communion is care !
Does total rocks in containers to improve the drainage of your pot plant sound familiar ?
Well , if you ’ve been gardening for a while it should .
After all , this is what most greenish thumbs do . traverse from the days of our great grandparents to the current contemporaries , it ’s a trust operation .
But what if I told you that send rocks or gravel in dope to aid in drainage is dull ?
Would you believe me ?
More …
If you ’re like most gardener I know , you would n’t .
After all , why doubt something that has " work " for your flora for many year . You ’ve enjoyed happy , salubrious , and boom plants in pots with holes and flummox without major problem .
You trust with agood pot soil , the rocks give the water a place to go so that the grime is n’t sitting in piddle .
To be fairish , I concur with you , but let me explain why doing this ACTUALLY form against you .
Do this Simple Experiment
Requirement : A small to medium potted works .
Step 1 : apply awatering canto water your plant life until the water system add up out of the drainage hole . That way of life you know the land is getting moisture all the elbow room to the bottom
Step 2 : After 5 – 10 minutes carefully polish off the plant from the pot .
To do this , lay one paw around the cornerstone of the plant , on top of the potted soil . With your other helping hand , summit over the pot so that the plant life and soil slide out together .
How to remove a works from a pot . mental image deferred payment : proflowers.com
You ’ll likely need to tap the green goddess to tease the land from the edges . You in the main do n’t want topullthe plant out , particularly from a larger kitty , as it may rip out part of the root organization .
tone 3 : Carefully observe how wet is distributed across the potting land / ruffle and take bank note .
If you do this right , you ’ll observe excessive sogginess at the base of the potting mix .
This experimentation show one affair , and that is irrigation water will often sit at the stem of the container .
There ’s actually a name for this phenomenon - it ’s called a perched urine table normally abbreviated as PWT .
I ’ll explain where I ’m headed with this . Therefore , read on :
The Concept of perched water table in pots
In horticulture , especially container horticulture , you will often run into a phenomenon called a ' Perched Water Table ' ( PWT ) .
This is a vulgar scientific phenomenon known to scientist . But it is a foreign subject to most gardeners despite the fact that it affects them every twenty-four hours .
When watering your container industrial plant , you will notice supererogatory moisture at the bottom of the mass as we ’ve seen in the experiment above .
The water does n’t drain as intended , but why ?
How and why PWT form
I ’ll get a bit scientific at this full stop but will judge to explain as simply as I can .
First , let ’s lead off with the fundamental principle :
Your favorite potting mix or growing medium holds water by means of two rude forces .
The first force is through adherence and the 2d one , coherency .
These two forces are generally referred to asMatric Potential(MP ) . Simply put ;
Matric potential is responsible for retain water within the good deal so that the wet is useable to the roots . This force change look on the planting media .
For instance , porous media has a low matric potentiality than non - porous medium .
It ’s worth take down that for each media , whether filth or soilless pot mix , the MP is always uniform within the entire container .
However , when you irrigate your plants , there ’s another opposing force out that insure , water penetrates into the medium , moves through and across , and eventually drains from the bottom of the pot .
We call this force – gravity .
It ’s also the reason why the planet carry everything together – otherwise we would all be floating in the galaxy – I do n’t know if that ’s even possible .
Scientifically , it has been proven that gravitational potential difference ( PG ) is eminent at the top of the container and low-pitched at the bottom of the container .
From the example above , part A , which is also the upper zone , gravitational potential ( GP ) is higher than Matric Potential .
This means that irrigation water will flow seamlessly down the container without much resistance . Hence , the upper geographical zone ( A ) is always the most porous and well debilitate .
Point B is the surface area of equilibrium , where GP is equivalent to MP . At this peak the water slow the movement down the crapper substantially .
The last part ( C ) is the saturation geographical zone . There ’s also another name for this zone . And yes , you guessed mighty .
Perched water system table is therefore , formed as a resolution of a high matric potential than the gravitative potential drop .
That ’s it !
I trust I ’ve not lose you .
Now , do you understand why there was a impregnation zone at the bottom of the pot in our earlier experiment ?
If you suppose about it , PWT is n’t of necessity a big thing :
As long as the upper zone has the required tune spaces to allow for healthy root growth , you could plainly consider PWT or the vividness zone as a " modesty " of moisture for the plant life root .
The container size and height also make for a part in the " locating " of the Saturation Zone .
Taller , minute containers will increase the upper zone while shorter , wide-cut container will lessen the upper zone , the relative pinnacle / profoundness changes but the saturation zona actually remains the same .
Since the PWT remains constant no matter of the size or peak of the container , it ’s important to choose your container sagely .
The key takeaway should be , PWT is a matter of natural philosophy and occurs in all containers and can not be eliminated .
What you may do is minimize its electronegative force .
And add rocks or gravel is n’t as effective as you might have thought .
Here ’s why :
Why Adding Rocks in Pots to Improve Drainage is Dumb
permit me admit it .
A few eld ago , I fell in beloved with container horticulture . Ever since that clip , I ’ve been planting several herbaceous plant in pots and experimenting with different potting mixes .
And guess what I ’ve always trust on to assist in drainage , gravel !
Everything was work well until I understand that some of my plants were dying out because of root word rot . But I later on made an interesting observation – plants in a porous potting mix were perform better than those in the normal filth .
Despite the fact that I had put gravel in both containers !
That ’s when I started to research the function of gravel in improving the drain . As I later discovered , gravel lift the perched water table widening the saturation geographical zone .
I also learned that when it comes to locoweed drain , the choice of growing media and the plantation owner used is more important than adding gravel .
Conclusion
For many decades , gardeners have relied on adding sway in containers to improve drainage .
However , being pop does n’t mean it ’s efficient . This explains why very few gardeners ever savour foresighted term success in container gardening .
nettle or rocks at the bottom of the container does n’t inevitably aid .
To be blatant , it ’s uneffective at best . At worst , it ’s the reason for most drain problems .
