Container Gardening Rules

If you want to have amazing container gardens, there are some container gardening rules that apply universally. There are a number of factors that you need to think about before you begin; size and color of pot, eventual plant size, soil, design, (flowers, color, foliage, shape etc), season extenders, and feeding of your mini-garden.

I’ll walk you through each of the rules in this post.

container gardening rules

A Spring combo in Vancouver, British Columbia.

Basic container gardening rules

1. Size and color of the container:

The size of the container matters a lot. Your plant will only be limited by the size of the container it’s grown in. If you want your plants to reach their full potential, then you need to provide a pot that’s big enough for them to reach maturity.

For example, you need at least a 27″ pot to hold a Canna, a couple of small leaved coleus, a couple  of sweet potato vines, a smaller trailing flowering plant like a calibrachoa or superwave petunias. You might also want to add a tall annual grass to the mix for height and movement.

The color of your container is also important. It’s probably best if the color of your pot isn’t fighting with your plants for attention. But I do find a large, bright blue container irrisistible. The key to it working is that the plants should not clash with it.container gardening rules

2. Drainage:

Unless you’re planting a bog garden, you need to choose a container with good drainage. I recommend covering over the holes of the bottom with landscape fabric, then a layer of stones and then another layer of fabric because you don’t want the soil to mix in with the stones and prevent the water from draining as it should.

Always check the container for drainage holes. If there aren’t any, you need to make some.

3. Correct soil:

Always choose potting soil for the type of plants you’re planting in the container. Never use garden soil. It will hinder the drainage of your pot. For succulents, you need a very free draining, gritty mix. For most other plants, ordinary potting soil will do the trick.

4. Nutrients:

At the time of planting you can add the recommended amount of slow release fertilizer for the size of your pot and just work it into the top few inches of soil. I would also add some compost or well-composted sheep or cow manure to the mix and work it into the soil.

The amount of rain you get in a season determines how much fertilizer you may need to add to supplement the slow release. Rain leaches nutrients out of the soil in containers very quickly.

5. Plant size:

This is one of the container gardening rules I can’t stress enough. Those plants might look small when you put them into that container… but they grow! I had a brilliant idea for a beautiful container garden that I made. It had a lime green juniper in the back, for height, (ha!), and three lily bulbs tucked in around it. Beside it, I planted two pretty purplish red coleus, and a purple-flowered Chrysanthemum. It was a really pretty combination.


container gardening rules

The perfect combination turned mammoth coleus overload!

The pretty little purplish red coleus turned out to be a mammoth coleus! Beautiful, but it smothered my little juniper. and completely shaded out my Chrysanthemum! But, in my defense, I bought the plants and made the container garden in Hong Kong and there was no information to go by to guide my choices. This can happen even where you live. So, unless you really know what you’re buying, buy plants with labels that are clearly marked.

The main point here is to match the vigor of your plants. They should all grow at about the same rate so that no one plant takes over the whole show. The plants should all be seen and compliment one another.

Container Gardening rules

Baby Coleus at the Flower Market in Mong Kok East.

6.Design element:

One of the most important of all container gardening rules is the design. Choose plants for architectural beauty, foliage color, height, movement, foliage shape, flowers. The colors of the foliage and flowers should be complimentary. 

Think about these things:

  • architectural beauty
  • foliage color
  • foliage shape
  • height
  • plant growing habit; spreading vs. filler
  • movement
  • flower color
  • will it provide food or shelter for the birds and bees?

It is entirely possible to have a container garden based on foliage alone. Flowers are ephemeral and don’t last. So you need gorgeous foliage to carry the show while the flowers are having a break. Think about the color and shape of the leaves. And the size.

7.Grow for year-round beauty:

Maybe this one applies more to warmer climates. I’m just thinking of what I have in my garden that thrives in it’s container all year long. I have two Poinsettias, a Camellia, Catharanthus, a weeping fig tree, two junipers, two Buddhist money trees, Dianthus and two scented geraniums that are tough as nails on my rooftop garden. Except for the junipers, the rest have performed very well through the winter and the summer. The junipers haven’t been through a summer in my garden yet. The verdict is out on them. Just recently I have acquired a Hibiscus. It has shown no signs of fatigue in the sun. heat and humidity. So, hopefully, it’s a keeper. Next on the want list is a Bourgainvillea. Both Hibiscus and Bourgainvillea bloom year-round.

A word on Coleus. They don’t like hot sun in hot climates. I don’t know how they do in the shade because I don’t have any. So, my coleus is an annual in my garden because they usually succumb to the heat and drop all their leaves. I need to start planning what to put into those pots soon. (What a hardship! Ha!) Back to the flower market…

8.Keep it simple:

Lastly, follow the K.I.S.S. rule. Keep it simple stupid. Create grand designs with simple color schemes. Designs using monochromatic palettes or two complimentary colors are the most pleasing. Colors that fight with each other are too hard to look at.

Anyone can have a beautiful container garden if they follow these simple container gardening rules.

What gorgeous plant combinations will you come up with this season? 

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