Container gardening opens up endless possibilities, from transforming a balcony into a green haven to adding structure and colour to patios, courtyards and doorways. But with such a wide range of shapes and sizes available, choosing the right planter can feel overwhelming. Whether you're planting a tree, creating a perennial display, or growing herbs and bedding plants, the size and style of your planter will have a huge impact on plant health and long-term success.

Here’s a simple, practical guide to help you choose the right planter for every type of planting project.

Choosing a Planter for Trees

Growing trees in containers is perfectly achievable—but only if the planter is large and sturdy enough. Trees quickly develop deep and wide root systems, so your planter must give them the space and stability they need.

What size planter does a tree need?

• Minimum 50–60cm diameter for small ornamental trees (e.g., olive, bay, dwarf apple).
  
  

• Larger specimens such as acer, fig or small citrus will appreciate 70cm+ diameter.
  
  

• Depth matters just as much—look for at least 45–60cm deep to accommodate deep root growth.
  
  

Which shape works best?

• Wide, round planters like oak barrels provide stability and generous room for roots.
  
  

• Tapered square or tall planters can work, but ensure they are weighted or heavy enough to resist wind.
  
  

• Cube planters have lots of root space to allow for trees to get a strong foundation. 

Best materials for tree planters

• Genuine oak barrels for rustic durability
  
  

• Large wooden planters (pine or redwood) for breathability and insulation
  
  

• Metal planters for a modern look with excellent strength
  
  

Avoid lightweight, narrow-bottom pots—trees need a solid base to prevent tipping.

Planters for a Perennial Display

Perennials are long-term residents, so they appreciate more space than annual bedding plants. A well-sized planter allows them to root deeply, overwinter safely, and burst back into growth each spring.

Ideal planter size for perennials

• For mixed perennial displays, choose 40–60cm wide planters.
  
  

• Individual, larger plants like hostas or salvias do well in 30–40cm planters.
  
  

• Depth of 30–40cm is usually sufficient for most species.
  
  

Shape considerations

• Troughs and rectangles work brilliantly for mixed perennial displays, allowing you to layer heights and colours.
  
  

• Deep round pots suit specimen perennials that form strong clumps, such as echinacea or ornamental grasses.
  
  

Top tip:

Leave room for growth—perennials spread over time, so starting with a spacious planter helps avoid constant repotting.

Planters for Herbs and Bedding Plants

Herbs, salads and bedding plants are some of the easiest and most rewarding plants to grow in containers. They don’t need as much depth as trees or perennials, but they still benefit from a sensible amount of space.

Recommended sizes

• Herbs: 20–30cm deep; 25–40cm wide for grouped herbs.
  
  

• Bedding plants: 20–30cm deep; width depends on the display—choose something wide enough for a full colour spread.
  
  

• Trailing plants: thrive in bowls, troughs or window boxes with good surface area.
  
  

Best shapes

• Shallow bowls for thyme, oregano and creeping herbs.
  
  

• Trough planters for bedding and mixed herb gardens.
  
  

• Small round pots for individual herbs like basil, mint (kept contained!), or rosemary.
  
  

Material choices

Wooden troughs, are planters.co.uk's top choices for herbs and bedding plants.

Final Tips for Planting Success

No matter what you’re planting, keep these basics in mind:

• Good drainage is essential—ensure your planter has holes.
  
  

• Use high-quality compost suited to the plant type.
  
  

• Allow room for growth—don’t overfill planters with too many plants.
  
  

• Consider weight and stability, especially for larger trees.
  
  

• Match planter style to your garden aesthetic, whether rustic, modern or cottage-inspired.
  
  

Transform Your Space with the Right Planter

Choosing the correct shape and size of planter doesn’t have to be confusing. With a little planning and understanding of your plants’ needs, you can create thriving container displays that bring life, structure and beauty to any outdoor area.

Explore the full range of wooden planters, oak barrel planters, and garden troughs at Planters.co.uk and find the perfect home for your next planting project.