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deneb_gw

container vs. self-watering container mix

17 years ago

The only potting mixes I've seen specifically designed for self-watering containers are mail order and quite expensive. I would like to figure out what I can purchase (and possibly amend, but with what?) to use at less expense and hassle. I know the recipe for Mel's Mix, but my container garden is not nearly large enough to use even the smallest batch I could make if I bought all the multiple types of compost as he recommends.

I know that having any moisture-retaining crystals or other mechanisms is right out. But what else? More peat? Less peat? More perlite? Is coir ok as a replacement for the peat, or does its higher water retention and quicker breakdown cause trouble for self-watering containers?

Comments (22)

  • 17 years ago

    The potting mix doesn't need to be designed for SWC. Most any peat based potting mix such as the regular Miracle Grow mix works fine.

    Some choose to make their own mix based on pine bark 'fines' (small pieces, preferably partially composted) for better aeration while stick wicking well.

  • 17 years ago

    jag- what do you mean by stick wicking well, is that just another term for wicking?

    Damon

  • 17 years ago

    Sorry, typo. Meant to write 'still wicking well'.

  • 17 years ago

    Hi, I have a self watering container. Want to grow strawberries in the container. I'm using 5 gallon buckets. Any suggestions on how to make my own container mix. I have about 5 buckets to fill so I'm trying to save all the money I can on the soil. Thanks

  • 17 years ago

    You want something similar to this. Specifically you want the 5-1-1 mix.

    Alternately you could pick up a couple bags of the pine bark fines (usually sold as soil conditioner or aged pine bark or similar names) and a bag of either Turface MVP (check landscape supply stores) or Napa Auto Parts Floor Dry. Mix 3-4 parts bark to 1 part Turface or Floor Dry and skip the peat altogether.

    Regardless of which way you go add dolomitic lime at the rate of 1/4 cup-1/2 cup per cubic foot of mix (7.5 gallons) to balance the pH and add calcium and magnesium.

    It is important that the bark be small pieces with some of it partially composted. If it is more fresh then add peat to the mix.

  • 17 years ago

    justaguy,
    How do your self-watering containers work for vegetables compared to your standard containers or raised beds? For example, do you see more vigorous growth in one method or more production for vegetables like tomatoes, corn, or potatoes? Please include your fertilizer choice with that answer. By the way I was reading one of your old posts on Gardeners Supply and EarthBox self-watering containers this morning. Good read!

  • 17 years ago

    I would say they work about the same, deep roots. There is no question I get better pepper yields from containers than the raised beds though., I think it is likely that the containers provide more warmth which is making the difference.

    On balance though I wouldn't say one works better than the other. There are minor differences, but if I could grow veggies only one way it would probably be SWC.

    What I used for fertilizer last year and will again this year is Foliage Pro 9-3-6 and Pro Tekt 0-0-3. Peas, beans, cukes and most of the early season stuff I just use FP on as a 3:1:2 ratio suits them.

    Tomatos, peppers, onions, eggplant use nutes in a 3:1:3 ratio so I add the PT to increase potassium for those.

    This year I will try some watermelons in SWC and for those I will likely alter the ratio to 3:1:4

  • 17 years ago

    justaguy2,
    Thank you for your response! After giving up my 45' x 90' conventional garden for twin 2.5' x 12' raised beds and an in-ground, plastic-sheet mulched, melon patch, I am once again looking at revisions.

    After seeing 32 mature and producing corn stalks in two plastic SWC containers, I have got to think twice about how much material and amendments that I use in my raised beds. Of course, the intensive planting that the SWC supports will help avoid looking like a tupperware convention in my yard.

    I lean toward growing tomatoes, cucumbers, summer bush squash, watermelon, muskmelon, sweet corn, onions, radishes, bell peppers, and hot peppers. I am thinking of using couple larger SWC's with mixed plantings.

    I see that you are using liquid fertilizers in lieu of the simpler granular fertilizer that EarthBox recommends. Have you found the fertilizer strip, plastic cover, and bottom up wick watering is that inferior to top down watering with liquid fertilizers? What have you noticed in comparison?

