Choosing the Right Plants for a Container Garden

Most plants can be grown in containers: colorful annuals, aromatic herbs, tasty vegetables, exotic tropical plants, hardy perennials, and even some compact shrubs. The choice depends not only on growing conditions—sun, wind, humidity—but also on what you want: a space bursting with color, a gourmet corner, or a haven for biodiversity?

Just like in the ground, each plant should ideally play a role that suits our needs and desires: beautify the space, feed humans or wildlife, provide shade, or perfume the air. Small plants should be doubly useful! By considering both aesthetics (shapes, textures, varied growth habits) and function (nutritious, ecological, sensory), even the most modest pots can be transformed into living mini-gardens full of meaning.

Annual

Annuals are champions of long-lasting blooms: they offer abundant, often fragrant flowers that last from spring until the first frost. Their incredible diversity of colors—both in flowers and foliage—allows you to create vibrant compositions that can be renewed each year. They also play an important role in biodiversity: many species attract bees, butterflies, and hummingbirds. Some plants sold as annuals are actually tender perennials that are not hardy in Canada and are grown in pots for one summer. The main drawbacks? They don’t survive the winter, require annual purchases, and therefore recurring costs and a loss of resources.

Classic flowering annuals: Petunia, pelargonium, begonia, impatiens, zinnia, nasturtium, marigold, cosmos.

Annuals with colorful foliage: Basil, chard, caladium, sea cineraria, coleus, fancy leaf geranium, silver helichrysum, purple oxalis, ornamental sweet potato, red roselle, strobilanthus.

Annuals useful for biodiversity: Cosmos, dwarf sunflower, verbena, salvia, decorative tobacco, calendula.

Annuals for hanging baskets: Lobelia, bidens, diascia, bacopa, calibrachoa, fuchsia, dichondra, lobular, nemesia, verbena, ipomea, petunia, scaevola, sanvitalia, lantana.

Tropical Plants

Tropical plants, with their lush foliage and exotic appearance, quickly transform a balcony or terrace into a little paradise. Some, such as dracaena and fig trees, can even be brought indoors for the winter and live for several years. However, they require more care, particularly in terms of watering and temperature control. It is also possible to move your indoor plants outside during the summer, provided they are properly acclimatized.

Tropical plants for containers: banana, canna, colocasia, alocasia, dracéna, figuier, hibiscus, mandevilla, palmier, papyrus, pothos, tradescantia.

Perennials and Shrubs

In a container garden, perennials and small shrubs provide lasting structure and are a long-term investment. They require less replacement and, if chosen wisely, can bloom every year. The main challenge is overwintering: in pots, their roots are more exposed to frost. It is therefore important to choose hardy species or provide good protection.

Perennials for containers: heuchera, hosta, sedge, carnation, campanula, thyme, alchemilla, bergenia, blue fescue.

Dwarf or compact shrubs for containers: dwarf Japanese maple, spirea, miniature roses, creeping juniper, dwarf willow, cinquefoils, St John’s wort.

Vegetable Plants

Growing vegetables, herbs, and a few fruits in containers combines practicality with pleasure: you get to harvest your crops while beautifying your space. It’s an ideal solution for sunny balconies or terraces. Annual vegetables are well suited to this method, provided they are given good soil, frequent watering, and enough sun. Leafy vegetables, root vegetables, and legumes are easy to sow after the last frost, while tomatoes, peppers, and eggplants require early sowing or seedlings. Some species, such as corn, squash, and melons, are not well suited to container gardening, except for compact varieties. Dwarf varieties, selected for container cultivation, maximize yield.

Climbing vegetables, such as runner beans and cherry tomatoes, are very productive with good support. Manual pollination may be useful in the absence of insects. Easy-to-grow and decorative herbs (thyme, oregano) do well in pots, even with little water.

Strawberry plants, both decorative and productive, are well suited to container cultivation. Some tropical fruits (citrus, figs) can also be grown in pots and overwintered indoors. Hardy fruit trees, on the other hand, are rarely suitable, except in dwarf or columnar versions.

Vegetables for containers: Lettuce, spinach, Swiss chard, kale, celery, fennel, leek, short carrot, radish, turnip, onion, potato, bush bean, climbing bean, pea, cherry tomato, falling tomato, bell pepper, hot pepper, eggplant, compact cucumber, compact zucchini.

Herbs for containers: Basil, parsley, chives, coriander, thyme, oregano, sage, mint (to be isolated in pots), rosemary.

Fruits for containers: strawberry, lemon, dwarf fig.

The Right Plant in the Right Container

Plants that are well suited to growing in pots share several qualities: shallow roots, compact, bushy or trailing growth habit, slow or moderate growth, tolerance to wind, temperature fluctuations and sometimes drought. They also have low nutrient requirements, which makes them easy to care for.

Adapted to Your Conditions

Start by choosing plants according to the amount of light available (full sun, partial shade, or shade). Next, choose plants that tolerate well-drained soil, as most potting soils do. Plants that tolerate dry or moderately moist soil fare better than those that require constant moisture, which is difficult to maintain in pots. Similarly, a certain tolerance to drought is an advantage if watering is irregular. Finally, plants that are low in nutrient requirements are better suited to container growing, as nutrients are quickly washed out. More demanding plants will require regular additions of compost or fertilizer.

Plants for hot, dry locations: Aeonium, agave, brachyscoma, echeveria, California poppy, yarrow, yarrow, scarlet trefoil, poppy grass, purslane, swallowtail.

Flowers in shade: Achimene, bushy begonia, bedding begonia, tuberous begonia, browallie, fuchsia, garden impatiens, erine lobelia, pansy, torenia.

