Get out a piece of paper and a pencil or fire up your printer. Following is my Potting Soil recipe that I use for my outdoor containers. Ready? Here it is:
40 lb. bag of Top Soil or Organic Peat. This is the rich, dark stuff.
Sphagnum Peat Moss
Dump the top soil into a wheel barrow large enough to hold the entire contents of the bag and allow room for mixing.
Add in a couple of scoops of vermiculite and a couple of scoops of perlite.
Cover the whole thing with some sphagnum peat moss (an amount about equal to the perlite and vermiculite combined, maybe a little more)
Mix together with a small shovel or large trowel.
For container plants, here are some tips and tricks:
For really large pots, I put some light weight filler in the bottom of the pot, like old small plastic pots or empty plastic paks from bedding plants. Sometimes I use 'packing peanuts' but I put them in a plastic shopping bag first to make them easy to clean out in the fall. I've also heard that some people use old soda pop cans. The plants grown in the pot will not have roots that go all the way to the bottom, so this is a way to conserve on soil and making the pot lighter.
Then fill the pot partially with potting soil and mix in some slow release fertilizer, like Osmocote, following the instructions on the label. Add the plants and fill in with soil, tamping down so as not to leave air pockets. Water thoroughly and enjoy.
Some more hints... don't go too skimpy on the plants. Pack them in to give a nice full appearance. Mix up the plants, use whatever looks good together and has the same basic care requirements. Remember that the plants are entirely stuck in those pots, so don't forget to water them regularly. When it is really hot out, you may need to water in the morning and the evening, especially with smaller pots. And even though you've added some slow release fertilizer when you planted, you should use a liquid fertilizer on occasion to give the plants a boost now and then. With all the watering, the fertilizer will leach out of the soil faster than if you had planted in the ground.
Tuck the plant labels into the side of the pot. If you decide you have a winning combination of plants that you want to repeat the next season, the labels will be right there to remind you what you planted.
People often ask if they have to empty their pots at the end of every season. I generally empty the smaller pots completely, but for large pots, I may just scrape off the top few inches of soil, and add some fresh potting soil on top with more slow release fertilizer. Every few years, I also make sure to empty these pots entirely, also.
No matter where you live, there should be a spot or two for a few containers of plants! You can start planting these now, because if there is a cool night with a threat of frost, you can move them into the garage or a covered porch for protection.
With proper watering and an occasional shot of fertilizer, you'll have an entire season to enjoy your plants.