Related: Container Gardening
These herbaceous perennials are highly productive and delicious. Catalogs separate strawberries into four groups: June-bearing varieties yield one large crop, ripening in late spring or early summer, depending on the climate. Their all-at-once nature makes June-bearers the preferred choice of those who wish to process the harvest for storage, but less desirable for container gardeners wanting a steady stream of fresh fruits. Everbearing are the most heat-tolerant type, with two crops—one in June and a smaller crop later in summer. Day-neutrals provide multiple flushes of berries from late spring until early autumn. The fruits tend to be smaller than those of June-bearers, but the nearly nonstop harvest extends for months longer. (Some nursery catalogs fail to distinguish between everbearing and day-neutral varieties.) Finally, alpine berries, also called woodland strawberries or fraises des bois, descend from wild strawberries. They are low-maintenance and bear tiny, intensely fragrant fruits from late spring until fall. Alpine strawberries can be tucked among other plants to create a charming window box or hanging basket.
Pot: An 18-inch-wide weatherproof container can accommodate 10 to 12 plants; two can accommodate the 25-plant bunches typically sold. Shallow containers, as little as 10 inches deep, are fine. Pocketed "strawberry pots" can be difficult to keep sufficiently watered, though they do save space.
Soil: Strawberries demand excellent drainage—their crowns rot in wet soil. They also have a very high nutrient demand, however, so give them a rich growing medium, blending 3 parts of a light, friable potting mix with 1 part compost.
Light: Place containers where they receive at least 8 hours of direct sunlight a day. Bright, breezy locations help to thwart fungal diseases.
Water: Because of their shallow roots, strawberries must be watered regularly. Do not allow the plants to become drought-stressed.
Recommended varieties: Select for regional adaptability and taste. Container gardeners should look first to the perpetually fruiting day-neutrals, such as 'Tristar', 'Tribute', or 'Mara des Bois'; or any variety of alpine strawberry. Everbearing varieties 'Ogallala' and 'Ozark Beauty' perform well in hot climates. Because June-bearers yield only one harvest a year, they may not merit the container real estate they demand.
Pruning: Many strawberries put out runners, which divert energy from fruiting to plant production. Unless they are wanted to propagate new plants, remove runners as they appear.
Fertilizer: Apply low-nitrogen fertilizer in early spring, late spring, and midsummer.
Hardiness: Strawberries are suitable for USDA Plant Hardiness Zones 3 through 9, depending on variety.
Caveats: Strawberries are the shortest-lived of these three fruits and may stop bearing in as few as 2 or 3 years. Start with fresh soil and new plants when harvests decline.
Related: Strawberry Growing Guide
Native to much of eastern North America, blueberries are easily grown in containers. In fact, these notoriously acid-loving plants (their ideal soil pH is between 4.5 and 5.5) may be best grown that way in areas with alkaline soil. The fruits ripen from late June to August, depending on the variety and weather. But blueberries are truly four-season plants in the landscape, with bell-like flowers in spring, summer fruits, vivid autumn color, and bright red stems in the winter. Many blueberry varieties require two plants for a good fruit set, and while this means twice the harvest, it may be problematic for small-space gardeners.
Pot: Blueberries are long-lived and develop extensive root systems. Forestall the need to repot with a weatherproof container at least 22 inches in diameter and 18 inches deep.
Soil: Peat-based potting mixes best approximate the acidic conditions that blueberries need. Blend sphagnum peat moss with an equal amount of compost for moisture, fertility, and pH levels.
Light: Place containers where they receive at least 6 hours of bright sunlight daily.
Water: Moisture-loving blueberries require frequent watering, especially in midsummer when the weather is hot and the fruit is ripening.
Recommended varieties: Dozens of varieties are available; select those that are suitable for your climate. In warm regions, 'Sharpblue' is an excellent performer. 'Bluecrop' is recommended for northern areas. Gardeners with limited space should consider dwarf varieties such as Jelly Bean, a 2-foot compact mound, and other self-pollinators like 'Sweetheart'.
Pruning: One-year-old stems bear heaviest. Each year in early spring, remove wood entering its third year to promote new growth. Prune lightly after harvest to shape plants and control their size, if necessary.
Fertilizer: A fertile environment is important. Top-dress containers with a granular fertilizer formulated for acid-loving woody plants in early spring and again in early June.
Hardiness: Blueberries are suitable for Zones 2 through 8, depending on variety.
Related: Blueberries Growing Guide.
Stately and dramatic, fig trees lend Mediterranean flair to any sunny outdoor space. In cold areas, growing figs in containers makes it easier to protect the deciduous plant over winter, and in warm areas, it reins in the plant's legendary vigor. Many figs are root-hardy as far north as Zone 5. The trick to success, however, lies in protecting the delicate buds from winter damage and getting a summer that is long and hot to properly ripen the fruit. Consider positioning the container where the fig can bask in the reflected heat of a south-facing wall.
Pot: By limiting root space, small containers favor fruit production over vegetative growth. Pots as small as 16 inches across and deep are suitable, but the size of the plant you purchase may dictate a larger pot.
Soil: Figs are not finicky about soil, so long as it is well drained. Blend commercial potting mix with an equal amount of topsoil and/or compost.
Light: The best fruit production is in full sun.
Water: Figs are naturally drought-tolerant, but in hot weather, containers dry out rapidly. Water daily in high summer; like most fruits, figs produce best when stress-free. If you're unable to keep your fig amply watered, try using mulch or an automated drip irrigation system, or transplant the tree to a larger container.
Recommended varieties: 'Brown Turkey' and 'Chicago Hardy' are best for cold areas. Warm-climate gardeners have more options, including 'Black Mission' and 'Conadria'. Most varieties bear two crops: an early-summer harvest borne on the previous year's twigs, and a larger, later harvest on new growth.
Pruning: Container figs are best maintained at about 6 feet tall. Shorten the stems after the main harvest. Shortening stems instead of removing them entirely maintains buds to bear next year's early crop.
Fertilizer: Too much fertilizer encourages nonproductive vegetative growth. Top-dress the potting soil with compost and apply a granular woody plant fertilizer early each spring.
Hardiness: Fig varieties vary in their hardiness. The most cold-tolerant can endure Zone 5 winters (with protection). Gardeners in Zones 5 through 7 often employ wrapping techniques, using burlap stuffed with dry leaves or straw, to protect the trunk and branches. Wrapping is not necessary if the fig is overwintered in a cool storage area that doesn't freeze.
Related: Grow Fantastic Figs
The root systems of plants grown in containers are exposed to colder temperatures in winter than they would be if planted in the ground. If a fruit is rated a full zone hardier than the zone where you live, it can be overwintered outdoors in a weatherproof pot. If possible, move the container to a protected spot near a wall or in the ell of a building and shelter it from strong winds and direct sunlight. For extra protection, sink the pot to its rim in a mound of soil, compost, or mulch. Insulate strawberry crowns with a few inches of dry straw. Check the soil for moisture whenever it is not frozen and water if necessary.
A cold but frost-free storage area, such as a root cellar or unheated garage, may be the best winter option, especially for figs, the tenderest of the three fruits.