Making a Splash with Container Gardens

In areas of drought, container gardens can be an excellent way to grow a few tomatoes and get a splash of color.

Bellium minutum
Item # 25100 		Bellium minutum
Miniature Mat Daisy

each $5.19
3 or more $4.99

Item # 99130 		Zauschneria garrettii 'Orange Carpet'®
Creeping Hummingbird Trumpet

each $6.99
3 to 6 $6.79
7 or more $6.59
Heuchera sanguinea 'Firefly'
Item # 58690 		Heuchera sanguinea 'Firefly'
Coral Bells

each $5.49
3 to 6 $5.29
7 or more $4.99
  • Topic: Container Gardening
  • Keywords: containers, color, small spaces, Planting Techniques, planters
  • Date: May 2002

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Container gardens are becoming more and more indispensable for the harried, the arid, and the space-impaired. In areas of drought, container gardens can be an excellent way to grow a few tomatoes, get a splash of color and satiate your appetite for lush growing things. With a minimum of time, effort and expense, you can show off your green thumb to the world.

There are a lot of reasons to plant in containers. For starters, you can make a garden anywhere—a stairwell, balcony, window, or wall becomes a verdant space with a well-placed planter. You’ll be able to grow plants not generally suited to your soil without employing extensive amendments, or hide unsightly objects in your yard.

Containers make your garden mobile—move your plants into and out of the shade, to the front yard, to the backyard, by the mailbox. They enable you to re-create your garden at will—and if a container plant starts to pass its peak, don’t worry. Just move it into a more concealed area.

Container Choices

What do old boots, antique washing machines and citrus packing crates have in common? You can grow a garden in them! If your tastes run a little less extreme, there are a lot of other options, and very few limitations. The standard caveat is that the containers have drainage holes—but even this isn’t set in stone. If you must use a pot without drainage holes, plant up a smaller pot with holes and place it on a bed of gravel in the larger pot.

Standard terracotta pots have a lot to recommend themselves, but a few drawbacks as well. They breathe, which plants like, but that means watering more often on hot summer days. They are heavier, so taller plants won’t blow over in the wind, but also easily break if they hit the ground. If you are planning to plant year-round containers with hardy perennials, make sure to choose high-fire pots that don’t disintegrate with wet, freezing winter weather. Clay pots are a good choice for succulents, since these plants prefer to stay on the dry side with excellent drainage.

Concrete is a good choice for a heavy planter that’s not likely to be moved often. It can withstand freezing temperatures better than terracotta, and comes in a variety of colors, shapes and sizes.

For plants that need to be more mobile, plastic or fiberglass containers are much lighter, and are beginning to rival terracotta in looks. Generally less expensive, plastic containers also won’t dry out as fast as those made of clay. The main disadvantage of plastic and fiberglass containers is that they are more likely to blow over in windy areas, but you can help prevent this by placing heavy river rock in the bottom when you plant.

Wood is a happy medium in terms of weight and porosity. It has the advantage of insulating the roots from overheating when the summer sun strikes the planter, but it can rot and will need to be replaced every few years. It is possible to line the interior with plastic to slow down deterioration.

In a hot, sunny climate, light colored pots are preferable. They help to reflect heat and prevent the roots from overheating. Black plastic pots and metal planters are a poor choice for hot climates since they absorb heat. If you can place your plants close enough together to decrease the surface area of the pot exposed to the sun this is less of a consideration.

Plant Choices

When electing to garden in containers, you are not limited to just a few old standards—petunias, marigolds and other true-blue annuals. In fact, container gardening has become a huge industry, with many growers putting a lot of effort into finding new, unusual and effective choices to fill your planters. Annuals are, of course, the old standby, and there is always room for a variety of annual favorites. Annuals have the benefit of long blooms and, if kept tidy by deadheading, keep blooming most of the season. But many perennials are starting to find their way into the container garden—along with an acknowledgement that sometimes you don’t want constant bloom—you want the rustle of grasses and the striking foliage of artemisia or yucca.

Any plant can be grown in the right size container. Trees and shrubs, climbers, perennials, ferns and bulbs as well as the more commonly grown annuals and tender perennials should all be a part of your gardening palette.

It helps to establish a theme for your containers, both in terms of design effectiveness and specific plant requirements. If all you have is a shady spot, then use containers full of shade lovers: Lamiastrum, Heuchera, Bellium, Vinca, Aegopodium, Ceratostigma and many others can provide flowering and foliar interest. If your container garden is sunny but windswept use plants that thrive in these conditions: everblooming perennials like “Goodwin Creek” Lavender, “Raspberry Delight” Salvia, and Pink Texas Skullcap are showy and tough. Silky Threadgrass (Stipa) adds texture and movement to any full sun container. If you need height try climbers. Our Rosa x “John Cabot” is an excellent choice for containers as it is a repeat bloomer, has a vigorous climbing growth habit and is extremely cold hardy.

If you’re aiming for a low-water solution, choose more xeric plants such as Santolina, Tanacetum and Artemisia for foliage; for flowering interest as well as architectural appeal, look to favorites like the Salvia pachyphylla, Amphora canescens, and Petalostemon purpurea. My absolute favorites for trailers in container gardens are the Rosmarinus officinalis “Irene” and Origanum libanoticum. Separate water-thirsty herbs like basil from more drought-tolerant herbs like rosemary. This bears repeating: no matter the theme, always always always plant with Broadleaf P-4 water retention crystals!

Many people enjoy using tender tropicals like bougainvillea, brugmansia, oleander and hibiscus in their outdoor summer gardens, and then bringing them in during the winter. Remember that any plant you take outside will require a lot more water than it needed in the house.

Quick Design Tips

Try mixing plants with many (at least three) different textures of foliage to make it interesting even when there are no blooms, and use plenty of plants just for their foliage in your designs.

Use colorful foliage like Coleus, Artemisia or Sedum “Arthur Branch” to draw out the color of flowers in the container.

Plant to attract hummingbirds. Containers filled with Agastache aurantiaca cultivars “Shades of Orange” and “Just Peachy”, Salvia x “Raspberry Delight” and Zauschneria garrettii “Orange Carpet” will bloom for months and provide a less labor intensive alternative to hummingbird feeders.

Containers look best in groupings. Unless you are using especially decorative pots that you want to show off in addition to the plantings, group plants together—this allows for more dimensional variations.

Rules for Planting

With annuals, the rule is to pack them in tightly, making an instant show. Root masses should be nearly touching each other to create a full display right away—if some plants aren’t thriving in this arrangement, replace or remove a few. Remember that when plants are packed in this tightly there is little room for water or nutrients. Pay close attention—water and fertilize regularly.

When using perennials in containers, don’t pack too tightly, and don’t use a larger container than the root ball warrants. When the root ball reaches the sides and begins to mat, move the plants to containers one or two sizes larger. Note: if you are planting with perennials and will be leaving the containers outside for winter, make sure that the plant’s hardiness rating is one zone below your own, as it will be more exposed in the pot.

Plant up the containers using a good quality soil-less potting mix. Yum Yum Mix or a time release fertilizer should be blended into the potting soil along with P-4 water retention crystals. Don’t fill pots with soil from your garden. It will compact and suffocate plant roots. Water well with our Root Stimulator Combo pack (liquid seaweed and SuperThrive) when planting. Mix this combo with a water soluble fertilizer (liquid Gro Power or Miracle Grow) and apply to the containers on a regular basis as they grow. Remember that the plant’s roots can’t wander far and wide to find nutrients—you should make sure to provide the proper conditions and the food and water they need.