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
All of which eventually led me to container gardening.
The first issue was...
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
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
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
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
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
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.
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.