Gardening and Horticulture - filling barrel planter

We have seven half-barrel planters that look just like this http://i207.photobucket.com/albums/bb153/sgull1/200px-Plant_dolly13_659.jpg but without the flowers and casters. We want to plant the type flowers in them about like what is shown, pansies or whatever. I know I should put gravel in the bottom to help with drainage. But with these type of flowers where the roots probably don't need the soil to be very deep, I don't want to put go to the trouble and probably expense of having to buy a whole lot of soil or buy a lot of soil additive etc that might be unnecessary as far as depth. Same with the gravel or rocks that will go into the bottom. How deep should the gravel be from the bottom? And how deep should the soil be from the top of the gravel to allow for enough room for the flowers to grow properly. Any suggestions for reducing the amount of soil and/or gravel necessary, maybe a way to lighten the load? My feeling is why have to use so much gravel and soil for a few lightweight flowers. And I have no choice, the flowers have to be in these half barrels. Any comments/advice appreciated. Non-green thumb here.

I've seen several places that you can use large packing peanuts in the bottom, then cut some window screen to go on top, then gravel and soil.

I guess you could also use 2" styrofoam cut in circles of the correct size.

Remember, it will make the pots a little top heavy, shouldn't be an issue with the barrels though.

EDIT...oh as to the gravel and soil depths..I normally put about 1" of gravel, and 4" of soil. Don't use outside soil from the yard, or garden soil. I believe potting mix is more appropriate for your needs.

BTW I have about 8000 sf of gravel 2-3" deep you can have. Save me $1200 to have it hauled off.

I've known people to use a variety of materials to help fill up a large planter or barrel etc.Material like bricks,large stones,broken flower pots etc.

What you use and how much you use somewhat is dependent on the pot and it's construction.Too much weight in a container in poor condition or made of weaker material can cause problems.

I don't particularly like styrofoam for this as the weight on top will create a long term issue of compressing the styrofoam down more and more.A possible alternative is rubber mulch if you can find it.Also the top heavy issue can be a problem which is why a local greenhouse I know doesn't let it's staff use light material in the bottom of large containers like a barrel.Too many have been knocked over and such.

I've seen several places that you can use large packing peanuts in the bottom, then cut some window screen to go on top, then gravel and soil.
EDIT... as to the gravel and soil depths..I normally put about 1" of gravel, and 4" of soil. Don't use outside soil from the yard, or garden soil. I believe potting mix is more appropriate for your needs. BTW I have about 8000 sf of gravel 2-3" deep you can have. Save me $1200 to have it hauled off.

I do have access to lots and lots and lots of large packing peanuts, so if I went that route it might work out well for me. Questions:
1. I have some of that nylon type material window screen I could put on top, would that be ok you think?
2. Are you pretty sure I would need only about 1 inch of gravel and only 4 inches of soil for the flowers?

Comments:
1. Yeah, gonna use store-bought potting soil not yard or garden soil.
2. No thanks for the offer of the gravel. I should have enough already especially if I need only an inch in each planter.

I've known people to use a variety of materials to help fill up a large planter or barrel etc.Material like bricks,large stones,broken flower pots etc. I don't particularly like styrofoam for this as the weight on top will create a long term issue of compressing the styrofoam down more and more.A possible alternative is rubber mulch if you can find it.Also the top heavy issue can be a problem which is why a local greenhouse I know doesn't let it's staff use light material in the bottom of large containers like a barrel.Too many have been knocked over and such.

Yeah, I could probably put some big rocks or bricks or whatever to take up space in the bottom of the barrel and give it enough weight to keep it from being knocked over. I wonder whether if I was to use styrofoam peanuts (over/above the big rocks/bricks) with window screen covering the peanuts on the top if the weight of the gravel and soil above it would cause the compression problem you mention.

All depends on the type of flowers and how tall they get..if a low spreading type thing it should be plenty. If they grow taller, then yes you may need to go deeper. Even 5-6 inches is no big deal. An inch or so of gravel should be plenty as long as you have the screen. You would need more if you were putting it directly in the bottom.

The nylon window screen is exactly what I use, it doesn't degrade or corrode, you can cut it easily, and if a bit oversize, it folds up against the sides. You could even staple it to the inside of the barrel if you liked.

