Hey, Brody!

Yes, the plastic will raise the temperature.

It would be best to elevate the containers slightly, by an inch or two, to allow air circulation.

A layer of gravel will not improve drainage - it will actually create a layer of water
perched in the soil immediately above the gravel layer.

I have found that by using bark and grit based mixes, I don't have to worry about the
dark stains from the effluent, such as you might get from peat-based/bagged potting soils.

Josh

I disagree, bark can stain water brown. I deal with it indoors with my orchids. Unless you soak bark and rinse and rinse, you will get brown runoff.

I agree with raising your pots, you can find 'feet' to put under your pots. They sell them in Home Depot or any big-box store.

I grew many containers on my deck for over 30 years without any staining to my deck. I used bagged potting soil and there was never any discoloration. I used various things to fill the bottom of the pots to prevent the soil from going through the holes...clay pieces, rocks, bottles, etc.

Just raise the pots so they are not sitting directly on the deck. Plastic tarps will get hot and hurt the wood underneath.

Jane

I've not had stain problems from containers on our deck, patio, or porch. Make sure your containers have good drainage! 5 gallons is a very good size. For tomatoes, always use the largest size container that you can, even for dwarf varieties. The link below may help!

Here is a link that might be useful: Growing tomatoes in pots: how to choose containers

Thanks for the suggestions.

Gravel - I was thinking I would use this at the bottom, over the holes, to keep the soil from washing out when I water.

Is plastic bad for the deck or just 'black' plastic? I'm trying to keep extra water from falling between the cracks so the dirt under the deck doesn't become saturated and breed skeeters.

In the past, when I had my rubber trees on the deck in the summer, the water from their dishes would leave a ring on the wood.

I'll put the planters up on wooden 'X' blocks to get them some air. I can't do that with the kiddy pools but hopefully they'll be ok.

Can you get large saucers which you can raise? They sell those cheap, clear plastic saucers. Buy the big ones.

Using plastic keeps moisture under the plastic. It heats up (either black or clear) and can keep moisture against the wood. The tarps may prevent the water from the pots touching the wood...but it traps the natural moisture from the ground from evaporating. I would not use plastic tarps.

If the pots are elevated, any water on the deck will dry. You probably got rings because the pots were directly on the wood. The most you would get would be the soil running out. That's why I used various things to block the holes. I break old clay pots and use the pieces to block the holes.

I'm trying to locate photos to show you, I had computer problems and all my photos are mixed up. If I find some, I'll post them.

Jane

I disagree, Jane.

I've never had brown effluent from my containers. I grow in bark and grit-based mixes exclusively.
My Hoyas, Orchid, Christmas Cacti, and a few other species are grown in pure or nearly pure bark.
I screen my bark prior to mixing, but I don't rinse it...other than the standard watering.

Brody,
I'm relieved to hear that the gravel will be used to keep the soil-mix in, rather than for drainage.

Josh

Why not use trays under pots instead of plastic? Seems like covering an entire deck in plastic would be hot and moist, neither can be good for the wood. You could elevate the pots from the trays a bit with a few pebbles. For moisture retention in the soil, I love mixing that compressed coconut "peat" in the soil. One package goes a long way.

I disagree with Jane... and agree with Josh. I don't get any staining, either.

I use a grittier mix that freely drains, I raise the pots so there's no chance of water or moisture sitting under them, and I avoid saucers so the water draining out will roll away and the surface under pots dries quickly.

Using saucers will only allow the water to sit, which will saturate the soil and drown the roots. I avoid saucers outdoors.

If your deck is sloped, you shouldn't really need any plastic. I'd elevate the pots somewhat, which will allow air circulation, and allow your deck to dry in between waterings.

I'd also avoid a layer of gravel inside the pot... Josh is correct... it creates a perched water table right above it, which keeps plant roots too saturated. They end up drowning. Roots need to be able to breathe.

The link below contains excellent information on soils and how water behaves within containers...

Here is a link that might be useful: Container Soils - Water Movement & Retention 12

what is good to use to keep the dirt from escaping my drain holes if I don't use large gravel?

Ok, I've nixed the plastic sheet on the deck idea. I'll go with trays under the containers and raise the trays off the deck of the containers off the trays if I can.

Fiberglas insect screen works very well, and is very inexpensive.

Al

You can't go wrong with the screen. ;-)

I've never had any problem with staining either.

JoJo

I'd think that the clear plastic might actually cause some problems, over time, due to the tremendous heat build-up under the film. Maybe not. The black plastic will absorb the light energy and IT will be hot. Anyway, I'm glad that you've nixed that idea.

