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gardenrod

Effect of containers on underlying soil

gardenrod
13 years ago

Being space limited, after I harvest greens from a raised bed, I move large containers containing peppers or tomatoes onto the raised bed.

Does anyone know how the drainage from the pots impacts the soil beneath?

Would this cause a buildup of salts and over fertilize the raised bed?

If this is a problem, how could it be corrected?

I know this compacts the soil, but I do double-dig the beds every year.

Ronz

Comments (14)

  • jodik_gw
    13 years ago

    I'm sure tapla (Al) will be along shortly to give you the information you seek. In the meantime, I want to mention that I do the same thing, occasionally.

    There are 4 raised beds, about 8'x 8' square, that I grow a vegetable garden in every year. After harvesting the early crops, I sometimes utilize the empty bed space to hold some large patio pots of other plants.

    I notice no ill effects, but that could be because I re-dig and amend the raised beds every spring before planting, and I think the amount of rain we get, plus the watering I do, adequately flush anything unwanted from the soil in the raised beds.

    And now, I await Al and his expertise...

  • tapla (mid-Michigan, USDA z5b-6a)
    13 years ago

    I don't see it as being an issue that you would even notice. Spring rains or a good soaking with the hose should flush the soil quite well. It sort of matters too, how much mineral content is in the raised bed soil. Soils with higher mineral hold nutrients better.

    Also, having some of the alts from your container isn't necessarily a bad thing - especially if your RB soil has a high organic presence. I know that fertilizer isn't plant food - that plants make their own food, but for the sake of what I'm about to offer, let me say that "Plant foods are salts. Salts are what plants 'eat' at the cellular level, and they don't care if their N P K CA MG .... come from breaking down organic matter or from the effluent from the containers you have resting on the bed."

    If it was me in your position, I wouldn't think twice about it.

    That was a nice thing to say, Jodi! No wonder we get along so well. Lol

    Have a good day, you guys!

    Al

  • gardenrod
    Original Author
    13 years ago

    Many thanks to both of you.
    Another question-
    I appreciate all the good advice I've found on this forum, but am somewhat overwhelmed by reading so much about container soils. This question may be answered in some of the discussions, BUT-
    I've always placed a layer of rock particles at the bottom of my containers. I have learned from Al's posts that this does not help drainage, because it prevents the uptake of moisture and nutriants from the ground soil (right ?).
    I'm going to use a couple of 32 Gallon containers with the soil-less container mix this year without the rock layer to compare with results from my previous approach.
    1- My old method - replace about half of the previous years container soil with a mix of perlite, peat moss and cattle manure, then mix all the soil with the new ingrediants.
    2- Use the 5-1-1 soil-less approach with no rock layer.

    NOW- the question (finally)-

    What is the best way to set up the container-
    On bare earth?
    On tilled soil?
    On a bed of mulch?
    On a raised table?
    I figure that if I'm going to change my gardening habits, I might as well go all the way to see what I need to do in the future.
    Too wordy? - I don't have many gardening years left, so want to find out how to get the best results I can.

  • tapla (mid-Michigan, USDA z5b-6a)
    13 years ago

    The soil you described will be very water-retentive - almost certainly too water retentive to allow you to get the best from your plants because it will remain soggy for so long. The best way to treat your set-up would be to partially bury the container. To make this effective, you only need to make sure the soil at the drain holes is in direct contact with the soil beneath. This turns your 'container' into a 'mini raised bed', hydrologically speaking, and changes the way water will behave in the container. Instead of the excess (perched) water your soil is sure to support remaining in the container, the earth will act as a giant wick and 'pull' the excess water out of the container and into the ground below.

    You can grow most effectively in conventional containers with soils that are well-aerated and free-draining, and that will remain that way for the expected life of the planting. You can read more about how water behaves in soils at the link below. Understanding the principle the thread presents is a very important part in helping you pull everything together as you move forward in your container gardening adventures. ;o) The thread pushes a concept, or a way of looking at container culture that separates it from garden culture. The soil recipes are simply a way to help you conceptualize and a good starting point should the information cause you to stand and take notice.

    Best luck.

    Al

    Here is a link that might be useful: More info here

  • gardenrod
    Original Author
    13 years ago

    OOOPs-
    I forgot to mention that I currently place my containers on bricks on top of cypress mulch.
    Ronz

  • tapla (mid-Michigan, USDA z5b-6a)
    13 years ago

    It's your call - I just do my best to lay out the science in an effort to give you what you need to make your choices. No matter what though, I wish you best success. ;o)

    Al

  • gardenrod
    Original Author
    13 years ago

    That is what I needed to know.
    Thanks,
    Ronz

  • jodik_gw
    13 years ago

    There are a few key elements of container growing I wish I had learned decades ago... and the very first key element is that container growing is exceedingly different than growing in the ground!

