Container Toms: Reusing this year's mix?

11 years ago

I'm growing quite a few toms in containers this year for the first time and have put a fair amount of money into the potting mix I use. I'm wondering if up here in Minnesota I could get away with reusing at least some of the mix next year. My thought was to devote one of three sections of my huge composting area to the mix, putting down a layer of landscape cloth at the base. Is it utopian to think our severe cold would help render the mix more acceptable for use next spring? The alternative is to dump it into the compost heap or on the gardens at the end of this season and just start over for the containers next year. But it would be nice to save some money as well. Any advice or experience appreciated. TIA, Gary.

Sort by:Oldest

Comments (14)

missingtheobvious
11 years ago
There have been threads about re-using some container mix the following year.

Here's a link with a link in the last post.
http://forums.gardenweb.com/forums/load/tomato/msg0212484525931.html

I don't remember having seen any explanation of how people store used mix over the winter. Maybe in one of those threads (which are from posts all across GW, not simply in the Tomato forum)....
digdirt2
11 years ago
As I posted on another question about this -

"Reusing it gets mixed opinions. Some swear never! Some do it all the time. So all I can tell you is that I do. I dump all the containers out onto a big tarp, spread it out in the sun with a rake to dry well, then I mix in about 1/3 new mix and some fresh pelleted fertilizers with it. After cleaning all the containers well I refill the containers and go from there. After the 3rd year the old goes into the garden and I start with new in the containers. Never had any problems with this method."

I need to add to that info that it all depends on what mix you use in the first place. Some break down much faster than others. I only use ProMix BX in my containers.

You'll find much more info about this question over on the Container Gardening forum as that is their focus.

