palm clearly was lacking water.  I think that when the weather is hot, damp soil may not be good enough if your soil tends to hold the water.  Sometimes the soil may "hold" the water a little too tightly.  

Anyone else ever notice anything like this?

Matt

[Dypsisdean]

Matt,

I noticed a long time ago, that the top 12" of soil can be very wet, yet bone dry 2 feet down. I figured this out when I was planting some 15 gals. in a part of the garden where I had run the sprinklers for 5 hours to make for an easier dig.

Since we all know palm roots go much deeper than 12", this can't be good. So now, depending on rainfall, I will flood the garden once or twice a year. I will turn the sprinkers on all night (about 12 hours or longer). This will not raise your bill as much as you would think, because you can wait much longer until you water again. But at least you know that the deep roots have water, which IMO is more important than the surface. Once it gets wet deep down, it will stay wet a long time. Unfortunately, the reverse is also true. Your plants will never develop deep roots if they never have deep water. This "deep watering" also washes the salt out that otherwise accumulates with frequent shallow waterings.

Next time you plant something big, dig a little deeper and check out the moisture content down there, you may be surprised.

[Bennz]

next time you plant a palm, put a piece of open perforated pipe in beside it, and water down the spout. Deep watering uses less water and has far more effect on plant health than does surface irrigation.

[MattyB]

I noticed a long time ago, that the top 12" of soil can be very wet, yet bone dry 2 feet down.

Dean, that makes sense because usually the deeper you go the heavier the soil gets.   For example the top several inches of my native soil, especially since using mulch, is porus and rich and the deeper you go the more solid packed silt and clay you find.  So, even if you water real good for 15 minutes the water is going to find the path of least resistance, which in most cases is laterally into the adjacent, more porus soil.  So, the flooding tecnique basically sets water on top of an area for a long period of time.  Most of it will go down to a certain point and run laterally, but some of it will find it's way deeper.  Case and point; my Ravenea rivularis has never looked better since I've been setting a sprinkler at it's base on low for about an hour every couple of weeks.  I don't know if this is your problem Matt but it's fun to think about.  Good luck

[Kris]

Dear DypsisDean & Bennz,

I do not totally agree with the methods put forward by you guys.

you will ask why ?

first about deep watering of plants most of the u.s palm website encourage this type of watering through slow drip irrigation.but i have not seen anywhere where they ask you to flood our gardens_this is outlandish.few years back i did exactly the same thing that you are at present advocating and the result,white spongy fungus was seen in all the plants_hibiscus,date palms,areca palms 90% of the plants had to be treated with strong chemical fungicide and kerosine oil.because the ants which were lying low all came out of the ground due to water and for the fungus. my parents,neighbours & friends all scholded me that i was in the verge of killing my garden by my articifical water flooding method. and believe me, i was scared wheather things will go back to its normal state.

May be i was luckier after constant treatment to some extent now life is back to normal.

Now to Bennz,you were talking about putting a perforated pvc pipe or tubing in a ditch and then placing our palms in it.this method is also seen in some web sites.but with difference i.e they use this method for palms like canary island date palm which are forcebally removed from their native place and these are placed in huge ditch with washed river sand and a U bend perorated pipe.these perforation are seen only in the bottom side.and they use it to drain excess water out of palms roots.that is they do not feed water through these pipes.

if plants deep roots are constantly watered you will encounter wilting and palm weeil,bugs & borrer insects grow and damage the plants from down to up.

Natural rainfall and the appropriate season around only help plants, anything artifical will back fire immedietly !

putting perforated pipes deep in the soil is nothing more than asking for trouble.ants,termites,palmetto weeil,other bugs will travell effort-lessly up and down multiplying and travelling in to your soill strata recking havoc.

And friends when i get the info of palm watering i will forward the website address to you all.

kindly do not over water your plants and do not  use heavy dosage of fert this will prove to be detrimental to your plants.never go against nature.

Love,

Kris.

[Matt in SD]

Dean,

I was planning on digging in the area to see if it might be dry deep down.  Typically in my garden, when I dig to plant stuff the soil is evenly wet as far as I can dig.  I have drip and sprinkler watering in most areas which both run every other day (drip runs for 45 min, sprinker goes for 20 min...yes I water a LOT).  But the particular spot where this Dictyosperma is seems to be a tough area to keep wet for some reason.  So you could be right, but now that I've deep watered the area, it will be impossible to tell for sure.

Kris, we are all in very different climates.  For people in Southern California, to "not go against nature" would mean that we would have a very limited number of plants to grow.  We get less than 10" (25cm) of rain on average every year, and 90% of it comes in winter when plants aren't doing much growing.  Soil composition also makes a huge difference for what you can get away with, and what consitutes "overwatering".

Matt

[Ashton]

(krisachar @ Jul. 28 2006,02:11)

QUOTE

They use this method for palms...and a U bend perforated pipe.these perforation are seen only in the bottom side.and they use it to drain excess water out of palms roots.that is they do not feed water through these pipes.

Love,

Kris.

Kris,

I had four 5x5x4' holes dug for some new palms recently. I asked for a ring of perf pipe at the bottom and two pipes coming up to the surface. The contractor forgot to ask me to inspect the pipes and I eventually noticed that he had used perf for the vertical pipes as well as the ring at the bottom. I told him that he had messed up (actual language changed) and he had to go back and remove all the new soil (several tons) and gravel to replace the vertical pipes with solid wall pipes.  Some people just don't get it.

ashton

[Bennz]

Kris,

some palms like water, I have often seen Archontophoenix cunninghamiana growing in streambeds where they have been submerged all of their lives. Rhopalostylis sapida grows here in swamps which may be dryish for only a months or two at a time. For palms like these the deep watering works well, especially in dry summer cliamtes.

Personally I admit I just plant palms and forget them. They usually survive, but my climate is milder than SoCal so not so much water stress. My average rainfall is around 65mm in the dryest month, which is usually enough to keep things alive, if not actually thriving.