Since we don't know what kind of potting mix you're using, it would difficult to promise that you won't have any brown leachate. Some commercial potting mediums are pretty 'peaty' and dusty. Raising your pots is a great idea, and you can spray off your deck occasionally to prevent any fertilizer or potting soil residue from remaining on your deck surface long enough to stain.

How are you going to facilitate the water drainage from your kiddy pool? Same way?

That was my thought, too... plastic could create its own set of issues... like trapped moisture from condensation beneath it, unwanted mold or fungi growing under it, excessive heat build up and whatever issues that might create, etc...

The kiddie pools could present a problem... although, if you raised them up on something like up-ended 2x4's or somehow... and used screening to keep any medium inside the pool... it could work.

I think the staining will depend on a couple of things... what type of medium you use, and how clean you keep the deck under the containers by hosing it off. The peatier the soil, the more it will stain, I think. But if you're vigilant about keeping the deck clean, you should be ok.

Quite honestly, I think a lot is going to depend on what type of medium you use. The more inorganic and free-draining, the better.

My soil will be a mixture of the compost from my bins, my huge wood chip pile that I never got around to spreading (now a pile of dirt), and commercial soil.

I'll give the screen over the drain holes a try. For the pool, I'll be drilling drain holes in it and setting it up on 2x4 supports.

That mix will have a lot of dark water draining through it for sure.
You'll need to rinse off the deck multiple times after watering to keep it clean.
The real issue will be the compaction of the mix due to fine particles and organic
(readily decomposed/decomposing) ingredients.

Josh

You will be fine. Sounds like you have good ideas and if you elevate, you shouldn't get any staining.

Growing isn't rocket science after all.

Good luck,
Jane

It might fit under "Earth Science".

If you have compost in the mix, the water will be dark as Josh says.
I make compost tea from time to time, for my in ground garden, the water can be pretty dark.

I've tried mixes as you suggest you'll be using, and it did become compacted as Josh points out.

Last summer I switched to a more inorganic and free-draining mix and haven't had any troubles since.

JoJo

Yep, the compost will continue to decompose more and more, creating that nice dark run-off. Terrific for outdoor plantings, but maybe not so good for containers.

A successful, long lasting, fast draining potting mix will have few ingredients that break down quickly and more components that tend to be very slow to decompose or erode. That is why you will see the mention of BARK so often...it tends to last for quite a long time when used in a potting medium. Chips made from the inner wood (you said wood chips and not bark chips) will break down pretty rapidly, too.

I predict that your mixture might even clog the window screen material, if that's what you decide to put over the holes. ;-(

I've grown very successfully in small conifer bark fines, (much smaller than the mini-nuggets we are familiar with) with some coarse potting mixture and perlite thrown into the batch. It's pretty clean draining.

Speaking of corn and kiddy pools. :-) I've not ever grown corn in containers of any kind (so I'm not speaking from experience) and I am not familiar with kiddy pools, but would this type of container be deep enough for corn?

I know that several people in the past have grown assorted greens in such pools, but don't recall reading anything about any other crop. Perhaps someone has some thoughts on this.

Excellent mention, Rhizo.

"A successful, long lasting, fast draining potting mix will have few ingredients that
break down quickly and more components that tend to be very slow to decompose or erode.
That is why you will see the mention of BARK so often...it tends to last for quite a long
time when used in a potting medium. Chips made from the inner wood (you said wood chips
and not bark chips) will break down pretty rapidly, too."

As Rhizo says, inner wood chips (sapwood) will break down rapidly.
Not only can the rapid decomposition cause clogging of the soil-mix, but it can potentially
lead to nutrient deficiencies (from nitrogen binding) as well as temperature spikes in a
container.

Josh

I agree. Corn is not a candidate for containers. I wouldn't waste the space trying to grow it unless you had a garden. Even then, you need a lot of rows to get good pollination. I think kiddie pools are too shallow.

Pollinating by hand is time consuming and not always successful. I think corn is wind pollinated and if you don't have enough rows, you will not get corn with full kernels. I grew corn for years. Tried it both ways and even in a vegetable garden, you need many rows.

You live in a short growing zone. If your container media is for one season only, bagged mixes with bark and perlite should work fine. If using compost, make sure you loosen it up with bark or perlite. The compost should be broken down if used, and mixed well with the other ingredients. You want good drainage. I would use clay shards or something like that, to keep the drains open. Compost will clog the screen material.

