Shop Products
Houzz Logo Print
saoodhashim

Watering Potting Soil

saoodhashim
10 years ago

As I have seen a number of times that whenever watering container to water it until it starts to drain from the bottom.

However, one thing I note when I water the the potting soil (and I have tried three different potting mixes) is that they retain a lot of water. By just compacting it a little (while it is draining from the bottom), it releases a lot of water on top of the soil. Is this something normal with potting mixes.

Yesterday I bought a Rapitest mini moisture meter (measuring on a scale of 1 to 4 - with 1 being dry and 4 wet). I have not watered the plants in my pots for around three days and it has been around 105F at noon these days. While I have kept the pots under shade as soon as the temps go above 90F, when I checked them with this tester, I found it around 4. Also the top of the pots of one of my tomato plant has been blackish (the color of the soil when it is watered) and not the typical brownish when the soil has dried up.

Is this something normal with potting soil? What can I do to ensure that my plants are not water logged?

Comments (14)

  • oxboy555
    10 years ago

    Welcome to peat pudding! Even in the desert, that stuff is still going to hold water for too long. You should probably read through Al's post on Improving Water Retentive Soils.

  • saoodhashim
    Original Author
    10 years ago

    Thanks Oxboy for the reference to Al's post

    After reading it, I understand that the PWT is approx 3 inches from the bottom for most of the potting soil (I think it would be more over here - more like 5-6 inches). So now what should I do? As I understood the water drainage can be extended if we tilt the container or insert some wick from the drainage holes - but that will happen immediately after watering - and not three days after watering (as is my case). As I see now, one of the pots' surface soil has even started to show greenish look - most likely fungus as a result of over watering.

    The local nursery guys were like shocked when I told them that I water until it starts to drain from the bottom as that's what I learnt from experts in the US :-). They told me to immediately stop it. Perhaps the local potting soil is not like Miracle gro type - here it hold too much water and may have been designed to suit local desert climate needs as to store more water to keep the plants cooler.

    What should I do now? for these plants that I already have and for the plants that I am going to transplant very shortly? I really am afraid of making my own potting soil (it is becoming too much for a beginning gardener) - the best I can do is take the potting soil readily available and mix sand or perlite / vermiculite (as all of it are available in the local market)? Will that increase the drainage? Should I actually be watering until it drains from the bottom?

    Much appreciate your help.

  • calistoga_al ca 15 usda 9
    10 years ago

    We can only guess what your potting mix is made of, but the guess is too much peat and too fine a particle size. If you do not water enough to flush some water from your drain holes, you have no chance of removing excess fertilizer minerals from your container and you will in time notice your foliage turning brown around the edges. Mixing perlite into your mix will help a little, sand or vermiculite will tend to make it worse. You should be able to make your own mix, but it will take some effort and time, but it will be worth it for any long time container plantings. Al

  • saoodhashim
    Original Author
    10 years ago

    Thanks Al

    Then what should I do. How to make a a good potting mix? I hope I find the material over here. The material for gritty mix

    Pine or fir bark in 1/8 - 3/8" size (no fines)
    Screened Turface MVP
    Crushed granite (Gran-I-Grit, in grower size) or #2 cherrystone
    gypsum

    I don't know where will I find these things in Saudi Arabia.

    I could only find peat moss, perlite, vermiculite and composted cow manure in the local market and ofcourse sand. I could also find granulated NPK pellets and liquid fertilizer (nitrogen and CaCl content only)

    What can I do with my limitations?

    Saood

  • meyermike_1micha
    10 years ago

    Hi Saood....

    Once you read those threads that Al wrote you can begin to understand the concepts of the mixes we use and why we use them

    You can apply these concept of this to your limitation in ingredients..

    LIke maybe using perlite, a small amount of peat and some very coarse sand will be a very fast and good draining mix? Let us know what you come up with that is very course, fast draining, holds moisture, and provides oxygen to the roots.
    A mix that holds it's structure and one that allows you to water more often without fear of root rot.

    You do have ingredients that will allow you to be a mix much better than bagged soils and very fine particle mixes..

    Nice to meet you and good luck

    MIke

  • meyermike_1micha
    10 years ago

    Hi Saood....

    Once you read those threads that Al wrote you can begin to understand the concepts of the mixes we use and why we use them

    You can apply these concept of this to your limitation in ingredients..

    LIke maybe using perlite, a small amount of peat and some very coarse sand will be a very fast and good draining mix? Let us know what you come up with that is very course, fast draining, holds moisture, and provides oxygen to the roots.
    A mix that holds it's structure and one that allows you to water more often without fear of root rot.

    You do have ingredients that will allow you to be a mix much better than bagged soils and very fine particle mixes..

    Nice to meet you and good luck

    MIke

  • saoodhashim
    Original Author
    10 years ago

    Thanks Mike and nice to meet you too.