    I wish that the gardening world was devoid of fallacy and old wives tales, but this isn't the case. There's no such thing as a "green thumb", per se... it's all simple knowledge. There's no luck involved, either... unless we're talking about the weather. Successful growing is all about learning the basics of plant science, learning the relationship between the factors that make up a container planting, and applying that knowledge along with a little effort.

    Once you learn the basics, and you add a little logical thinking, it all becomes so clear, so easy! I wish I'd met Al years ago! I guess you can tell I'm a convert of the "gritty mix" variety! :-)

    Regardless of the type of growing you choose to do, being armed with the basics in plant/growing knowledge can really mean the difference between mediocre and fantastic results!

    Anyone that says they lack a green thumb simply hasn't learned the basic science of plant behavior. It's not complicated, at all. I once thought so, but I've since learned differently. I now understand the relationship between the factors that make up a potted planting, and it's all due to the article Al has written in "Container Soils - Water Movement & Retention", which is its own thread that usually stays on page 1, here.

    Happy Gardening!

  • calistoga_al ca 15 usda 9
    13 years ago

    I hate to find any disagreement with Al(tapla)because I risk sounding stupid. When I have containers in direct contact with the ground for any length of time, the roots grow into the ground and when I try and move the container I must first insert a blade under the pot to cut off the roots. I have one at the moment on paving that has grown into the ground. Al

  • jodik_gw
    13 years ago

    That may depend upon length of growing season, and type of plant... I haven't had issues with roots growing into my raised beds from the pots above, but I also haven't grown large or overly vigorous growers there, either.

    It could happen... I think it just depends on a few variables.

  • tapla (mid-Michigan, USDA z5b-6a)
    13 years ago

    That's a good thing to mention, Al, because it happens to people all the time. LOTS of reports of this from people over on the fig forum. It's like, "Dam- Darn! I set it down here 2 months ago & when I went to move it into the garage for the winter, it had 2" thick roots growing out of every drain hole - had to get a crane to move it" - or something similar. ;o)

    I got the impression that what Ron was doing was a temporary thing, but if it's not, be sure to heed Al's good advice. Lifting the containers & rotating them 90* every couple of weeks, or lifting & pruning off the wayward roots are viable solutions.

    Remember too, if you don't mind dealing with those anchor roots the plant is sending down into the soil beneath the container, they're going to add a LOT to growth and likely improve o/a vitality.

    Good catch, Al! ...... always good to have you watching over us.

    In case everyone doesn't know - Al has a LOT of growing experience and has made a lot of wonderfully helpful contributions to this (and I'm sure, other) forum(s) in the time I've known him. If I was a drinking man, I'd love to sit and share a 6-pack with him while I picked his brain, because I'm sure I could learn a lot from him.

    Al

  • gardenrod
    Original Author
    13 years ago

    Al-
    I grow only tomatoes and hot peppers in containers during the Spring, then spinach and lettuce during the early Winter.
    The reason I am so intersted in your mix is that my ground crops always outperform my container plants, but I feel that I can do better.
    I bring in about 50 bags of topsoil, 10 bags of cow manure, 2- 2 cubic ft bags of perlite, and a couple of 4 cubic ft bags of peat moss every year, and, as you surmized, none of it is very good for next year's use.
    When finished, I do mix it in with my garden soil, but I keep the soil the tomatoes grow in separate from the pepper soil.
    I am really anxious to start my seeds, and hope to be able to resist until late February to get started.
    I look forward to trying your approach, and hope you will be there if and when I need more help.
    Ronz

  • jodik_gw
    13 years ago

    Depending on the size and height of the containers, I wouldn't worry so much about pepper plants sending down humongous anchor roots... but tomatoes might be another story!

    I once grew a single yellow pear tomato plant in an area with extremely poor clay/gravel soil. By the end of the growing season, I swear I needed a saw to get rid of the trunk, and you should have seen the root system! I can only imagine what might have happened if that had been grown in a large container with decent soil!

    Calistoga Al is a heck of a respected gardener, and I'd love to sit and converse with him... actually, with both Als! Talk about filling the cup of knowledge to its brim! :-)

  • tapla (mid-Michigan, USDA z5b-6a)
    13 years ago

    I'll be around when you need help, Ron - as will a host of other helpful container gardeners with a good grasp of how to squeeze the most out of a soil and your plants.

    I hope you had some idea before now, how well-regarded you are, Al. ;o)

    Wishing all you guys a good day!

    Al