Container Gardening

By Jan Cashman • Posted on May, 1st 2011

Everyone is gardening in containers these days. Small lots and condo living contribute to this trend. People want the ease of planting and caring for a small, ‘contained’ garden. Homeowners are interested in decorating not just the inside of their homes, but also their outdoor living space. Enticing to us gardeners are the beautiful, colorful clay containers being imported from all over the world.

Container gardening has come a long way from a whiskey barrel filled with red geraniums. Beautiful clay pottery is available in all colors, sizes and price ranges from Italy, Vietnam, and Mexico. This year, with the popularity of warm, bright-colored flowers, bright-colored pots are also in vogue. I love the new citrus-colored pots, but I am still partial to simple terra cotta pots with their classic lines. Any plant, any color, will look at home planted in a terra cotta pot.

If it will hold dirt, it will probably hold flowers. I created a funky grouping of plants on my front steps planted in antique tin-ware using an old chair long stripped of its paint to hold one of the tins. Plant in a western hat or boot, hollowed out tree trunk, old worn pail, basket, or old suitcase lined with plastic—all you need are soil and drainage holes. When choosing a container remember, larger pots allow more room for root growth and are easier to keep watered.

Use a commercial potting mix, not soil from the garden, in your containers. Garden soil is too heavy, plus it might contain fungi or insect larvae. A potting mix that is lightened with perlite or vermiculite is good. If the mix contains coconut fiber, even better. Coconut fiber has great water holding capacity. Your container should have holes in the bottom to allow excess water to drain. Use pebbles, or better yet, light styrafoam peanuts, in the bottom of any deep or large container for better drainage.

Due to our low humidity here in the summer, containers need to be watered daily, especially if they are in full sun. We like to mix Soil Moist granules into our potting soil to reduce waterings. Soil Moist is a polymer that absorbs water like a sponge. As the soil dries out, the stored water is released.

Mix slow release Osmocote fertilize into the soil of your containers and you won’t have to fertilize again. Or fertilize with water-soluble Miracle-Gro every ten days.

Choosing plants for your container garden is the fun part, but first you need to know whether your container will be in full sun or partial or full shade. There is a huge selection of plants for any location. Containers can look stunning planted with just one variety of plant but the trend is to use a mixture of plants that compliment each other. Commonly we plant a tall plant in the middle of the pot, with gradually shorter plants toward the edge that will trail over the side of the pot. New and exciting annual grasses such as ornamental corn or millet can be used to give your container-garden height, instead of the over-used spike (dracaena). Two fun and unusual annual grasses that work well in containers are Mexican feather grass which looks and feels like soft green hair and fiber optic grass that looks like fiber optics!

I asked our greenhouse staff what their favorite annual flowers were for planting in containers. They liked million bells petunia, a tiny floriferous, cascading petunia, osteospermum, a daisy-like flower that comes in many colors, and fancy-leafed geranium, a geranium grown primarily for its multi-colored leaves. I like the compact lemon gem marigold; its bright yellow flowers give a splash of color to any sunny container and they will trail over the side as they grow. We all like to mix various leaf-textures in container plantings using interesting herbs such as purple or golden sage or lavender and ornamental grasses.

This year you’ll see containers with lots of colorful and variegated foliage sometimes mixed with complimentary flowers. The new and colorful varieties of coleus combine to make a stunning container garden for shade.

Perennial flowers can be used in containers. Most perennials bloom for a short time and then are done blooming for the season, so tuck in a few longer-blooming annuals and chose perennials with interesting foliage like hostas, lamium, sedum, and pulmonarias. The new shade-loving heucheras and heucherellas are everyone’s favorite and look great in containers. ‘Amber Waves’ heuchera has ruffled golden leaves with pink undersides and contrasts well when planted with ‘Crimson Curls’ heuchera, which has rich burgundy, ruffled-leaves. In the fall you can move the perennials that were in your containers into your perennial garden.

Roses, herbs, vegetables, even trees or evergreens can be planted into containers although the shrubs and trees might not make it through the winter with their roots above ground. Herbs work well in a strawberry pot. In the fall, bring the herbs in the house near a sunny window so you can harvest fresh herbs all winter. My Japanese maple has been growing outside in a pot for four years, but in the winter, we store it in our 35 degree root cellar. Japanese maples cannot survive our winters. Upright junipers, pruned in a topiary shape and planted in an Italian terra cotta container will add a European look to your front entryway.

Funky or formal, colorful or subtle, annuals, perennials, herbs, or evergreens, whichever you choose, plant up a pretty pot or an old trough and add charm to your “outdoor living room”.