    Castiloga recommended that mixing perlite into the potting mix that I already have will help albeit a little. Should I start off with this?

    As for the sand that I found available at the local garden shop was the red type - looking like the builder sand - but it was not coarse enough (let alone very coarse). Is there some sort of measure to determine how much coarse the sand should be for potting mix purposes? I have found a picture of the red sand from the internet and thought this might help you in assessing what I am referring to.

    Also I found a very huge supply of tiny gravel (around 5mm) just lying scattered besides my apartment building in quite a large quantity. Can that be used for any purpose? By appropriately mixing it with the potting soil or sand etc? Will this be helpful in water flow and aeration?

    O and btw, the potting soil that I will now be using (my fourth try) is on the link provided below - has details about what fertlizer and PH it has. It also says it has 125% water retention ability!!

    Thanks again.

    Here is a link that might be useful: Al Bustan Potting Soil.

    This post was edited by saood on Wed, Oct 9, 13 at 2:51

  • calistoga_al ca 15 usda 9
    10 years ago

    saood, I would feel better about your new mix if it said what the organic matter is made out of. Peat is organic, so is fir or pine bark. From the water retention figure, it looks like it must be peat that they using. You really need a bark based mix for best results. The object is not MORE water retention, but more AIR in the mix. If your only source for bark is decorative, far too large for your use think about ways to grind it smaller and then screen it to the size you want. I live in the woods with large amounts of fir trees dead on the ground, with lots of bark available in large slabs. I run it trough my chipper/shredder and then screen to size. Al

  • TheMasterGardener1
    10 years ago

    saood,

    How big are your containers and what are they made of? If they are normal sized and plastic you can easily just tip or lift the pots to see when they need water.If they are "paper" light then they need water. This is the best way to be sure. Also,you can wait until your plants wilt to show they need water.Plants grow fast when they are allowed to dry out in between watering. This year i just got done harvesting a boatload of produce all grown in containers using potting soil.

  • meyermike_1micha
    10 years ago

    Yes, I would use the perlite as a start....

    I would loose that sand since it is way too fine..

    Can you collect some of those pebbles you spoke of and take a close up pic of them?

    You kind of want your ingredients uniform in size...
    Bark is also great if you have access, but I think you said you did not...

    That mix you linked us to would only be a tiny fraction of any mix for any of mine...

    For example...A well draining mix would sound like this..

    5 parts perlite and one part of the mix.
    or
    1 part perlite and one part of those tiny coarse pebbles if good, and one part potting soil

    You knd of get my examples, right?

    You can create any kind of mix although not exactly what some of us have access too with the stuff you do and it can be fun if you understand the concepts of very porous mixes...
    Just make sure what you make holds moisture well but allows you to water frequently without over watering, and one that allows your roots to breathe. One that holds it's structure well..

    This post was edited by meyermike_1micha on Wed, Oct 9, 13 at 18:27

  • saoodhashim
    Original Author
    10 years ago

    Again, Sorry for repeating. Just reconfirming

    You are saying the the Al Bustan Potting Soil should be 1 part along with 5 parts of perlite??? Really? Is it a mistake? It sounds too much for perlite and too less of the potting soil?

    Those tiny pebbles - I realized they may soon settle down after after a few waterings. But I will still try it out. May be they could work :)

    And loosening that Sand? What does that mean? How do you do that?

    Thanks Mike.

  • meyermike_1micha
    10 years ago

    Hi Saood..I forget that our launguages have different meanings......Soory about that..

    What I meant was not to use the sand....

    I was giving you an example of what a porous mix can be...I live in a climate where I can use that much perlite with just a little bit of that mix...

    Also I am not sure if you realize that perlite can hold moisture..It can..More than you may think.

    That is what I would do.....

    Gievn how hot your climate is you could try so,etning that holds more moisture but still encouarges good root growth....

    Hav eyou considered using half and half? Half perlite and half that mix...Try it..If it hold moisture well without clogging up or staying wet too long....It might work..

    You only have limited resources from what I see but you can make them work...Not sure if you live near a forest, but I assume desert?
    Try to mix ingredients together with what you have that will create a great mix for you using Al's writings as a guide..Use the 5.1.1 and gritty mix as guides to build your own mixes...

    Hope this helps...

    MIke

  • TheMasterGardener1
    10 years ago

    That is good advice Mike.Go 50/50 potting mix perlite.

  • saoodhashim
    Original Author
    10 years ago

    I have been noticing that watering requirement for peppers is quote less than tomatoes. And that of tomatoes is less than cucumbers. Cucumbers seem to dry out quite quickly even in 100% fine peat based potting soil.

    I was thinking of have 50:50 for peppers and reducing it to 40:60 for tomatoes and 25:75 for cucumbers. Does this sound ok?