The ideal olive tree container size starts at 18 to 24 inches (45-60 cm) in diameter for young trees. This gives your olive enough room to grow roots and stay stable in wind. Too small a pot will stunt your tree and cause stress during hot or cold weather.
The pot size for olive trees should grow along with your plant. I started my first olive in a nursery pot and moved it to an 18-inch container in year one. Two years later it went into a 24-inch pot. Now after six seasons it sits in a 30-inch ceramic container and looks great.
Container grown olive trees face challenges that ground-planted ones don't. Roots in pots get hotter in summer and colder in winter than roots in soil. This stress makes your tree need more water and more care. You'll water a potted olive twice as often as one in the ground during hot spells.
Start with an 18-inch pot when you bring home a young tree from the nursery. Move up to a 24-inch container after two to three years of growth. Mature trees do best in pots that measure 24 to 30 inches across. Don't jump to the biggest pot right away since too much soil holds water that can rot roots.
Pot material matters as much as size for olive health. Go with terracotta or ceramic pots instead of plastic. Clay pots breathe and let extra water escape through the walls. Plastic holds moisture too long and can drown roots or cause fungal problems. I lost my second olive to root rot in a plastic pot before I learned this lesson.
Drainage holes are not optional for olive containers. Pick pots with multiple holes in the bottom to let water flow out fast. Add a layer of gravel or pot shards over the holes to stop soil from washing away. Good drainage keeps your olive roots healthy and prevents the soggy conditions they hate.
Weight becomes a factor with larger olive containers. A 30-inch pot filled with soil and tree can weigh over 200 pounds. Put your final container on a wheeled plant caddy if you need to move it for winter or sun. Set up the big pot in its final spot before you fill it with soil and plant your tree.
Pick a container that gives your olive room to grow but doesn't swamp it with excess soil. Move up one pot size at a time as your tree gets bigger. Stick with breathable materials like terracotta that drain well. Your potted olive will thrive for years in the right sized home.
Read the full article: Growing Olives: Step-by-Step Plan for Home Gardeners
