20 of the Best Container Shrubs

All gardeners enjoy the delightful task of potting up spring containers or stretching our summer and spring colour displays by changing out fresh combinations. For the most part, this is small pot gardening. But, one of the most valuable ways in which to use containers is to see them as part of the landscape rather than as isolated decorative items. This is especially useful when planting into the ground is not an option, for it encourages us to plant them up with trees and shrubs as permanent fixtures.  Long-time reader, Clive, set us on the path in search of shrubs and trees for patio containers, and, after filtering out many species, we found a list that covered a few essential pointers for successful containment.

 

Where to use them:

• Place them to filter the wind

• Provide privacy around the patio

• A row of shrubs in containers can create a wall or boundary.

• Group an evergreen with other containers of flowers or foliage, or group several of those evergreens together to create a corner or define a space.

• Their air cooling and cleaning impact are greater too than would be a few small, low-growing arrangements.

 

Plant choices:

Not all plants will grow well in containers; shrubs often stay smaller in a pot than their ground-grown counterparts, though this depends on the plant, climate, and container. 

Characteristics:

• Non-invasive roots

• Can establish roots in a limited amount of soil.

• Compact growth

• Easy to prune – look to multi-stemmed species

• Have moderate water needs; place those in need of frequent watering close to the house.

 

Choosing your container: 

• Plan to re-pot them every other year, allowing for a gradual increase in pot size to accommodate root growth. Repot sooner if you notice roots escaping from the drainage holes.

• Avoid planting into a narrow-necked pot as it is difficult to get a plant out once its roots have spread. 

• A tall, narrow pot is less stable than a squat, low one. 

• Plant tall, narrow plants in wide-based or heavy containers to prevent them being blown over.

• Drainage is critical; add extra holes to ensure good drainage.

• Never reuse a pot without sanitising it first.

 

Healthy plants should be transplanted from nursery pots to containers that are a few inches wider and deeper. 

 

Potting soil:

For a plant, life in a container is much different than one in the ground, and, while containers hold the growing medium and provide necessary drainage, the plants depend on you for ongoing water and nutrients. Keep a space of around 3 cm between the soil and the container rim for watering.

 

Put some quality potting soil in your container. Garden soil is unsuitable as it doesn’t drain well in containers and could be more prone to weeds, insects and diseases. For shrubs, use a soil based potting mix rather than a soil-free mix because it is heavier and will help anchor a bigger plant and its root system. It also helps provide a sturdier base for the container in the wind.

 

Management:

Feeding: Contained shrubs need monthly feeding with a balanced fertiliser during the growing seasons of spring and summer. Keep plants well mulched, and top up regularly.

Watering: a couple of times a week in summer, especially on hot, windy days when they will dry out faster. 

Shaping: Pruning not only shapes the plant it also helps limit or slow down root growth which is important for container plants. Keep trimming away long branches. Use a slanted cut just above an outward facing node. Cut off any dead or dying stems or branches or growth that spoils the shape; keeping only the strongest and straightest lets the plant use its energy for healthy growth and flowers.