Certain Fig Hybrids
Some species of fruiting fig trees flourish in pots. When placed on a sunny windowsill or outside in warm weather, miniatures like this Ficus carica'Petite Negra' will produce fruits at less than a foot tall. Be sure to keep in mind that plants in containers need water more often than plants in the ground.
Water Lilies
Patios can have ponds, too. Create a water garden in a half whiskey barrel, and grow compact water lilies like this Nymphaea 'Midnight,' whose pint-sized pads and blossoms create instant interest.
Berries
You might expect berry plants to burst out of their confines with Hulk-like power. But with the right variety and the right amount of sun (ideally six or more hours a day), you can grow blueberries, strawberries, or raspberries on your porch, balcony, or patio. Mulberry trees also make great container plants.
Sweet Potatoes
When it comes to ultra-flavorful sweet potatoes, pots aren't just for cooking. Gardening Know How has an excellent tutorial on growing these beloved root veggies in containers. Plant a bush variety (distinguished by shorter vines) in sandy, well-draining soil amended with compost, making sure to space slips 12 inches apart in a clay pot or whiskey barrel with drainage holes. Another plus? The vines' showy foliage!
Celery
Add some crunch to that potato salad with fresh celery (Apium graveolens), whose shallow root system can tolerate pots as small as 8 inches. Place in bright, indirect light, and be sure to keep the soil moist. If you're growing in an unglazed terra-cotta pot, remember that these containers dry out faster than glazed varieties.
Pro tip: Don't discard your celery leaves -- they taste fabulous in pesto!
Hops
Take your garden on a beer crawl. Hops' rhizomes can be grown in a pot at least 20 inches in diameter or in a barrel with several drainage holes. Place in full to part sun, and use potting soil amended with perlite. Train vines to a trellis, and be sure to water and fertilize diligently.
Epiphyllums (aka Orchid Cactus)
These arresting rainforest cacti (that's right, cacti in the rainforest!) actually bloom better when they're root-bound. True to their succulent status, epiphyllums have shallow root systems, so they can be planted closely together in hanging or elevated containers. Give the plants bright, filtered light, plus soil and pots with good drainage. Keep soil moist while taking care not to overwater.
Also, buds fall off easily. So when your plant is approaching bloom time, be sure not to move it!
Meyer Lemon
This citrus isn't just a food-lover's favorite, it's also a plant that can be grown in containers. Place your Meyer lemon plant (whose shrubby habit can be pruned into a tree form) in a large pot with good drainage. Keep in full sun. Maintain moisture and be sure to bring inside if temperatures dip below 10 degrees Celcius.
Japanese Maples
Many Japanese maples (Acer palmatum) are slow growers that do well as container plants. Place your tree in a large container with loam-base compost to ensure good drainage, and feed in spring and early summer.
Ornamental Grasses
Pulled up your lawn in the name of #droughttolerant gardening? Potted ornamental grasses -- like the purple fountaingrass (Pennisetum setaceum'Rubrum') shown here -- can act like punctuation marks in your garden or create an unexpected meadowy mood on your balcony. It's a great way to bring blades of grass to eye level while maintaining a clean look.