Dave
Related Discussions
Boiling water to sterilize & re-use potting mix?
Q
Comments (22)
It's pine bark, but it's hard to say by the picture if the size of the bark is appropriate. It looks like it's quite large. If you read the link Jodi left for you upthread, you probably realize that particle size and distribution is very important to how a container soil performs. Here is something I wrote to illustrate the importance of particle size/distribution: Obviously, I think the grower's soil choice when establishing a planting for the long term is the most important decision he/she will make. There is no question that the roots are the heart of the plant, and plant vitality is inextricably linked in a hard lock-up with root vitality. In order to get the best from your plants, you absolutely must have happy roots. If you start with a water-retentive medium, you cannot improve it's aeration or drainage characteristics by adding larger particulates. Sand, perlite, Turface, calcined DE ...... none of them will work. To visualize why sand and perlite can't change drainage/aeration, think of how well a pot full of BBs would drain (perlite), then think of how poorly a pot full of pudding would drain (bagged soil). Even mixing the pudding and perlite/BBs together 1:1 in a third pot yields a mix that retains the drainage characteristics and PWT height of the pudding. It's only after the perlite become the largest fraction of the mix (60-75%) that drainage & PWT height begins to improve. At that point, you're growing in perlite amended with a little potting soil. You cannot add coarse material to fine material and improve drainage or the ht of the PWT. Use the same example as above & replace the pudding with play sand or peat moss - same results. The benefit in adding perlite to heavy soils doesn't come from the fact that they drain better. The fine peat or pudding particles simply 'fill in' around the perlite, so drainage & the ht of the PWT remains the same. All perlite does in heavy soils is occupy space that would otherwise be full of water. Perlite simply reduces the amount of water a soil is capable of holding because it is not internally porous. IOW - all it does is take up space. If you want to profit from a soil that offers superior drainage and aeration, you need to build it into the soil from the start, by ensuring that the soil is primarily comprised of particles much larger than those in peat/compost/coir, which is why the recipes I suggest as starting points all direct readers to START with the foremost fraction of the soil being large particles, to ensure excellent aeration. From there, if you choose, you can add an appropriate volume of finer particles to increase water retention. You do not have that option with a soil that is already extremely water-retentive right out of the bag. I fully understand that many are happy with the results they get when using commercially prepared soils, and I'm not trying to get anyone to change anything. My intent is to make sure that those who are having trouble with issues related to soil, understand why the issues occur, that there are options, and what they are. Many use their current potting soils (like MG or used soils as a smaller fraction of a new media they put together specifically to improve drainage & aeration, so yes - you CAN use some of the soil you have as a fraction of a new soil, but keep in mind that you aren't going to rid yourself of the drainage/aeration and high PWT issues problems unless your soil is weighted heavily toward larger particles than your current soil is currently comprised of. When you add a little extra perlite and/or pine bark to a peat-based soil, you don't change the drainage characteristics, the height of the PWT, or aeration. You DO decrease the total volume of water the soil CAN hold, and that IS a plus, but that's about all you really accomplish. Add a LOT of (appropriate size) bark and perlite = job done. The physics of how water behaves in container soils doesn't change because someone might assure you it does. As surely as the cow is barred from jumping over the moon by the law of gravity, soils are bound by physical laws to exhibit rather specific and predictable characteristics based on their particle size and distribution (enter the pudding analogy into evidence). If you choose not to go with a soil that has a considerable fraction of larger particles, there are ways to help you deal with excess water retention when it occurs. There is a lot of good information about dealing with water retention if you follow the embedded link. When you get to where you're deciding about how you want to proceed with your soil, we can talk more specifically about tailoring a plan that best supports your methodology. Take care. Al
...See More
Reusing soil mix, newb needs help.
Q
Comments (3)
Thank you for the advice justaguy. I will probably amend with a very small amount of lime, small amount of cow manure, mushroom compost, worm castings, compost, and marine cuisine. I'd imagine there should be a considerable amount of bacteria and fungi in the soil, so hopefully as long as the pH is relatively close it should be alright. I picked up a Better Boy, Giant, Arkansas Traveler, Grape Tomato, and Sweet 100. 2 slicing cucumber plants. 1 Jalapeno pepper, 1 Italian pepper, and 1 Salsa pepper. 1 Squash plant/vine. Rosemary, and 2 Thai Basil (I had them last year and they smell delicious. kind of sweet black licorice), and parsley. Funny Story. I made the mistake of purchasing strawberry plants 2 years ago( in my first year attempting a garden), not realizing how aggresively they attempt to spread themselves. I did my best to do them in last year by barely ever watering them. I accidentally overwintered them this past year, honestly. I put a white painter type tarp over 2 of my kiddie pools, 1 pool contained oregano, the other over the strawberries. I removed these tarps about a week and a half ago. Much to my surprise I had thriving oregano and strawberry plants that overwintered. The oregano has taken up more than half of the kiddie pool it resides in. The strawberry plants spread like wildfire and now occupy basically an entire kiddie pool. So may actually end up with some fresh strawberries froom the garden this year, as there are many berries on the various chutes in the pool (probably about 50 fruit right now, some very small, some relatively large.). I use 10 kiddie pools filled with this mix, and 4 box style planters to provide homes for my outdoor garden. Thanks for listening all. Any further input/comments are welcomed.
...See More
Reusing Container Mix
Q
Comments (13)
MeaWea, any decent potting mix is actually soiless. Most of them are mostly peat, coir, or peat-coir, with a smaller portion of perlite and/or bark fines. So don't worry about the guy who was flabbergasted at the idea of a soiless potting mix. Lots of soiless mix ingredients, including fines and coir, get "hydrophobic" if they are left to dry out. Turface can get that way as well. I've never had trouble with peat getting hydrophobic in a potting mix, as long as I wet it well before mixing it in and didn't let it get too dry in the pot. Compost in potting soil is not a good idea. It's great for conditioning soil - but the best container mixes are soiless. It's its own little microcosm, and when its healthy, it's just totally different than healthy soil-in-the-ground. Currently I'm trying a pumice-peat mix. My preferred potting soil was peat-vermiculite for about 30 years, but in the last 15 years, I've not been able to lay hands on the really coarse vermiculite, not even by special order. You don't even want to know what I've been using instead. Lets just say I made it work for me but it was far from ideal. I would not expect it to work in the desert environment to which I have recently