    Also, I would need to bring my SWC's into the garage for winter to avoid water accumulation and freezing that might break something. With the weight of EarthBoxes, have you developed a strategy for wrestling the containers?

    The EarthBox Automated Watering System certainly looks like a winner, considering acceptance of the cost. Since there is no way to overwater the EarthBox style planters, I have even considered using a timer and garden hose to add water without worrying about the excess water. The excess water could even be diverted to gravity feed some in-ground plantings. Are you hand-watering everything?

  • 17 years ago

    Have you found the fertilizer strip, plastic cover, and bottom up wick watering is that inferior to top down watering with liquid fertilizers?

    No, the granular along with the cover works fine. I do what I do simply because it's my preference, not that the 'normal' way doesn't work or is inferior. I enjoy the control I have over when and how much nutrients are being supplied. I don't top water/fertilize though, I add the FP and PT to the reservoir itself. Also, I would need to bring my SWC's into the garage for winter to avoid water accumulation and freezing that might break something. With the weight of EarthBoxes, have you developed a strategy for wrestling the containers?

    I just tip them to empty any remaining water and then dump the contents into a wheel barrow. The containers can then be stacked in the shed. The mix itself goes into plastic garbage cans or the raised beds if I won't be reusing it. Are you hand-watering everything?

    Yes, I hand/hose water all the EBs. The fill tube on the EB is easy to just stick the hose into and let it run until I see some overflow.

    I think you will really enjoy using SWCs and you will be pleasantly surprised just how much can be grown in such a small space.

    To date the largest plant I grew was an Atlantic Giant pumpkin. It did very well. I didn't end up with any record breaking pumpkin, but for it being the first time I ever tried growing a large pumpkin and doing it in a SWC and getting the fertilizer wrong in the first part of the season followed by a vine killing frost a month earlier than normal I was pretty pleased. The vine was around 25' long when I chopped it off to 20' as it was taking up so much space.

    I tried again last year and my dogs chewed up the vine...Grrr. The dogs are still both under 1 year old so I am quite nervous about this season. Oh well, what can I do.

  • 17 years ago

    justaguy2,
    Thanks for the wealth of details! Ahhh..., fertilizer in the water. You must be an artist to avoid issues with EC, pH, salt regulation, nutrient level control, and dissolved solids. This makes me curious how much you add, how often, and whether you flush out the water chamber periodically.

    Appreciate the 'been there/done that' advice on over-wintering the containers. I have heard the containers are 130 pounds wet from one source, which sounds more like a permanent outdoor fixture. I previously considered mounting a couple SWC's to a wagon and pulling them in and out of the garage.

    About watering, I have enough fun hand-watering my indoor containers, which are up to 22" diameter. Somehow, I think a form of automation will be helpful, especially should I set some of these SWC for my elderly neighbors who have mobility issues.

    Regarding the Atlantic Giant pumpkins, I have grown them in ground. Dumped a hay wagon of composted manure on a 25' x 50' grow patch with soaker hoses. This was the summer when the vines took over the yard. Best seeds come from competition clubs. I used to be an IPGA member. Off the shelf AG seeds usually do not live up to the name. Do know a 700 pound plus AG was grown in a tiny area once. Sounds like your dogs will give you fits for awhile though, which is okay because they spared you the dreaded squash vine borer lament.

    With enough information to make a foray into SWC grow boxes, I am now looking at making choices about which hardware to purchase. Maybe I will have to take my Square Foot Garden lumber and Mel's Mix from the basement and convert it by putting a pond liner in the frame, rigging an aeration screen to suspend the soil, and drilling a drain. That would be an interesting endeavor.

    EarthBox

    Tomato Success Kit

    Garden Patch Grow Box

    Self-Watering Whiskey Barrel

    Self-Watering Window Box

    Making Your Own SWC

  • 17 years ago

    Ahhh..., fertilizer in the water. You must be an artist to avoid issues with EC, pH, salt regulation, nutrient level control, and dissolved solids. This makes me curious how much you add, how often, and whether you flush out the water chamber periodically.

    LOL, believe me, it isn't that difficult!

