Yes, using saucers underneath urban planter boxes is highly recommended. They serve a critical function by catching excess water that drains from the pot, protecting your balcony floor, deck, or indoor surface from water damage, stains, and potential rot. Saucers also prevent messy runoff and can provide a small reservoir of water for the plant to absorb later.
The best saucer material depends on your primary need. For durability and weather resistance, plastic or composite polymer saucers are lightweight, inexpensive, and won't rust or crack easily. For a more aesthetic, heavy-duty option, glazed ceramic or concrete saucers are excellent but can be heavier and more fragile. Metal saucers, like galvanized steel, are stylish and sturdy but may rust over time if the coating is compromised.
When selecting a saucer, ensure it is slightly wider than the base of your planter box to effectively catch water. Always check and empty saucers regularly to prevent plants from sitting in stagnant water, which can lead to root rot. For a cleaner look, consider planter boxes with built-in, hidden saucers or water reservoirs.