Compost would stain, but if you raise the pots, you can hose off the deck after watering. Does you deck have a sealer on it?

Jane

Here are some Threads on successfully growing corn in containers - corntainers, as it's called! ;-)

Can corn be grown in containers?

The EarthTainer 'Farm' 6/9 - CornTainers are a' Poppin (pics)

Lastly, here's a link to the Search page with 'corntainers' as the key-word:

Corntainers

I hope it helps!

Josh

Brody - it's very difficult to start with a large measure of fine particles, like peat, peat-based soils, compost, coir, topsoil ..... and amend them so they drain well. I copy/pasted an analogy, something I wrote, that illustrates why it is difficult to START with fine particles and end up with a soil that drains well:

"I think the grower's soil choice when establishing a container 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/peat-based soils/compost/coir, which is why the recipes I suggest as starting points all suggest readers 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."

Al

Hey, Brody!

Don't get discouraged, whatever you do. It's actually quite easy to build a fine potting mix without going to a great deal of effort...and maybe with some of the ingredients that you have on hand now! There are really many ways to get the job done right.

I've heard from so many good people who have lost their enthusiasm for both this forum and for their new gardening adventures and I'd hate to see it happen to you.

Josh, I KNEW that someone had posted some great pictures of container grown corn here. I was once one of the nay-sayers about this (corn in pots) until I saw those images, lol. Thanks for posting them.

Wow...so much good info still coming in. Thanks :)

I am going to add some buzzing friends to the mix. I have purchased, and will be making more, Mason Bee houses. Plan to put them around the deck and see if they can help with pollination a little (hopefully a lot).

I won't be discouraged if things don't work out. I have been planting tomatoes in two gallon clay pots, sitting in the driveway, for three years now and they do fine. If my deck project fails, I'll go back to that.

The deck is treated, and hopefully I'll do it again before I set up the deck garden this spring.

I have a hot tub sunken into the deck in one corner, but I don't use it anymore. I plan to build a box over the cover and set planters on top of that.

I'll do some before and after pictures and post them when I get a chance.

Brody

It'll work out! Have fun with your Mason bees. I used to see them all the time when I was working in the research farm at Va. Tech. I can't remember if they put up nesting houses, or not. They are are great pollinators.

Amazing photos, I remember seeing those. I guess it comes down to how much corn you get for the amount of space and work. I tried it a few times and had trouble with pollination. I believe bees do not pollinate as it is wind pollinated.

I was outside shaking stalks trying to spread pollen. Didn't work. Wound up with nice looking cobs with only a few kernels. I didn't try that again.

In the garden, I seem to remember they recommend a minimum of 4 rows. I would plant half the garden with corn and got a great yield. Whatever, it is always fun to try different things in containers.

Other vegetables are easy. Got great carrots and beets, beans, peppers, tomatoes in regular containers.

I agree with Rhizo, growing should be enjoyable. Whatever mix you use will be fine.

Good luck.

Jane

Wow, I missed your mention of the hot-tub. How cool is that! One huge planter, geeez you can have a vegetable garden going in that. No need to worry about your deck.

Have fun and post some pictures,
Jane

...speaking of growing corn in Containers (josh, thanks for posting those links), here is a photo showing it can easily be accomplished:

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Results:

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..and rather than weeding and daily watering your corn, you can watch everything growing in SWCs from the Hot Tub....

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Raybo

Raybo, did you drill holes in the Rubbermaid containers for drainage?

How many stalks per container?

Hi,

I have a small container garden on my deck that doesn't take up any space. I built shelves on the outside of the railing supported with 45 degree braces, the tops of the containers are flush with the tops of the handrails. In 2010 I had 4 containers on the shelf and 2 larger ones on the ground. This year I intend to add 5 more containers to the shelf. I've tried to add a picture but can't seem to do it.

Lew

Can I make a suggestion for the dirt runoff problem? Here's what I do to stop the dirt from escaping my pots: I empty out teabags and tape the gauze-like stuff they come wrapped in, over the drainage holes in my pots. I'd imagine you could just buy some of this material, but I have a box of tea I don't like :p

This stops all the dirt from leaking out, and I've never gotten stains. I do, however, have a painted wood balcony. I don't know if the difference in porosity might make a huge difference or not.

Hahaha...Raybo, the rubber ducky is new this year, eh? :)

I just found something called "pot toes" while looking for other gardening stuff. Search for that terms and you'll find little feet on which to set pots so that water doesn't set directly under them.