    I generally use 1/4th strength as a baseline and adjust upward to 1/2 strength as plants grow and temps warm. For some things like the AG pumpkin I go full strength once per week with no issues, in fact I was considering increasing the frequency for those. I do actually have seed from 800+ lb pumpkins, though the seed I have now is from what I saved from the first one. I made baked pumpkin seeds from the rest. They weren't particularly good ;) Lots of good folks in Wisconsin (clubs) more than willing to send free seed too.

    Anyway, I do flush the reservoir from time to time, but I am not regular or disciplined about it. I am only growing stuff in them that lives 3-5 months and they get flushed, cleaned before another season. Flushing is mostly accomplished by leaving the hose in the fill tube while I am off looking at something else and coming back to find it overfilled ;) I have heard the containers are 130 pounds wet from one source

    Not for an EB. Some of the homemade units with very large water reservoirs may weigh that much filled with water, but otherwise they aren't that bad. I am guesstimating a filled EB to be around 70lbs or so. Of course I don't try to move them when filled with water.

    I will tell you the same thing I tell anyone who asks about which way to go with SWC. Get a commercial EB or 5 and just have fun with them for a year. After that you will know what, if any changes you want to make. Nothing at all wrong with DIY. Had I started off with the GS box instead of EBs I would likely be making my own now too as I find the design has a couple annoying issues mostly related to filling them up.

    If I lived in a hot arid climate where I had to top off the reservoir multiple times daily I would also likely be making my own to get a larger reservoir or using some sort of automated irrigation system.

    As it is EBs suit me just fine.

    I don't have any of the Garden Patch boxes. I used to hear they were made more cheaply, but I haven't heard that lately. I had thought they used to be $19.99 as well, but I see they are now $29.99, same as an EB.

  • 17 years ago

    Justaguy is really my kind of guy except I am more "frugal". I am retired and really enjoy DIY things including building a number of kit airplanes. Flew one from Fl to Alaska in 01, oh well I am off topic.

    I started trying to garden the first time late last fall. Put some seeds in real soil I dug out from under palmettos here in the yard and contained them in 16 in sq concrete column blocks left over from my building the airplane hangar.

    {{gwi:22889}}

    From there I graduated to a box made from scrap stuff but still with real soil and put 6 brandywines and beets and radish in it.

    {{gwi:22891}}

    And from there I started doing 5 gal bucket SWC's with mix "soil" in it. Here a bigbeef which has Ed Smith mix which is 45% cowcompost (HD $1.60 a bag),45% peat, and 10% perlite. This is very inexpensive if you get the perlite in 4 ft3 bag for less than $10. There are 2 cups of 6 6 6 fertilizer ring around the top plus lime mixed with it.

    {{gwi:22892}}

    Am currently trying to run a controlled test of the above mix and a mix of 5 pinefines, 1 peat, and 1 perlite. Both of these have 1/4 cup of 14 14 14 nutricote CRF mixed with the soil. Gave the pinefines mix a shot of liquid MG since the CRF will not kick in immediately. The cow compost has a significantly larger diameter stalk and greener healthier looking leaves, but too early to judge yet. The cow mix is on the right in the pic.

    {{gwi:22893}}

    Watering each individually with rain water poured from a pail through a funnel became too time consuming, plus I'm running out of rain water. It is quick to water with a hose and well water. I am trying to put SWC in series and use my drip timed water to keep the reservoirs topped so that when I'm not here do not have to depend on neighbors. By the way the large big beef plant consumes over 2 gal per day !

    {{gwi:21507}}

    Sorry to get so long winded on my first "container" post :>)

    bernie

  • 17 years ago

    Interesting methodology, Bernie. Just as an FYI, you are unlikely to be satisfied with the performance of your tomatos that are getting only the nutricote. I would recommend using the MG soluble regularly and ignoring the presence of the nutricote.

    Just think of the nutricote as insurance in case you forget to fertilize.

    What is your growing climate like in terms of temps and humidity?

  • 17 years ago

    Justaguy, Tom Mobley has a had unbelievable success with just 14 14 14 in his pot n pot method. I am totally new at this business, my dad who just past away this year at 99 always had a large veggie garden in NC, but I was never interested until now at 72 ! I have put some MG in the water once they started blooming, but this first big beef is unbelievable (seems to be my favorite word this morning :>)).