moved without far more trouble than it is worth. Here, I can get pumice reasonably inexpensively and very easily. It has other properties that might make it useful in a desert environment. I don't know that it would be as useful in your climate, or whether you could find it all the way over on the other coast. If your potting medium is mostly peat, you can probably get away with using it for 2 or 3 years. However there are issues of sterilization as well as breakdown of components involved. I used to reuse potting mix for one season (eg 2 total seasons of use) and after that it went into the compost. I did not mix in new stuff with the "old" because that never seemed to accomplish anything noticeable. For houseplants, it went straight into the compost whenever I repotted. If you're going to try the 5-1-1 mix, try to find the coarsest perlite you can lay hands on. Home Depot carries some under the Thermorock label that is SUPPOSED to be coarse. People on these forums don't seem to like it, but at least it can be found almost anywhere across the country. Perlite, at least, is easy to stuff into several large plastic bags (I'd double layer them) - but no more than you can flatten out after tying it off so you can stuff it under your bed. I'm big on using wasted space. It's light weight so as long as you don't overfill the bag it'll be out of sight when you don't want it, but easy to get when you need it. Bark and peat - not so easily stored.
...See More
Earthworms in Reused Container Mix - Looming Disaster?
Q
Comments (2)
You shouldn't have to depend on soil fauna for aeration, it should be built into the soil and you should be sure that the soil is able to remain structurally sound enough to ensure that it will retain adequate aeration for the intended life of your planting. If it will not, you invite those several issues associated with a collapsed soil and you should be thinking seriously about replacing it and turning the old into garden/bed/compost pile. Also, it's best if you resign yourself to the idea that you, not the medium, is ultimately responsible for the plants' nutritional needs. There is nothing the earthworm can offer in containers that you cannot find in other organic or chemical products. In short, their contribution to a more rapid deterioration of a soil that is already well advanced in it's structural collapse is not something I would welcome. Cut/pasted from another of my posts: In my estimation, the only case to be made for reusing container soils is one of economics, and you'll never find me argue against making that decision. If you can't afford, you can't afford it. That said and setting economics aside, you might decide to reuse soil for reasons other than economical. Perhaps the effort involved with acquiring (or making your own) soil is something you might not wish to go through or be bothered with. In any case, it would be difficult to show that soils in a more advanced state of structural collapse can somehow be preferred to a soil that can be counted on to maintain its structure for the entire growth cycle. So, if the economic aspect is set aside, at some point you must decide that "my used soil is good enough" and that you're willing to accept whatever the results of that decision are. All soils are not created equal. The soils I grow in are usually pine bark based & collapse structurally at a much slower rate that peat based soils, yet I usually choose to turn them into the garden or give them over to a compost pile where they serve a better purpose than as a container soil after a year of service. Some plantings (like woody materials and some perennials) do pretty well the second year in the same bark-based soil, and with careful watering, I'm usually able to get them through a third year w/o root issues. Watering habits are an extremely important part of container gardening. Well structured soils that drain well are much more forgiving and certainly favor success on the part of the more inexperienced gardeners. As soils age, water retention increases and growing becomes increasingly difficult. If your (anyone's) excellence in watering skills allows you to grow in an aging medium, or if your decision that "good enough" is good enough for you, then it's (your decision) is good enough for me, too. The phrases "it works for me" or "I've done it this way for years w/o problems" is often offered up as good reason to continue the status quo, but there's not much substance there. I'm being called away now, but I'll leave with something I offered in reply on a recent thread: "... First, plants really aren't particular about what soil is made of. As long as you're willing to stand over your plant & water every 10 minutes, you can grow most plants perfectly well in a bucket of marbles. Mix a little of the proper fertilizers in the water & you're good to go. The plant has all it needs - water, nutrients, air in the root zone, and something to hold it in place. So, if we can grow in marbles, how can a soil fail? Our growing skills fail us more often than our soils fail. We often lack the experience or knowledge to recognize the shortcomings of our soils and to adjust for them. The lower our experience/knowledge levels are, the more nearly perfect should be the soils we grow in, but this is a catch 22 situation because hidden in the inexperience is the inability to even recognize differences between good and bad soil(s). Container soils fail when their structure fails. When we select soils with components that break down quickly or that are so small they find their way into and clog macro-pores, we begin our growing attempts under a handicap. I see anecdotes about reusing soils, even recommendations to do it all over these forums. I don't argue with the practice, but I (very) rarely do it, even when growing flowery annuals, meant only for a single season. Soils don't break down at an even rate. If you assign a soil a life of two years and imagine that the soil goes from perfect to unusable in that time, it's likely it would be fine for the first year, lose about 25% of its suitability in the first half of the second year, and lose the other 75% in the last half of the second year. This is an approximation & is only meant to illustrate the exponential rate at which soils collapse. Soils that are suitable for only a growing season show a similar rate of decline, but at an accelerated rate. When a used soil is mixed with fresh soil after a growing season, the old soil particles are in or about to begin a period of accelerated decay. I choose to turn them into the garden or they find their way to a compost pile. Unless the reasons are economical, I find it difficult to imagine why anyone would add garden soils to container soils. It destroys aeration and usually causes soils to retain too much water for too long. Sand (unless approaching the size of BB's), has the same effect. I don't use compost in soils because of the negative effect on aeration/drainage. The small amount of micro-nutrients provided by compost can be more efficiently added, organically or inorganically, via other vehicles. To boil this all down, a container soil fails when the inverse relationship between aeration/drainage goes awry. When aeration is reduced, soggy soil is the result, and trouble is in the making. Al
...See More
garystpaul
Original Author
11 years ago
Thanks a million, guys. A lot of reading there, but very helpful. I like the idea of spreading it out in the sun. Dave, could you specify the reference to "fresh pelleted fertilizers"? Many thanks, Gary.
garystpaul
Original Author
11 years ago
Thanks a million, guys. A lot of reading there, but very helpful. I like the idea of spreading it out in the sun. Dave, could you specify the reference to "fresh pelleted fertilizers"? Many thanks, Gary.
mewhee
11 years ago
Hi Gary -

