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What to do with soil in containers after harvest?

Posted by gardengirl3 8 (My Page) on
Fri, Sep 27, 13 at 3:37

I live in the Portland, Oregon area. I grew potatoes in three potato grow bags this year and just harvested them this past weekend. I don't know what to do with the soil though, can you use it again next year to grow potatoes in or what do you do with it? Would the soil get compacted or hard or loss its nutrients?

Thank you for any advice!

Follow-Up Postings:

RE: What to do with soil in containers after harvest?

Yes you can use it again. You may need to add some fresh soil to it I would add compost, either home made or store bought.

RE: What to do with soil in containers after harvest?

Thank you, I think I will do this because it seems like a waste to throw away the soil each year, but I heard something about rotating every 3 years where you grow potatoes. I guess that is to prevent disease. I also found slug eggs in one of the bags, I think they all hatched now.

Do you think I should take the soil out of the bags and store it elsewhere or just leave the soil in the bags all winter? Right now they are outside with a trash bag laying on them to protect them from the rain, with some leaves on top of the dirt to add nutrients to the soil.

RE: What to do with soil in containers after harvest?


What kind of soil did you use for your potatoes? Was it a peat-based bagged soil like Miracle Gro or did you mix the soil yourself?



RE: What to do with soil in containers after harvest?

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sun, Nov 17, 13 at 13:19

This is a copy/paste job from something I left on another thread a while ago:
In my estimation, the only convincing 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 (any one'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 medium 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.


RE: What to do with soil in containers after harvest?

I would store the potting soil away from rain.

Soil, potting mix ,of any kind, are media, to which we add nutrients. Soil less mixes are basically without any nutrients. After they blend them, they add nutrients to them. So the medium is medium. why trow away your money?. You may choose to freshen it up a bit, after you discard the old roots.

RE: What to do with soil in containers after harvest?

Thank you very much everyone for you help and advice!

In the potato bags, I used Dr. Earth's Home Grown®
Vegetable Garden Mix. You can find it here at:

I also used one of his organic fertilizers called Organic 5® Tomato, Vegetable & Herb Fertilizer.

I bought these two products at my local nursery.

I read that, as some have already mentioned, that when the soil is not loose anymore and/or soggy (when watered) to dump it out and get new soil. I have this problem with some hanging baskets and one container that I put flowers in, but it was regular potting soil I used for those, not the expensive stuff haha. To keep the soil from compacting from the frost, I was thinking of bringing the soil I want to use next year into a bag into the garage.

RE: What to do with soil in containers after harvest?

I have to make a point clear: NOT ALL CONTAINER PLANTING is the same. Just case in point : Planting potato in a container is not the same as planting a houseplant that will be there for years. They plant tomatoes, potatoes in the open fields with average soil , year after year and they do fine. What they do is they till the field to aerate and loosen it , add nutrients to it and replant. So, I think with a fairly better than average potting mix you can reuses it for years. You can further amend it, for example, by adding some more pine bark.
PS: Potato plant's life cycle is just about 3 months. And it prefers fluffy soil.

This post was edited by seysonn on Mon, Nov 18, 13 at 20:43

RE: What to do with soil in containers after harvest?

i start fresh every yr with new potting mix.. the old..goes into the vegy/flower gardens.. i know the addition of pumice only helps in drainage.."its a good thing" LOL couldnt help myself..:) lol

RE: What to do with soil in containers after harvest?

Well this mix contains everything but the kitchen sink, but it is advertised as a planting mix not a potting mix. Used as a raised bed component I am sure it would be useful for several years, but for more than a year or two at the most in a container, it would be found wanting. I am sure it sells at a premium price, but for containers, I would use something less expensive, that I would not mind discarding every season. Al

RE: What to do with soil in containers after harvest?

HANGING BASKET with so many flowers in a small pot is not the same as ONE potato plant in a big container.

Flowers in hanging baskets root bound easily. But potato plant does NOT grow a whole lot of roots. So, yes I would replace hanging basket mix..

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