That's an excellent question! The number of plants you can realistically fit in one of our larger urban planter boxes depends less on a strict count and more on giving each plant the space it needs to thrive. Overcrowding leads to competition for water, nutrients, and light, resulting in weaker plants. Here’s a practical guide based on the mature size of your plants.
For our larger boxes (typically 24-36 inches long), use the "one plant per square foot" rule as a starting point for medium-sized plants. For example, you could comfortably grow 2-3 tomato plants, 4-6 pepper plants, or a mix of 8-12 leafy greens like lettuce or spinach.
For herbs and small flowers, you can plant more densely. You might fit 4-5 basil plants, 6-8 thyme or oregano plants, or a vibrant cluster of 10-15 marigolds or pansies in one box.
The key is to always check the spacing requirements on your seed packet or plant tag. Consider companion planting—pairing deep-rooted vegetables with shallow-rooted greens, for instance—to maximize yield. With thoughtful planning, our larger planter boxes can support a surprisingly abundant and healthy mini-garden on your patio, balcony, or rooftop.