Kalak
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Reusing soil/compost (containers) next year?

Hello lovely gardening people. Not sure if this question should be in the 'container gardening' section, but it's here because my question is specifically in relation to growing vegetables.

My -- small -- garden is 'containers only', as there is no existing soil -- just concrete and gravel. I spent a small fortune this year (my first time ever gardening) on organic compost to fill a very great number of large pots. I was hoping to use the compost in them next year, but here's the thing: we were very badly attacked by slugs this year and a good deal of the plants were wiped-out.

I'm hoping to get on top of it next year (thanks, in part, to the advice I found here). But will the soil be reusable? Will there be slug eggs in it? How long do those things live? I don't want to fork out all that money again... :?

imafan26
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Re: Reusing soil/compost (containers) next year?

if you had disease or pests in the soil it could be reused if it is sterilized first. It would kill most of the weed seeds and pests in the soil, but also kill the good bacteria. I am lucky I can take my old soil to the garden where I volunteer and sterilize it in the soil sterilizer. I did the cooking of the soil in the oven once, but I will never do that again, it stank.

Some people said they have sterilized the soil by putting the soil in a bucket and pouring boiling water over it. It did not say if the soil had to sit or if it was allowed to drain. They still said, 50/50 old and new soil worked best.

I have a lot of problems with weeds and unbalanced pH and leftover nutrients in pots, so I recycle my used media in the yard. but you don't have that option.

The soil could be spread out in summer and dried in the sun and sifted to get rid of left over decomposing roots, and plant debris. It. will kill some of the things but not virus and it won't fix pH and nutrient imbalances.

When I reuse soil that has not been sterilized, my biggest issue has been the weeds that keep growing back. I also sometimes have problems if I use all old mix in my pots because of the nutrient imbalance especially if I put all the soil back in the same pot. I have gotten around that a bit by only using half old soil and adding half new. I still get weeds but better balance. In old media you have to be careful about fertilizer since plants will take up different amounts of nutrients at different times so you may be heavy on some nutrients and weak on others and you would have to do a soil test to find out how to fix it. I think that is why mixing old and new soil works better at mitigating the problems.

slug eggs can remain dormant up to two years... scary. Even scarier, slugs have a potential lifespan of 25 years. I'd like to know who kept a pet slug for 25 years to do the research.
Happy gardening in Hawaii. Gardens are where people grow.

Kalak
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Re: Reusing soil/compost (containers) next year?

Imafan26 -- thank you so much for your detailed response. You've given me a lot to think about. Might look up the boiling water trick. Slug eggs live in the soil for up to two years? Ye Gods... :eek:

I might do the half new compost thing -- no way I want to keep forking out for that amount of compost every year. Got hardly any food out of it -- lots of (green) tomatoes, though. And enjoyment, admittedly.

Susan W
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Re: Reusing soil/compost (containers) next year?

There are several ways to approach this, as there are people, situations, climate etc. For me, I am trying for a living soil in my pots. I have herbs (sell fresh cut at market), flowers, a few veggies, 100+ pots from 12 -16". My climate probably similar to yours, zone 7 and 50+ inches rain, but do have hotter summers.

As I have mentioned several times, try to find a top soil and bagged poo with sand to be part of the total mix. This keeps your pot draining and loose. There are also earth worms in most every pot. Sometimes your old plant is pulled out in fall, say tomatoes, but you can leave a bunch of root in there as organic to break down. Some plants left in for the winter, such as parsley, then pulled in spring, top few inches of soil refreshed, plant new. I dig down enough to check for worms and look at soil. For perennial herbs and flowers, I try to get around to all of them, loosening the top few inches, cleaning etc, work in a few inches of fresh and get soil lever back up. I figure if worms are active, soil loose, all is well, try to leave the bulk of soil untouched to build the living soil. Some plants you want to rotate. For example put tomatoes in a different pot. Sometimes it helps to put a plastic tag in come fall, with Tomatoes (variety) 2015, Beans, variety 2015 etc.

If some soil cleaned out from top or pot dumped for whatever reason (not disease) it gets put in my enriched dirt pile aka compost. I did dump a large pot the other day that had been neglected for several years. I dumped it in the pile and a couple of worms as big as snakes wiggled out. Yikes!

Slugs? Yuck! Next season try the Sluggo or whatever brand that is granular with iron. It's in the organic -OK to use category, but even then I try to use sparingly. I try not to have pots directly on ground or concrete. They are up on something, no saucers. I use pallets for many of them. Many smaller 12" pots on plastic shelving. Mine is from Home Depot, the shelving with grid, not solid, so it drains.

Hope this helps!
Have fun!
Susan

Kalak
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Re: Reusing soil/compost (containers) next year?

Susan W -- thank you for the great information. I've been feeling slightly discouraged by the whole slug thing (though not defeated). Most of the pots are on the ground or decking, though some are on shelves. Slugs still got them. I'm wondering just how high those things can climb. They also got into my 'greenhouse' -- a plastic creation. Will work hard to stop the same thing happening next year. Happy gardening!

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rainbowgardener
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Re: Reusing soil/compost (containers) next year?

Slugs can climb.

You mentioned compost in your pots. Was it mixed with anything? Compost by itself is usually too heavy and moisture holding for pots; you want something better draining. Keeping your soil too damp probably contributed to the slug issues.

If you want to be careful, I would probably dump the soil in your compost pile and start over with good potting soil, or some mixture of peat, perlite and compost. Definitely start your own compost pile, compost all your garden wastes and kitchen scraps, etc. Then you will have free compost and the best kind.

Best wishes!
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

Kalak
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Re: Reusing soil/compost (containers) next year?

Re -- rainbowgardener. I'm embarrassed to say that such is my overall ignorance, I call everything that plants grow in 'compost'. We've mostly been using bags of Laverstoke Park Compost Mix, which is organic (I hope). Not cheap. I'm going to do things so differently next year...
I started a compost bin a few months ago -- half veg/fruit peel, egg shells, coffee grounds, leaves and clippings -- and the rest is cardboard, paper, etc. That one is now full (only 4 feet high because of space issues). So we just bought another one.
Thank you so much for your advice. I feel it's all one-sided just now, with me asking daft questions all the time, but I don't know enough yet to help anyone.

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Allyn
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Re: Reusing soil/compost (containers) next year?

Kalak wrote:.... I feel it's all one-sided just now, with me asking daft questions all the time, but I don't know enough yet to help anyone.
There's nothing wrong with that. :) Questions you ask benefit other folks, too. For every seemingly "daft" question someone asks, a couple of other folks wanted to ask, but didn't, so they benefit from the answers; and a couple of folks didn't know they needed to ask so the answers turn out to be something they needed to know anyway. When you look at it that way, you are already helping people. :)

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rainbowgardener
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Re: Reusing soil/compost (containers) next year?

Not ignorant - I hadn't paid attention to the fact that you are in England. It's one of those differences between "real" English and American English. :) In the UK, people say compost to mean what Americans call potting soil/ potting mix. (But then you also call the product of a compost pile, compost? Seems confusing.)
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

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