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Gardening in north Florida is a contest with the sand. An old friend who farmed here for years says "All that sand is going to do is hold the plant upright...you'll have to do the rest." Any kind of fertilizer, organic or otherwise (other than time release) is very temporary. It's going to wash away in the rain.

The other problem is the heat, combined with the sand will decompose any kind of organic material right now. Dump trucks full of manure spread on a garden and dug in will disappear in one summer. Keeping enough water to the plants is another problem. The sand just drains it away.

All of which eventually led me to container gardening.

The first issue was...


POTTING SOIL

First I used straight peat moss for soil in the containers. - Too expensive and too far to go to get it. There used to be a peat mine here but the guy died and it closed. It was inexpensive but far away.

- The peat (and the roots) get waterlogged eventually and the plant fails if you use straight peat moss without additional drainage tricks. More on that in a minute.

Then it was bagged potting mixes - Too expensive again and I had to drive a good distance to get them. - They worked better

Most potting soils are 50 to 60% fine shredded bark, the rest is usually either compost, topsoil or peat with a bit of perlite, sand or something like that

- Everyone has their own recipe...to the point of confusion.

- It's easy to mix your own potting soil.

Then I found this...the "additional drainage tricks" I mentioned before are in here:

POTTING SOIL - EXCESS WATER IN CONTAINERS DOING DAMAGE TO PLANTS

That was the first, last and the best complete explanation of how potting soils work...or should work.

So I tried his basic mix of:

-5 parts fine pine bark
-1 part peat...I substituted compost for the peat
- 1-2 parts perlite...I substituted NAPA floor dry (diatomaceous earth) for the perlite

He warns somewhere in that article that in hot climates that may not hold enough water. It didn't. I followed his advice and upped the peat (compost) until I got to 3-4 parts of peat and that made the plants much happier.

Fortunately, I'm able to mix my own potting soil because I have all the things like pine bark and compost available at a landscape supply about 5 miles from here. It's very easy to mix your own. You can do it as simply as just turning all the ingredients over with a shovel. It doesn't take nearly as much mixing as you might suspect.

I started all the plants with the Foliage Pro fertilizer he suggests in the article but once the plants got going I switched to a granular one made locally that dissolves almost as slowly as the time relese fertilizers. Most of what I grow is vegetables and they like a whole lot of nutrients so the Foliage Pro would have been way too expensive to use long term.

Why not organic fertilizer? Because it doesn't have enough time for the various forms of microscopic life in the soil to break it down to where the plants can use it. I had zero success with organics.

Here's more on FERTILIZING CONTAINERS

The next problem?

What to use for... CONTAINERS and WATERING

I started out buying 10 Earthboxes: www.earthbox.com I followed the instructions exactly and got pretty good plants and veggie yield. Never anything quite like what they show in the pics on the site but good enough. The heat, humidity and bug population here do make it a struggle for the plants. The fungus and assasin bugs here are going to take them all out by sometime in July anyway. After learning about all the problems resulting from too much water in the containers, which is the opposite of what seemed intuitive to me, I'm thinking all the water being held in the bottom of the earthbox type planters is over saturating the potting soil.

So far, just putting the bottom drilled container right on the dirt (so the dirt wicks off the extra water) and the improved homemade potting mix are getting dramatically improved results over the earthboxes or other containers with a water reservoir in the bottom. Too much water can't be good for fungus issues and fungus sensitive things like cukes are doing much better in the non-water reservoir planters. Cleaning out the earthbox or water reservoir containers at the end of the season reminds me of my old septic tank trucking job. The smell says anerobic bacteria at work and that's not a good thing.

I tried five gallon pails, drilling the bottoms and filling them with the homemade potting mix...which work OK for some things if they're small enough. Stuff like lettuce, greens, carrots and other small veggies. Determinate or dwarf tomatoes will actually work this way too. They won't be as big or productive as they would in a larger container but they work and some folks just don't have the room or resources to use big containers.

Most of the advice you see out there suggests using plastic to mulch the top of the buckets. I use the pine bark I got for the potting mix instead of plastic and it works fine. One less thing to have to dispose of too.

What worked the best overall was always bigger containers. I don't know if it's cutting down the heat on the pot from the sun, the more room for the roots or what...but this was the biggest improvement yet.

The best bigger containers were...

- 10 or 20 gallon grow bags. The ones that are white on the outside and black on the inside. Find then inexpensively on Ebay, sometimes at hydroponic or grow light shops if you have one locally. The bigger bags are often not stocked by local stores.

- Plastic 55 gallon pickle/pepper drums cut in half and drilled for drainage. These seem to make the plants the happiest. These drums are usually red or black with a large screw top and are how most of our pickles and peppers get here to the US. They're easiest to find near port cities.

For staking and trellising I drive a short piece of 1/2" rebar into the ground and slide a 10' piece of the smallest size galvanized steel electrical conduit over the rebar. The rebar is more expensive than the conduit these days. Usually about $1 and change per stick of conduit. I tie twine between them for trellises. Update: The conduit works fine by itself.

I automated the watering inexpensively with a light timer, an electrical irrigation valve and a transformer to cut the voltage to what the valve wanted. The valves are usually 12 or 24 volts so you don't fry yourself if you make contact with the electricity.

I was using drip irrigation with this, with the caveat that the usual drippers will clog up from the minerals so I use the adjustable drippers. Eventually I went to overhead misters and the plants were much happier.

Even with this setup it wastes a good bit of water. I don't like wasting water because we're running out of it here. We're sitting on the largest natural spring system in the world here and things are going very wrong due to drought conditions and too much water being pulled for bottling plants, power plants, development etc. etc.

Plants will need watering 1-2 times daily once they get going so automating irrigation is pretty much a "must do". One day I'll spend the money for a more expensive timer that can go on/off in something less than 15 minute intervals. That would help a lot with water waste.

After reading the gardenweb article mentioned above I now know the plants need a lot less water than I thought. I've had a lot of success using misters on ornamental stuff like shrubs so I'm trying it on some veggies. So far so good despite warnings that some of these veggies don't want water on their leaves. One of the other top tips from that gardenweb article is using something like a shish kebob skewer to check for water needs in the plants. Stick it in the soil then pull it out and see if you can feel moisture on the stick. If yes, then there's still enough water. You still have to be sure that some water drains through to keep the salts washed out of the soil.

Summing it up...

Get the biggest containers possible for your situation.

Get your potting soil matched to what you need in water holding capacity, as in more water in hotter climates.

Get your watering to where it's the right amount but not wasting water. Make sure the excess can wick out of the container by putting the container directly on the ground or building a wick for the container as described in the potting soils article up above.

Use regular fertilizers, not "organics", and not so much fertilizer that you're adding nutrients to the ground water.
 

Update:

Turns out the best container soil mix so far is 1 part compost to 3 parts fine bark chips.

I put some tomatoes out of direct sun in partial shade and put misters on them for water. They were in 10 gallon grow bags on the ground. They were misted 3 times a day. Those plants did WAY better than the others.

A nice gift from mother nature this year...balance of nature and all that. I have lots of lizards this year now that there's better habitat for them. They ate the tomato hornworms, all the flies and I haven't seen any assasin bugs yet.