This Article Offers Potting Soil Recipes
Specifically Geared To Six Different Plant Types &
Soil Sterilization How-Tos

A large part of the ongoing healthy growth for all container plants lies in the quality of the potting soil used. For instance, some plant types need a more porous soil, others may need a more acidic soil. Click here to read about the basics of Potting Soil Requirements for Successful Container Gardening.

Most of us use an all-purpose blend in our containers. I normally add some "extras" (like coarse sand or compost) to packaged potting soil. Just depends on what type of plant I'm dealing with.

If you've got a lot of containers to plant, or want a better quality potting soil than you're able to purchase, then make your own potting soil. These recipes are specifically geared to the growing requirements of six different plant types. Besides saving you some money, the main benefit from making your own mix is that you can offer your plants soil that they prefer to grow in. This helps increase your success – and your plants happiness!

**Note: About packaged potting soils: For these recipes, it is preferable that the potting soil contains perlite or vermiculite. If it contains a wetting agent, that is an added benefit.

Basic Potting Soil Recipe #1

2 parts packaged potting soil

1 part coarse sand

1 part peat moss or leaf mold

Optional: slow release 14-14-14 fertilizer or bone meal
      as per package directions

 

Basic Potting Soil Recipe #2

1-part packaged potting soil

1-part peat moss

1 part coarse sand

Optional: slow release 14-14-14 fertilizer or bone meal
     as per package directions

 

Acid-Loving Plants Recipe (Azaleas, Camellias, etc.)

2 parts packaged potting soil

2 parts coarse sand

2 parts peat moss

1 part leaf mold

1/3 part well composted manure

 

Bulbs Recipe (Tulips, Daffodils, etc.)

2 parts packaged potting soil

1 part coarse sand

1 part leaf mold or peat moss

Bone meal as per package directions

 

Cacti and Succulents Recipe

2 parts packaged potting soil

2 parts sand

1/2 part leafmold or peatmoss

Bone meal as per package directions

Limestone as per package directions

 

Alpine Plants Recipe

2 parts coarse sand

1 part peat moss

1 part pumice

 

Orchids and Bromeliads Recipe

6 parts **Osmunda fiber

1 part of 1/2 -inch charcoal

Place some drainage material in the bottom of the container: styrofoam packing peanuts, broken up clay pot pieces or small gravel rocks work well.

**If Osmunda fiber is not available, use combinations of other media such as chopped tree fern fiber, bark materials, porous stone (volcanic stone), peat moss or charcoal. As an example, a general guideline to follow would be: equal parts peat moss, sand and granulated charcoal.

Recipe Substitutions:

NOTE: Perlite can be substituted for coarse sand. (Perlite is a sterile, very lightweight, white aggregate made from volcanic minerals.) Perlite permits superior aeration of the potting soil mixture. However, use sand if you need your container to weight more - thusly not as susceptible to blow over in the strong wind.

If You Have Good, Friable Garden Soil, Then You Can Substitute It For Packaged Potting Soil In Each Recipe

However, it is always recommended that you sterilize it before adding it to any potting soil recipe. Take this extra step. Kill off any weed seeds, bacteria, microbes or nematodes that could be harmful to your containerized plants. (Sand can be sterilized by these methods, also.)

For small batches:

• Sift the garden soil through a 1/4 inch sieve
• Preheat oven to 180 degrees F (82 C)
• Place soil on a large cookie sheet and cover with
  aluminum foil
• Place on oven's center rack; bake at 200º F for 30 minutes. **Stir the soil a few times to help heat distibution.

For large batches:
If you're making a very large amount of homemade potting soil, then the easiest method to sterilize your garden is by solarization. The sun's heat will do a fine job of sterilizing the dirt. The best time to do this is during the hottest months (June, July, August).

• Choose a spot that receives full sun and where you'll
  be able to leave the pile of dirt for 1-2 months
• Water down the soil thoroughly
• Cover the soil pile with plastic sheeting (clear works best); secure all sides well
• Allow pile to "cook" for 1 month *minimum* (6 weeks is better)

After 4-6 weeks / Optional steps:

• Remove plastic; turn over/mix the soil thoroughly
• Water down; replace and secure plastic
• Allow to "bake" one month

You now have sterilized soil, very suitable for any potting soil recipe. Be aware you have killed off all beneficial microbes, etc. with this process, too. Some gardeners add organic compost to this sterilized soil to reintroduce the good microbes and bacteria.