How to Plant Flowers in a Large Container That's Easy on Your Back and Your Wallet

Garden accents of flowers in oversized pots are wonderful. Because of their size and weight, however, those large containers of plants can be difficult to move and expensive to fill with potting soil. Now you can use my tips to make large plant containers more portable, more manageable and more economical. Let there be huge pots of impatiens, begonias and coleus under every tree! Petunias and Dusty Miller on every deck! And don't forget front porches, steps and walks. Here's how:

Large pots make large statements

The simple answer to why gardeners like to accent their landscape, as well as the usual decks, porches and walkways, with large containers of flowers is this: large pots make large statements. A garden has many uses, and one very important use is giving us beautiful and peaceful things to look at---and not only while we're in the garden.

For every window I can regularly see out of, I like to try to make a visual focal point of color, whimsy or both in the garden. The point is that the your garden, like a story that unfolds, can be an experience and a canvas that surprises and delights you. And using large containers of accent flowers helps to do just that.

The problem with large containers

Large containers, however, are not---so to speak---all a bed of roses. (Though check out these "Nearly Wild" Pink Roses grown in medium shallow pots; here the pots are used to vary the height of the plantings and bring additional interest to an area that, I hope, one day will be covered with creeping juniper, highlighted with Stella D'Oro daylilies.)

There are two problems with planting large containers of flowers. First, if you take a large container and pot it as usual, you will end up pouring a ton of potting soil (IOW, your hard-earned cash) right down to the drainage hole. Secondly, if you fill a large container with potting soil, once the soil gets wet (if not before), you are likely to find that pot is a real bear to move. It will be very heavy. That makes the container awkward to lift and difficult even to roll or drag. And the weight makes the soil compact so that it's unfriendly to your plant's roots anyway. There is another way!

B.A.'s secrets to lighter, cheaper container planting

Many years ago, after wrestling with a extremely heavy large pot of flowers like I was roping a cow at some kind of rodeo, I sat down and thought about the process. There had to be a way to go big without becoming a cowpuncher.

I realized that most annuals, and even many perennials and small shrubs, needed only about 12 inches of soil for their roots. If I put a bunch of impatiens in a 30-inch high pot, and planted it in the traditional way, I had paid for ---and struggled to pick up and move---about 22 inches worth of root room that those plants did not need.

So here's what I hit upon: now I plant a large container so that it has the amount of soil needed to hold the roots of my plants while the rest of the container is essentially hollow.

How to "hollow out" a large container for planting

The best way to explain this is to give you an example of a container I just potted. (You can follow along with the slideshow open in another window, if you'd like: click here.) I wanted a large pot of impatiens that I could look at out one of my bedroom windows. The area is mostly shady. With taller trees growing there, the scale is large. So, out of my container pile, I grabbed a lightweight plastic pot that was large---24 inches tall and 20 inches in diameter (at the top).

Impatiens do well in 10-12 inches of soil, so I also choose a smaller pot that was about 10 inches high. This pot was one of the throw-away black pots (that I rarely seem to throw away) that plants are sold in. The smaller pot , turned upside down, needs to be able to fit inside the larger pot. Again, choose a pot that leaves room for the amount of soil your particular plants will need.

To create the hollow area inside the large pot, first I covered the smaller pot with a plastic shopping bag. (This is to keep soil from falling through the holes in the bottom of the smaller pot.) I then turned the smaller pot upside down and placed it in the bottom of the large container, as shown here. [Slide 2]

This pot inside the pot creates a large airspace that significantly decreases the weight of the container once planted with flowers or other plants. This airspace also significantly decreases the amount of potting soil needed to fill the large container.

More lightweight filling and drainage, too

At this point, you can pot the container as usual, adding some drainage material at the bottom (around the sides of the smaller, upside-down pot) and then potting soil or mix.

Since I knew my impatiens were going to need only the first 10-12 inches of soil, I continued filling the pot with lighter weight material that is also cheaper than potting soil. Cheaper as in free!

Free stuff to fill the bottom space in your large container may be just an eyeball away. One day I looked around and saw the Sweet Gum tree in my neighbor's wood had dropped a bunch of gumballs on my yard. (See the gumballs at Slide 3.) Then I stepped on a pine cone that had become soft and springy after laying on the ground for a while. It reminded me of the expensive coconut husk mats you can buy at the garden store to line baskets.

And that's how I came to use pinecones and gumballs to fill space and create a nice drainage layer in my large container plantings, as shown in Slide 4. Pinecones and Sweet Gum tree seedpods don't decompose all that fast and, while I can imagine it might bother some vegetables or flowers that are picky about soil Ph, I've never had anything but a happy customer in one of my special "gumball machine" planters.

Plant, water, enjoy

Once you've hollowed out the large container with a smaller container and filled the side space with additional filler and drainage material, such as pinecones and gumballs, press it all down gently. (Please wear heavy gloves if using pinecones or gumballs--ouch!). Add potting soil or mix as usual, as shown in Slide 5. Then plant, water and enjoy! You'll find this large container---with its secret hollow spot---much easier on the back, as well as on the wallet. And your flowers will be just as happy, if not happier, in a container with good drainage and less compacted soil. The finished pot will look a little forlorn at first [Slide 6], but it will fill out beautifully and soon. Now if I could just convince the rabbits to leave my blooms alone . . .

*** Yet another reason to get out in the garden: The Surprising Health Benefits of Picknicking.