For roses, depth is more important than width when it comes to pot size. Here’s why:

• Deep Root Systems: Roses have deep, extensive root systems that need room to grow downwards. A deep pot allows the roots to spread out and access water and nutrients effectively.   

  
• Drainage: Depth also plays a role in drainage. A deeper pot with drainage holes helps prevent waterlogging, which can be detrimental to roses.   

Here’s what to consider when choosing a pot for roses:

• Minimum Depth: Aim for a pot that is at least 18-24 inches (45-60 cm) deep. This provides enough space for most rose varieties.
• Width: While width is important, it’s secondary to depth. Choose a pot that is at least 18 inches (45 cm) wide to provide stability and some room for lateral root growth.
• Pot Size and Rose Type: Different rose types have varying root system sizes. Miniature roses can thrive in smaller pots (around 12-15 inches deep), while larger varieties like hybrid teas or floribundas will need bigger pots (20-24 inches deep or more).
• Material: Choose a pot made from durable materials like terracotta, ceramic, or heavy plastic. Ensure it has drainage holes at the bottom.
• Drainage: Proper drainage is crucial for roses. Use a well-draining potting mix and consider adding a layer of gravel or pebbles at the bottom of the pot to improve drainage.   

Here are some recommendations:

• For miniature roses: A pot that is at least 12-15 inches (30-38 cm) deep and wide.
• For hybrid tea roses: A pot that is at least 20-24 inches (50-60 cm) deep and wide.
• For climbing roses: A pot that is at least 2 feet (60 cm) deep and 2 feet (60 cm) wide.   

Remember these points:

• Bigger is generally better: When in doubt, choose a larger pot. It’s better to have a pot that is slightly too big than one that is too small.
• Repotting: As your rose grows, you may need to repot it into a larger container every few years.   
  
• Watering: Roses in pots will need more frequent watering than those grown in the ground. Check the soil moisture regularly and water deeply when needed.   

By choosing the right pot size and providing proper care, you can successfully grow beautiful roses in containers!