There are about as many reasons to grow plants in containers as there are containers to grow plants in. Container gardening can satisfy whimsy or necessity, and often both at once. The benefits of container gardening far outweigh the few disadvantages—primarily the need to water and fertilize more frequently. Container plants do, after all, completely depend on you.

In areas with harsh winters, container growing allows gardeners to move frost-sensitive plants like citrus to a warm, protected place when chilly weather arrives. When the danger of frost has passed, the sight of blooming, fragrant lemon and orange trees back in their customary garden or patio space announces the arrival of spring.

Plants in containers are easily transportable, across a yard or across country. A new apartment quickly becomes a home with pots of red geraniums on a sunny windowsill. With the addition of drainage holes, old stock pots, buckets or watering cans can be planted with potted chives, basil or sweetly scented flowers to perk up a kitchen or dress up a picnic table.

You can easily move potted plants to redecorate an area, to highlight current bloomers or to protect favorite plants from threatening weather. Plants that are tired or no longer blooming can conveniently be moved out of sight. You can place large containers on casters to roll them from place to place. With the help of container plants in a variety of pots, a small yard can easily become a lush garden.

But even gardeners with plenty of space have reason to plant in containers. As I strolled through a local resort last week, I noted, in addition to the carefully tended beds, other highlights of the landscape. Beautifully shaped and flowering ‘Iceberg' roses in large glazed ceramic pots graced the grounds, while mossy vases of succulents, both upright and trailing, accented exterior walls. Clearly the landscapers resorted to containers not for lack of space, but for an extra touch of interest and elegance.

Container gardening is the epitome of custom gardening. If you know your chosen plants' requirements, you can give each plant just what it needs. Nurseries sell potting mixes designed expressly for orchids, acid-loving plants and citrus. Or you can mix your own to meet a finicky plant's needs, giving you a much greater chance of success.

Some plants actually do better in pots than in the ground. Herbs such as lemon thyme can often become a straggly mat in the garden. In a contained space, lemon thyme grows into an upright mound of attractive, strongly scented, glossy green foliage. By early summer, its lavender flowers drape beautifully over the edges of a pot.

With a properly sized container, the right planting mix, the right location, and sufficient water and nutrients, many plants will be carefree and happy for years. But if you begin to see that your pots are drying out too quickly, or that roots are protruding from drainage holes, or if it takes too long for the water you apply to percolate through the soil, it may be time to repot.

Generally the best time to repot is in the spring or autumn when plants are actively growing. But any time you notice that a plant is too top heavy or that the roots are too dense, it's time to repot.

Container-grown plants are typically fertilized more frequently than plants in beds. If you begin to see a white, crystal-like coating on the exterior of your pots or on the surface of the soil, too much salt has built up in your soil. To avoid salt buildup, always water your plants until liquid runs out the bottom.

Workshop: Have you noticed how popular (and expensive) container succulent gardens are? Do you have a special container you would like to turn into a garden piece? Napa County Master Gardeners will lead a workshop on “Container Gardening and Succulents” on Saturday, May 17, from 9:30 a.m. to 11:30 a.m., at the Senior Multi-Use Center, 2185 Elliott Drive, American Canyon. Grow gardens that are mobile. Discover the best containers, soil and locations for your plants to prosper. Gain confidence to work with unfamiliar types of plants. Online registration (credit card only); Mail in registration (cash or check only).

Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.

 Napa County Master Gardeners welcome the public to visit their demonstration garden at Connolly Ranch on Thursdays, from 10:00 a.m. until noon, except the last Thursday of the month. Connolly Ranch is at 3141 Browns Valley Road at Thompson Avenue in Napa. Enter on Thompson Avenue.