Jennifer Schultz Nelson
Extension Educator, Horticulture
Hopefully, you've already figured out a gift for mom this Mother's Day. If not, consider creating a container garden for her. While bouquets of flowers are nice, a pot of colorful annuals should last well into the summer, if not longer. Mother's Day, or approximately May 15th is also considered the safe "frost free" date for the area. So annuals will be flying off store shelves this weekend.
Whether you're creating a Mother's Day gift or not, choosing plants for a container can be intimidating. You may think you're not creative enough, or that you don't know enough about plants. But with a few tips and tricks you will be designing container gardens in no time. You need to start with the basics.
First, choose your container. Consider where it will be in your landscape. You may want a pot that coordinates with your house, or looks good in a particular corner of the garden, but it's also fine to just pick a pot that you like for no other reason than it appeals to you. Whatever you choose, make sure there is a hole in the bottom for drainage. This sounds really basic, but it is easily overlooked when shopping.
If you are going to place your pots in a sunny location, remember that unglazed clay pots will dry out relatively fast in the sun. You may wish to choose a glazed ceramic or even plastic pot for a very hot sunny location. Also, it may be a good idea to go with a pot on the larger side, as a larger volume of soil will dry out more slowly than a small volume of soil in a smaller pot.
The down side of larger pots is buying enough soil to fill them. It would cost a small fortune to fill some of the giant urns and pots out there! Most annuals develop a fairly shallow root system, around six to eight inches deep. So it's really a waste to have soil two feet deep in a pot! Instead, place inverted plastic pots, large Styrofoam packing pieces (such as those that computers and other electronics are shipped in) or a plastic bag of Styrofoam peanuts in the bottom of your pot to act as filler. The pot will be a lot lighter, and you won't have to invest in soil that your plants never utilize.
It's tempting to use your regular garden soil for your container gardens, but don't! Garden soil is far too heavy, does not drain well enough, and may harbor pests and disease. Instead, choose a quality mix labeled as 'potting' or 'container' mix. These types of mixes are formulated to be sterile, drain well, and are much lighter than the soil in your garden. Many mixes available now come with time-release fertilizer incorporated into the mix, as well as moisture retaining polymers which slowly release water to your plants after watering.
You may have pots at home filled with soil from last year's planting. Many people ask me about re-using soil from previous years. The textbook answer is that you should use fresh, new soil mix each year. My opinion is that you certainly may reuse the soil, but do so at your own risk. It is very possible that if there were any disease causing organisms in that soil last year, they are still there this year.
I have attempted to reuse soil from previous years and had very successful results, but I have sentenced more than a few innocent plants to dramatic deaths by soil borne diseases in reused soil. In the long run it is cheaper to just buy new soil each year, rather than risk having to replace all your plants after they die an untimely death due to disease harbored in reused soil.
One of my favorite tips in designing container gardens is that there are three types of plants in a container garden: the thriller, the filler and the spiller. I wish I knew who originally coined these terms, as I think they are a great guideline in choosing plants.
The thriller is the tallest plant in the bunch. It grabs your attention in how it stands above the other plants. The filler is a medium sized plant that dominates the center area of the pot. The spiller cascades down the side of the pot, drawing attention downward.
In my experience, container gardens look best when you have at least one of each of these plants in the mix. Also, odd numbers of plants tend to look best. The pots on my front porch demonstrate this idea. Each pot contains three plants: 'Tricolor' geranium (thriller), Euphorbia 'Diamond Frost' (filler) and bronze sweet potato vine (spiller).
But just because you have a thriller, filler and spiller doesn't mean they look good together. You still have to pay attention to color. This is where many people get frustrated. In my opinion you will have the best results if you keep your color choices simple.
The simplest method is to choose different shades of one color, such as red. Another choice could be a palette of warm colors, which includes red, orange, and yellow. Green, blue, and purple are the cool colors. Warm colors suggest excitement and energy, cool colors evoke peaceful and calm feelings. Choose your favorite.
Complementary colors are colors which lie directly across from each other on the color wheel. These colors bring out the best in each other, and they "pop". Red/green, orange/blue, and yellow/purple are the basic complementary color pairs. Choose plants with these color pairings and you will be very pleased with the results.
A favorite way I choose colors for plants in my containers is to use one plant as a starting point, choosing colors in it to pull out and accent with other plants. We have a grouping of pots in our yard this year that got their color inspiration from the sun-loving coleus cultivar 'Rustic Orange'. This cultivar has shades of orange dominating the leaves, and each leaf is edged in lime green. Plants we chose to build on this color scheme included: orange gerbera daisy, orange portulaca and chartreuse sweet potato vine.
While you are choosing your plants with colors that work well together, keep the plants preferred needs in mind. Choose sun loving plants for sunny locations, shade lovers for shady spots. Do not mix shade loving plants with sun loving plants in the same pot, or one or the other plant will be unhappy no matter where you place it.
If you are trying to choose plants for several containers at once, it can get confusing in a hurry. Group plants for each container together in your cart and ask the cashier to bag or box them together. This increases the likelihood that you'll remember how you wanted to use each of the plants once you get home!