Regional Gardening Reports :: National Gardening Association

In the Garden:
Northern California Coastal & Inland Valleys
March, 2011
Regional Report

Share |

Visit the Conservatory in Golden Gate Park for a beautiful display of container plants.

Gone to Pot

Much of my gardening is done in containers. The deck at Henry's home contains dozens of roses, fuchsias, hydrangeas, aspidistra, and a host of other plants that are well suited to being grown in pots. Henry has it all set up with an elaborate drip system, but I like to supplement with water from the hose when the weather turns warm, much to his dismay. I figure the proof is in the pudding. Last year we had a beautiful display of colorful container plants. Had we relied on his drip system we would have seen brown edges, wilted foliage, and many less blooms.

Getting Started
The first thing you will need is a container. Bigger is better because a larger pot holds more soil, which provides room for the roots to grow.
Plastic, wood, or terra-cotta are all excellent materials for container gardening, and each has its strengths and downsides. Plastic is inexpensive and light in weight, but tends to hold moisture longer and doesn't wick out minerals from the water. Wood is natural and will eventually decompose. It dries out quickly, which is good for plants that require drying out between watering such as cactus and some succulents. Terra-cotta is expensive and fragile and dries out more quickly than plastic, but it has that beautiful "look." If you would like to see a gorgeous display of antique containers, visit The Conservatory in Golden Gate Park.

Annuals or Perennials?
Annual plants don't need as much depth of soil as perennial plants. The roots of most annuals only grow down about 8 inches into the soil. That means you can select shallow, bowl shaped containers to display plants such as pansies, petunias, and lobelia. Perennials, on the other hand, require more room for the roots to grow. Rudbeckia, chrysanthemum, and campanula all require deep soil. Dahlias, for example, should always be planted in a deep container.

The problem with planting perennials in containers is that there will be a period of time when your pot will appear empty, especially with bulbous plants or plants such as delphinium that go dormant during the cold weather. Over-planting with annuals is one way to utilize the container while the perennial is "resting." Pansies or primroses will provide color until the main show gets underway later in the season.

Shrubs and Trees in Containers
Planting a more permanent display can be achieved by selecting some well mannered shrubs and small trees. Citrus does especially well in containers but needs to be kept continuously moist throughout the growing season. Lavender is another plant that does beautifully in containers so long as you provide fast draining soil. Japanese maples (Acer japonicum) make stunning container specimens as do yesterday-today-and-tomorrow(Brunfelsia spp. ) and hibiscus. Fussy plants that require special care such as gardenia and daphne do particularly well in pots where their specific planting needs can be addressed.

Green foliage plants such as boxwood (Buxus spp.), acuba, aspidistra, and fatsia make excellent background plants for showier specimens. Foliage plants arranged in groups give a formal look to a patio or deck.

Top dressing with compost in the spring will keep the soil fresh and nutritious for your permanent guests. However, plants grown in containers will eventually require transplanting. Large plants can be slipped out of their pots for periodic maintenance and root inspections. Lay the container on its side, slip a long bladed knife around the outside of the root ball to loosen it from the sides of the pot, then gently slide it out.

Lightly trim the outer roots, then add a few inches of soil to the bottom of the pot, set the plant back inside and fill in around the sides with fresh potting soil, leaving room at the top to water. This is basically a bonsai technique, but it works well for large plants that have indicated by dropping lower leaves that they are ready for a rejuvenating treatment.

I have successfully grown sweet peas in pots. They are extremely deep rooted and require a very large vessel. They are also very thirsty and very heavy feeders, so be prepared to be a slave to them while they are actively growing.

If you haven't tried container gardening, give it a shot. Vegetables, flowers, shrubs, trees - there's a whole world out there waiting to bloom at your doorstep. After all, how do you think the strawberry pot got its name?

Care to share your gardening thoughts, insights, triumphs, or disappointments with your fellow gardening enthusiasts? Join the lively discussions on our FaceBook page and receive free daily tips!


Today's site banner is by sunnyvalley and is called "Iris Eternal Bliss"