This article was written by Lucille Saunders, Coles County Master Gardener.

Make collecting containers a hobby. If you are going to plant in a container you have to have a container. The container doesn't have to be a clay or plastic pot, it can be anything that will hold soil – or into which you can place something that will hold soil. I've seen old bathtubs filled with flowers (hey, that's a container), birdbaths, small wagons, chairs with a hole cut out to hold a container – anyway you get the idea. Fun thing to keep in mind when you go to garage sales.

Now you need to plan what will go into the container. It really helps to have a plan in hand when you purchase the plants. It will save money and trips to the nursery. I could list many plants but best you go to the nursery, look at what is available with some plan in hand. Consider the number of containers, the color of the container and the size of the container in relation to the plants for that container. Know the number of containers to fill, the number of each type of plant (thriller, filler and spiller) you will require for each container and the color scheme you want to carry out. Group the plants you are thinking of buying for each container together in a shopping basket to get an idea of the contrast in colors and shapes. Consider whether the plants for each container prefer the same type of exposure (sun, part sun or shade).

Preparation: The container needs to be clean on the inside especially if used previously as a planter. That was one of the suggestions in my last column – cleaning containers by washing out with a mild bleach solution, rinsing well and drying before filling.

Large containers will take a lot of soil but to eliminate the need for enough soil to fill the pot, add drainage material to the bottom of the pot (be sure it has a drain hole – or drill one) such as inverted nursery pots from purchased plants – the larger the better for the large pots. Packing foam peanuts are suggested but frankly I find them very messy when you have to dump out the soil at the end of the season with plans to use it to fill up low areas. I like to use crushed soda cans (leave uncrushed if it is a HUGE planter). They work great for drainage and for filling up the bottom of the pot.

Next comes a good potting soil, perhaps even the kind with time-release fertilizer if you prefer not to fertilize in the weeks to come. Very large planters that have been used the previous year need not be totally emptied if you know disease was not present the year before. Remove the top one-third of the dirt and replace with new potting soil. I usually "water" the old soil with a liquid fertilizer or mix in some time-release fertilizer before adding the new soil.

Now it is time to plant. This is the part many people find intimidating. Follow the "rule of container planting" suggested by many horticulturists of Thrillers, Fillers and Spillers. This three-ingredient recipe takes the mystery out of planting a very attractive container. The "thriller" is the centerpiece plant with star quality, something big, bold and beautiful – such as Purple Fountain Grass (Pennisetum sefaceum 'Rubrum'). If the planter is to be viewed from all sides, this plant should be placed in the center. If it will be viewed only from the front, place this plant in the rear of the container. A nice filler plant with the Purple Fountain Grass would be a pink coleus (Solenosteman scutellarioides 'Bellingrath Pink'). The "filler" is usually foliage or flowering plants that will complement but not overwhelm the main player (the thriller). Then add a splash that is called the "spiller" – a plant that tumbles out of the pot such as sweet potato vine (lpomoea batatas 'Margarita'). As long as you select a thriller, a filler (fillers can be a variety of plants to add mass to the overall composition. The filler is usually a mounded type plant so hides the bare bones of the thriller), and a spiller whose function is to spill over the side of the pot and should either echo or contrast the other plants by virtue of color, texture or shape, in various proportions. With consideration to the balance of colors and textures – and the color of the pot, you can create a container that will add a lot of interest to your overall garden plan.

Remember you can always add or subtract plants from your container. The best part of containers is they are mobile. We put them where we want but if the plant doesn't like the location, the container can be moved.

And another suggestion is Potscaping. Containers planted as suggested can be used but filling each container with only one category of plant and arranging a whole series of pots to make a giant container planting. You can use inverted pots or boxes to raise some of the containers that will be hidden by the shorter containers. Have fun – this is a moveable garden and easily changeable garden.

Container planting does not have to be limited to annuals. One side of my yard is concrete so wasn't possible to plant in the ground. Container gardening was the only solution. Now several of the containers couldn't be moved with a Mack truck because they are large landscape boxes that I didn't want to have to replant every year so they are planted with perennials and shrubs, including ivy, day lilies, Templehof Hinoki Cypress evergreen shrubs, Viburnum 'Mariesii' (snowball bush), even a small holly bush. If you like roses but don't have room or the soil for them in your garden, put them in a container. I have Stella d-Ora daylilies in several containers but any daylily would do fine – won't spread as much but that is okay. Even Hostas will do well in containers and can be left outside in the container over winter if it has enough soil. What a delight to see it reappear in the spring. Be creative.