How to Garden on an Island

Container Gardening

Container gardening is an easy way to garden when ground space isn’t available. Perhaps you are faced with a courtyard without planting areas. Or, you have a second story patio where you desire some greenery. Container planting includes pots sitting on a patio, window boxes, and hanging baskets.  Pots are wonderful in that they are portable- you can move them around to accommodate your needs. Historically, the French used pots to grow their citrus trees so that they could move them into greenhouses in the cold months. For all the flexibility that container gardening has to offer, there are a few tips that might help you to achieve the perfect potted plant environment.

The Island Effect: When clients tell me they want to include some containers with plants in their garden, I remind them that potted plants are isolated like an island. They cannot draw nutrients from the adjacent soil. They cannot suck up water from their neighbors either. Therefore, any water or nutrients that the plants receive must be given by you, the gardener.  For irrigation, either the pots can be hand-watered or drip irrigation tubing can be installed. The tubes are very flexible and can be hooked up to the automatic irrigation system that you may have already. The nutrients will come from the potting soil and any fertilizer that you may add periodically. Because the pots are exposed to the elements on all sides, they will be the first thing in the garden to feel the heat and the cold. On really hot days, plants may need to be watered twice daily; on very cold nights, you may need to protect the plants from frost with netting or similar coverings.

The Container: There are several different kinds of pots that can be used for plants. Conventional pots are made of clay, plastic, or metal. Local gardening nurseries and home improvement stores have an abundant selection. Personally, I shop at Canyon Pottery in Kearny  Mesa (www.canyonpottery.com).  They offer wholesale prices to the public and have a great selection. Other favorites of mine are the Madd Potter (www.maddpotter.com) and Cordova Gardens, both in Encinitas.

Whatever pot you choose, make sure there are holes in the bottom for adequate drainage. If the pot is over 12” tall, then add drainage rock a few inches deep at the bottom of the pot.  Otherwise, the weight of the soil will clog the holes and the plants will rot and die. The drainage rock can be any rocks that are 1”-3” wide.

Saucers or Feet: There are two different ways to address the bottom of the pot. One is to place a saucer under the pot to collect the water that drips out of the pot. This is a good solution if you are concerned about stains on the pavement underneath the pot. The saucer may need to be emptied occasionally of overflow water. Sometimes the standing water can attract pests and fungus and look unsightly. Alternatively, the pots can be elevated using “feet.” They can be decorative and part of the overall look, or they can be hidden under the pot and out of view. The pot can be off of the ground and allow air circulation under the pot. You may find drips of the water from the pot, but it can be washed away with a hose or a good rain.

The Soil: Use soil that is specifically labeled as Potting Soil. This soil is designed for containers and contains perlite or vermiculite which provides air space. If regular soil is used, it will compact over time and your plants will decline. If you are planting succulents, then use a potting soil that is labeled for succulents. This soil has added sand which will allow very fast drainage - essential for succulent plants’ health.

The Plants:  There are numerous plants that are suitable for containers: annuals, perennial, edibles, succulents, woody plants and bulbs. Whatever you decide to plant, pay attention to the plant as its needs will be immediately evident.  One day the plant is fine, and the next it is dire need of water. As far as design, if I am creating a container with multiple plants, I like to have one foundation plant as an anchor. This might be an evergreen shrub or succulent that will look good most of the year. Then I add other plants for added visual interest.  Below is an example of a container planting that I completed recently. The Phormium (New Zealand Flax) served as the anchor plant and then the Echeveria ‘Afterglow’ was added as support. I chose the boxy black containers to support the modern design of the client’s architecture.

The photo below shows another container planting where Euphorbia tirucalli (Sticks on Fire) served as the anchor plant.  I added the grass for its texture and its movement in the wind. The Sedum was added as a creeping ground cover to fill in the gaps.

Container planting can a great way to experiment with small scale gardening. Its portability can offer the flexibility that you might be seeking in your garden. Container gardening is not for the absent gardener, but for those who are willing to be attentive, it can be very rewarding.