The barrel is probably plenty heavy enough to be stable and the potting soil won't really be that heavy. I don't think compression over time is much of an issue myself..you'll be emptying and storing at the end of the year right? If it were one of those whole barrel things you sometimes see with flowers at the top, that would be different of course.

JMO from doing it around the house, no expert.

The nylon window screen is exactly what I use, it doesn't degrade or corrode.
The barrel is probably plenty heavy enough to be stable and the potting soil won't really be that heavy. I don't think compression over time is much of an issue.

Okay great. Thanks, it looks like I'll be good to go then. :thumbup:

I've done the same thing, using packing peanuts to half way fill the tub, fiberglass screen or landscape cloth on top and potting soil the rest of the way. I think you might do better to have 10"to 12" of potting soil. It will retain more moisture as the weather gets warmer and your plants won't be as rootbound.

Newt

I've done the same thing, using packing peanuts to half way fill the tub, fiberglass screen or landscape cloth on top and potting soil the rest of the way. I think you might do better to have 10"to 12" of potting soil. It will retain more moisture as the weather gets warmer and your plants won't be as rootbound.

Okay thanks Newt. How about the gravel, is just one inch probably enough? Or, it seems with using the packing peanuts I wouldn't need gravel at all, would I?

I don't bother with the gravel. It takes up space where soil and roots can be and sometimes even holds moisture. You can read this about the 'Myth of Material Drainage in Containers'.
http://www.puyallup.wsu.edu/~Linda%20Chalker-Scott/Horticultural%20Myths_files/Myths/Container%20drainage.pdf

Newt

I don't bother with the gravel. It takes up space where soil and roots can be and sometimes even holds moisture. You can read this about the 'Myth of Material Drainage in Containers'.
http://www.puyallup.wsu.edu/~Linda%20Chalker-Scott/Horticultural%20Myths_files/Myths/Container%20drainage.pdf

Hmm that article definitely blows away all I've ever heard about how it's supposedly so important to put gravel in the bottom of containers. In the "Bottom Line" section of the article, one of the statements is "'drainage material' added to the bottom of containers will only hinder water movement'." Wouldn't that also apply then with the packing peanuts? In my case (with the half-barrel planters) I'd be substituting soil that would otherwise be beneath the soil the flowers are rooted into with the peanuts, which although they'd be there for the reason of lightening the heavy load they would also be acting as drainage material in effect also, would they not? And if they are acting as drainage material then, according to the article, water movement would be hindered, which I guess would be bad.
Heck, it seems like as soon as one thing gets uncomplicated, that just causes another complication.:(

Without reading the article, I'd guess they talk about how soil will fill the spaces between the gravel, and since the rock is pretty impermeable, you now have less area for drainage?

I should probably have qualified my earlier posts. I haven't done a barrel or big planter in a while, but when I did, I used as I described. In smaller pots, I put the gravel, then the screen, then soil (and since I have plenty of gravel now, cheaper too..lol). I'd guess the peanuts would work just fine w/o any gravel, and you could put a few bricks in the bottom if you felt the need.

You are only trying to fill part of the space in a large container. I'd hazard a guess that the screen provides more than enough drainage area, and will prevent the majority of potting soil from draining through and mixing with the peanuts.

OK I went and looked..you notice, no mention is made of any screening or divider between the layers. Won't argue with a Pro (not you Newt, the author of the article, though yer one too, IMO, lol), but a nice well draining potting soil mix should drain, as long as you give it a place to drain to.

One of the other materials I use for keeping the soil from seeping into the peanuts or anything else I use to fill the space, is landscape cloth. It's like felt and lets the water drain through but not the soil.

In my flowerpots where I don't have extra space I don't put anything for added drainage. I find that very little of the potting medium drains out.


Gunguy, thanks for the compliment.

Newt

Okay then I've decided to fill the half-barrel planters about two-thirds the way up from the bottom with styrofoam peanuts, add no gravel, cover the peanuts with landscape cloth, add eight or ten inches of potting soil, and plant the pansies. Thanks for all input and suggestions here.

Sgull, you are so very welcome! Glad we were able to help.

Newt