If you've got a lot of containers to plant, or can't find a soil mix that you really like, then make your own. (You will probably find that you'll save some money by doing this, also.) I amend packaged potting soil 99% of the time. What I add depends on the type of plant I'm planting.
I've provided 6 plant-specific recipes for making very good quality potting soils for your container plantings on the following page: Homemade Potting Soil Recipes for Container Gardening.
Since We're on the Subject of Good Quality Soil,
Let's Talk About Nutrient Requirements
Plants in containers will use up nutrients rather quickly. Because water drains rapidly from good quality potting soil, the fertilizer is slowly washed out as you water.
Remember to fertilize often. I use a granular water soluble mixture and get great results. Other gardeners prefer liquid fertilizers, such as fish emulsion. Whatever your preferred fertilizer, just follow the feeding instructions on the package.
How much fertilizer? Some experts recommend diluting any type of fertilizer to ½-strength for containerized plantings. Personally, I have always mixed my fertilizer full strength and have always had healthy plants. I have not had a problem with excessive salt build-up, either. You make up your own mind on
this one! :-)
How often to fertilize? Most container plantings have to be watered at least once a day in hot weather. And because of this, fertilizer requirements normally increase. I have found I really ought to fertilize my most demanding/heavy feeders about every 7-10 days, like my Brugmansias. I'll admit that I sometimes go longer than that (shame on me!). The Brug's let me know if I've been lax … I can tell by the color of their leaves.
But you know what, even though I've read many articles stating that container plants need almost weekly feedings, I've not always found that to be the case. I've got some plants that have lived in containers for years, and I fertilize them once a month during the growing season. They are quite healthy and robust.
You know ... I'm no specialist when it comes to fertlizer requirements, but I'll tell you, I do have years and years of experience with growing all kinds of plants in containers. I really think you just need to pay attention to what your plants look like and if they are or aren't flourishing.
Research and learn about the growing habits
and needs of each plant you cultivate.
Watch how they grow, the color of their leaves, etc.
Use your common sense when it comes to your
fertilizing schedule for your containerized plants.