Dimensions

To ensure stability, growth, and harmonious proportions, aim for a mature plant height that is 2 to 3 times the height of the pot. For example, a plant that is 60 to 90 cm (2-3 feet) tall is suitable for a pot that is about 30 cm (12 inches) tall. The plant should not exceed twice the diameter of the pot, unless it has a flexible or drooping habit. When planting several plants in the same container, consider the total width of the plants at maturity to avoid overcrowding. Shrubs and small trees, which are more demanding, require wide and deep pots—ideally at least one-third of the adult height of the plant. For a plant that you want to keep for several seasons, it is best to choose a large pot from the start to limit repotting.

Hardiness

Wintering is the main challenge for potted plants in Quebec. Their roots, which are much more exposed to the cold than those in the ground, are particularly vulnerable. It is generally estimated that a potted plant loses the equivalent of two hardiness zones, but this rule is only a guideline. Even with this precaution, many hardy perennials and shrubs that grow in the ground do not survive the winter in pots, even if they are well insulated with mulch, snow, or protective covers. Survival is therefore always uncertain. It is best to consider container-grown plants as temporary… and rejoice when they make it through the winter.

Arrangements

A container arrangement doesn’t have to be complicated: a few basic principles can guide you, whether you’re aiming for a decorative garden, a food garden, or both. By playing with shapes, colors, and heights, you can easily create compositions that are as beautiful as they are useful.

Color Combinations

The choice of colors for planters depends above all on personal taste. You can opt for a multicolored arrangement, freely mixing shades for a cheerful and vibrant effect, or prefer a monochrome arrangement, focusing on different shades of the same color for an elegant and soothing look. Another option is to use analogous colors—colors that are close together on the color wheel—such as red, pink, and purple, or yellow, orange, and red. To energize a composition, contrasting colors (yellow and purple, blue and orange) create a strong visual impact. In nature, all colors coexist harmoniously. Personally, I don’t worry too much about theory: I just choose colors that I like.

Principle of the “Holy Trinity”

In classic pot arrangements, the “holy trinity” rule is often followed: a focal plant in the center to add height and attract attention, filler plants around the focal plant to create volume, and trailing plants around the edges to soften the composition. This simple but effective approach ensures a pleasing visual balance. Success depends on contrasting shapes, heights, and textures, while respecting the growing conditions common to all the plants chosen (sunlight, watering, soil type). This arrangement works just as well in a round pot as in a rectangular planter, provided that the layout is carefully planned according to the shape of the container.

Feature plants: Agapanthus, citrus, Curaçao milkweed, bamboo, variegated cane, garden dracena, house maple, edible fig, lantana, oleander, New Zealand flax, Paris daisy, African mallow, palm, papyrus, pennisetum.

Filler plants: Agerate, maritime asterisk, hyssop-leaved cuphea, felicium (or blue daisy), South African geranium, heliotrope, bracted immortelle, Dahlberg’s daisy, melampodium, chickweed.

Falling plants: Bacopa, calibrachoa, dichondra, fuchsia, lobelia, lobularia, common ivy, purslane, donkey tail, ornamental sweet potato.

Mixing Vegetables, Herbs and Flowers

Combining vegetables, herbs, and flowers in the same container is not only possible, but highly recommended! This type of mixed cultivation maximizes space while creating attractive, colorful, and lively arrangements. Some edible flowers, such as nasturtiums and borage, add a decorative touch while being useful in the kitchen. Others, such as marigolds and zinnias, help repel certain unwanted insects. Several herbs—basil, mint, thyme, and oregano—give off aromas that can repel unwanted insects and even some small, hungry mammals. In addition to attracting pollinators, this combination of beauty, utility, and protection transforms each pot into a small, nourishing, and resilient ecosystem.

Planting Containers in 10 Steps

Follow these 10 simple steps for successful container planting, whether on a balcony, terrace or backyard.

1. Plan Hardening Off

If your plants come from indoors or from a greenhouse, gradually get them used to the outdoors. Place them in the shade for a few days, then gradually increase their exposure to the sun. Wait until nights are above 10°C (50°F) before leaving them outside permanently.

2. Gather Materials

Make sure you have everything you need within easy reach: potting soil, watering can, tools, fertilizer, gloves, stakes, labels, mosquito netting for drainage, and, of course, your plants.

3. Moisten the Potting Soil

Dry potting soil can repel water. Pour it into a bucket, add a little water and mix until it’s evenly moist, but not soggy. This is a good time to add a slow-release fertilizer, if desired.

4. Prepare the Pots

Clean pots if already used. Cover the drainage hole with a small piece of mosquito netting or newspaper to prevent the potting soil from leaking out. Don’t add a drainage layer to the bottom – it does more harm than good.

5. Partially Fill the Containers

Pour potting soil up to three-quarters of the way into the container, or adjust the amount according to the size of your plant’s root ball. Pack lightly.

6. Remove the Seedlings From Their Pots.

Unstack the plants, holding them by the base and patting the bottom of the pot. For trays, gently separate the roots. Remove any yellow or damaged leaves, and flowers if necessary, so that the plant can concentrate its energy on rooting rather than flowering.

7. Arrange the Plants

Before digging, place the plants on the potting soil to check the visual effect. For a planter that is visible from all sides: place the central plant in the middle, fill in around it, and place trailing plants around the edges. If only visible from one side: place the feature plant at the back, fill in the center, and place trailing plants at the front.

8. Plant!

Dig a hole for each plant, insert it at the right depth, then add potting soil to fill in and stabilize. Pack lightly around each root ball.

9. Water Abundantly

Water thoroughly until the water runs off the bottom of the pot. This ensures that the entire root ball is well moistened.

10. Finish With a Little Pampering

Prune if necessary, and place the planter in the light – but away from full sun for the first few days. Then move it to its final location.