The urban gardener’s biggest challenge is successfully growing flowers and vegetables in a soil less environment. Whether it’s a rooftop, a balcony, a driveway, or an inhospitable area, it’s clear that conditions aren’t optimal. Let’s give ourselves the best possible chance—starting with the choice of containers.
Oh, how pretty are those images we see online: a beautiful staircase where each step holds its own little pot of hot peppers. However, the experienced gardener will immediately spot the flaw in such an arrangement: watering. Few gardeners dream of watering those tiny containers three or four times a day, as they dry out almost as soon as they get wet. On a balcony, to make your life easier, bigger is better.
Grow More Together
Therefore, you should opt for the largest possible containers. Rather than growing tomatoes in one pot, basil in a small planter, and chives in a third container, it’s better to combine everything in a single large container. This way, the greater volume of potting soil retains moisture more easily.
The Largest Possible Diameter
Look for containers larger than 30 cm (12 inches) in diameter to obtain a decent volume of potting soil. Also consider building a raised bed—a large wooden box placed on four sturdy legs. This last solution is the ideal setup for achieving generous production with no more than one watering per day.
Have Depth
The same goes for the depth of the containers, which should ideally be 20 to 30 cm high (8 to 12 inches). This corresponds to the average depth roots reach into the soil. If the container is much deeper, it’s perfectly fine to fill the bottom with reused polystyrene boxes or any other lightweight material, then top it off with good potting soil.
Always With Drainage Holes!
Then, the third point to look out for is the presence of drainage holes. Trapping water in the container—thinking it will reduce watering frequency—is not a viable option, except for a few aromatic plants with aquatic ancestors. For the survival of most plants, it’s essential that excess water can drain away.
Of course, the larger the container, the heavier it is to move in spring and fall. Luckily, there are plenty of options—starting with the popular fabric containers, which offer good durability and can be folded and stored on a shelf. It’s also worth noting the lightness of plastic containers, which come in a wide variety of styles, including some surprisingly convincing terracotta imitations.
Let’s not forget that the market also offers containers with automatic watering systems or closed-loop water circulation. In these cases, container size matters less than when watering is done manually. These are great options for gardeners seeking more autonomy.
The exterior of the pot is also important. Terracotta and wine barrels are well insulated. Black vinyl nursery ‘pots’ though, can get hot where exposed to sunlight. They can work out nicely if some sort of vegetation cascades outward and downward over their exteriors while the weather is still cool during spring (before the weather gets warm during summer.) Nasturtiums, trailing rosemary and even strawberries work nicely. Strawberries may not reach the ground, but they extend their foliage out enough to shade their pots from above.
Great tips!