Container Potting Soil Requirements

To Grow Healthy Container Plants, You’ve Got To Have Good Soil

What Type Of Potting Soil Is Best For Healthy, Long-Lasting Container Gardening?

The first part of the answer is: probably not the soil from your garden. The soil from your garden most likely is not acceptable to use in your container plantings. Why? Most gardens have soil that contains a high percentage of clay.

Clay is not helpful to your plants happiness. What is clay like when it’s wet? Right … it can be squished into a ball and retain the shape. What is clay like when it’s all dried out? Right again … it turns into a rock hard lump.

Clay will not support healthy growth in plants. The soil on my property is lousy – too much clay content. It supports grass growth and that’s about it. I had to drastically amend it before I could even set a plant in the ground. I removed load after wheelbarrow load of clay clods.

Think about a plant’s roots in soil that has too much clay. The little roots struggle to spread through the dirt. And, if you’re in a very rainy area, the roots stay soggy too much of the time. If you’re in a dry area, the dirt bakes as hard as a rock.

You Want A Nice Friable Potting Mix

The Soil In Your Container Need To Allow The Plants Roots To Breath

The Mix Should Be Porous Enough To Allow Air And Water To Reach The Roots

It needs to retain water well, but not stay soggy. It should drain fairly quickly but hold in enough moisture to keep the roots evenly moist. Most of the potting soil mixes available are very suitable for container gardening.

Soilless mixes: There are two schools of thought on using this type of potting soil. Some say “it’s just fine to use – we prefer it.” The other group of container gardeners wouldn’t touch this type of potting soil with a ten-foot pole.

Now for my opinion: I’ve used all kinds of potting soils over the years for all sorts of plants. Soilless potting soil is very lightweight, is basically sterile and contains little nutrients. Even if the package states that a slow-release fertilizer has been added, I don’t use it as my first choice when planting in containers. Why?

Well, there is the issue of this type of mix being very lightweight. It doesn’t help weigh down your container – which helps stabilize it should a big gust of wind come along. Also, with taller/larger growing plants, their root systems are not “held in” as well by this light mixture. Your plants may fall over once they grow large enough.

You’ve really got to keep an eye on the moisture level if you use a soilless mix. This stuff dries out fast! If you’ve got it in a terra cotta planter, well the terra cotta naturally acts like a wick, pulling moisture out of the soil. Put these two together and good luck in really warm weather, let alone hot hot weather! You’ll probably be watering more than once a day.

All this being said, you can have decent growing success with a soilless mixture. But again, I advocate using a medium that contains soil.

Making Customized Potting Soil

Many Successful Container Gardeners Make Their Own Special Soil Mixes

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 fertilizer 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.

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