I've got a relatively small tomato space as my garden takes up a very limited area by the pool filter/heating equipment - approximately 16 plants of which half are potted. Mixed in w/ the in-ground tomatoes are a fair amount of large adobe/clay pots on hardscape which each year are re-used after soil turnover and adding a modicum of new amendments with no problem in terms of production/disease and every plant is coming along just as hoped (knock on wood).

Next year as a preventive measure, I sure like Dave's method above and will give that a go.

Good luck in whatever you decide to do -

Will and the Furry Ones in the OC
digdirt2
11 years ago
could you specify the reference to "fresh pelleted fertilizers"

Osmocote or similar slo-release product. Mixed in well before refilling the containers. Then I use a good quality 10-10-10 granular for banding and side-dressing the plants and then other liquid supplements as needed when watering.

I grow mostly organic in the gardens but it doesn't work well in containers with soil-less potting mix.

Dave
containerted
11 years ago
Dave (digdirt) and I use very similar methods of reusing mix. I put all my mix from all the pots into a very large tarp and add some dolomite lime and some 10-10-10 slow release fertilizer. After mixing well, I roll it all up and let it spend the winter working on decomposition. This will allow the calcium in the lime to get closer to useable compounds over time. Also, the slow release will have rejuvenated some of the nutrients lost to watering washout the previous season.

Then, in the spring, I add some new mix to the old as I fill my pots, buckets, and tubs(roughly 25% new mix). I also add some composted manure (usually Black Kow). With another handful of dolomite lime, some Tomato-Tone (from Espoma - about a cup per container), and another small handful of 10-10-10, I fill the tubs and set in the tomato and pepper plants. I add some Miracle Grow for Tomatoes fertilizer to the watering every two or three weeks during the growing season.

When all the containers are properly filled and plants are growing, I use any leftover mix from the last year in flower beds or hanging planters or whatever. So, nothing wasted.

Hope this helps.
garystpaul
Original Author
11 years ago
Thanks, Ted. I follow your posts elsewhere and thus value your advice on container growing.

Question: When you say 10-10-10 slow release fertilizer are you, like Dave, referring to products like Osmocote (timed-release, usually temperature- and moisture-activated), or to the common granular 10-10-10? The reason I ask is that I've never seen Osmocote in a 10-10-10 version (of course there may be other brands).

Thanks,
Gary
capoman
11 years ago
I would not reuse peat based soil, as it is already water retentive and breaks down quickly. Bark based soil such as 5-1-1 from the container forum lasts much longer and can be reused. Best to sterilize the soil though before reusing.
containerted
11 years ago
Gary, because I use some Tomato Tone for the micros, I use the cheapest 10-10-10 slow release I can find. That will take care of the basic NPK's and I can use the "good stuff" for the rest of the formula to get a fairly well balanced growing medium.

Most folks get too detailed in putting together a growing medium. Tomato plants are far more accomodating to less than perfect environments than we give them credit for. I treat them like kids. Give them the best you've got and let them adapt a bit to their environment. My formula is not perfect, but it seems to do well year after year.

Take care and don't be afraid to push the envelope from time to time. It'll teach you just how wide the window for success can be.

Ted
dickiefickle
11 years ago
I consider reusing the potting mix as practical,prudent,and
frugal.
bau the man (uk, bristol,zone 7a)
7 years ago
Do you still use this method in 2016? Digdirt? Dave?.
Seysonn_ 8a-NC/HZ-7
7 years ago
I reuse mine but freshen up a bit with new mix.

Soil is just a medium. As long as it has the right balance of moisture retention and drainage it can be used. Probably a used mix has advantage by keeping some of the nutrients and essential elements fro the previous season.

Sey

PS: clean it from the roots, ... possibly let it get dray and store in a closed container over the winter, where it can possibly freeze.
fungus
7 years ago
Now it's the 6th season I'm using the same mix. It was basically mostly peat with just a bit of perlite. I do add a bit more each year (since it compacts and also gets lost a due to wind, birds, etc) and try to fluff it in the spring (directly in the pot since I don't want to get my balcony dirty). Also remove the previous roots (also in the spring, when they are more decomposed).

Still getting good production, can't say there is a big difference compared to first year (there is a bit).

As to if you should let it rot/freeze in the winter... hard to say, I'd think maybe put the pots in a sheltered place where it will slowly get bone dry. Letting it rot/freeze will highly accelerate compaction. I use organic fertilizer btw (manure based)., adding some in the spring and incorporating on the surface every 2 weeks or so a bit more.

Container Toms: Reusing this year's mix?

Comments (14)

missingtheobvious

digdirt2

Related Discussions

garystpaul
Original Author

garystpaul
Original Author

mewhee

digdirt2

containerted

garystpaul
Original Author

capoman

containerted

dickiefickle

bau the man (uk, bristol,zone 7a)

Seysonn_ 8a-NC/HZ-7

fungus

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Container Toms: Reusing this year's mix?

Comments (14)

Related Discussions

garystpaulOriginal Author

garystpaulOriginal Author

garystpaulOriginal Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

garystpaul
Original Author

garystpaul
Original Author

garystpaul
Original Author