    Our weather here is very subtropical, I have two very large mango trees that people said would not survive this far north and west (away from the Atlantic and gulf stream), but put them on the South side of my 12 cbs wall of the hangar and they have done extremely well.

    People keep tomatoes producing here from fall until June when it apparently is so humid that they fail to set new fruit. Typical day high here summer is 92 and 90% humidity and 70 low at night. Lots of rain in summer, we've had zip where we're located here west of port st lucie this winter and spring.

    Sorry about how dark the pictures turned out and with my palmetto background it is really hard to see how large the first bigbeef is in the bucket. Will try again to make a picture.

    bernie

  • 17 years ago

    Here is a better photo of the first SWC bigbeef which is now over 60 in tall. It was transplanted from a HD bigbeef less than 2 months ago. The "soil" in this container has to be less than 3.5 gal, yet it supports this large plant. Amazes me, don't know about you experienced container growers :>)

    {{gwi:14782}}

  • 17 years ago

    Bernie, thanks for posting pictures and please keep us updated on your experiments.

    Deneb, you donÂt need to amend soilless mix with anything when using Earthboxes (except dolomite and fertilizer). Nor do you have to mix your own mix unless you want to , storebought mixes are fine. I receive the Earthbox newsletter and they had an article on potting mixes for the EB. I found this webpage with the same article written by Earthbox people. SEE LINK

    You could also add Lamberts Potting Mix to the list available at Home Depot here in Florida.

    Here is a link that might be useful: Earthbox recommendations for potting MIX

  • 17 years ago

    Oops, that list of theirs start out with a confusing recommendation. Miracle Gro Soil should still be a soilless one that does not contain soil. I thought MG called their soilless mix by the name MIX not SOIL now.

    You can check out their products on their website to be sure you got the right one. And one of their organic soil products , according to the info on the bag, should not be used in containers. Clear as mud now, right?

  • 17 years ago

    Miracle Grow is dominating the market. I went to Home Depot and they are not carrying Pro-Mix. Seems Home Depot, Lowe's, and Wal-Mart are all Miracle Grow potting mix dealers now. Hope this works well in the typical setup with my new EarthBox.

  • 17 years ago

    We're being forced to try the self-watering container method. We have incredibly sandy soil and it just dries out too quickly. We came across Edward C. Smith's "Incredible Vegetables from Self-Watering Containers" and are trying to make our own containers since they are so expensive. And, we're making our own mix. If you tried to do a full garden and buy all those containers and mix for them, it would cost a fortune.

    Here is a link that might be useful: Organic Garden Works

  • 17 years ago

    Diggerjones, Ed Smith's book is a good starting place, but is somewhat dated compared to the gardenweb folks like Tapla and Justaguy info.
    Here is a pdf on DIY 5 gal buckets that I find inexpensive and work great. Get your buckets free from burgerking (pickle) or pastry buckets from bakeries.

    http://www.wisefarmer.com/growbox/Homemade_Earthbox.pdf

    Look about page 18 to see 5 gal buckets.

    bernie

  • 17 years ago

    Somewhere on the web I wrote a review of Ed Smith's book. I know it's on Amazon, but I thought I posted it on GW somewhere too. Anyway, I really like some of Smith's previous books on soil growing, but was not even remotely impressed with his SWC book.

    The primary reason is that Ed makes the same mistake most ground growers do when transitioning to containers. They assume it's basically the same thing.

    The end result is folks want to incorporate soil, compost and other stuff that is of too fine a particle size into their growing mix. They also get hung up on the idea of the growing media being the source of plant nutrition.

    The end result, particularly in SWC is a very soggy, wet growing media that some veggies will adapt to OK, but many won't.

    With respect to Ed's past work, I recommend skipping his SWC methods.

  • 17 years ago

    I agree with justaguy. I did NOT learn a thing after reading it that would help growers who use SWC designs. This message board has more important content than ANY book you will ever read on Container growing.

    Raybo