Urban gardening 101: How to plant in the space you have

If you want to test out your green thumb, but have very little outside space, fear not: You can still create a green oasis. We talked with Jeff Gilbert, a gardener and marketer for Green City Growers, to learn how to grow a garden in a small space, even if you only have room for one container.

“I think there’s a number of reasons why you would grow your own,” he said. “The value of the produce is one, but also the fact that gardening is an enjoyable thing to do, and that it’s helping you create a little more green space, that’s value in and of itself.”

Whether you have room for a whole garden planted in milk crates—the method used at Fenway Park’s rooftop farm—or just a couple five-gallon buckets on a balcony, here are five tips to get you growing.

1. Find the light

Gilbert said the key to a successful garden is to make sure that fruiting crops (read: tomatoes, eggplant, peppers) get an abundance of daily sunshine.

“In order to grow most crops, you’re going to want at least six to six and a half hours of full sun,” he said.

If your spot doesn’t get that much light, some crops like herbs and leaf lettuces will do fine in as little as four hours of sunshine.

2. Plan your plants

While Gilbert said you can grow pretty much anything other than pumpkins or melons in a small space, you can still choose particular varieties of plants that will help you get the most out of a small area with a more rapid harvest. For example, try cherry tomatoes or Japanese eggplant instead of their regular cousins.

“We tend to grow a lot of varieties of crops that have some smaller fruits,” he said.

3. Give your plants the right space

Make sure you’re giving the vegetables the elbow room they need. While three to five lettuce plants could could fit in a milk crate and grow successfully, Gilbert said a tomato or kale plant would need its own container.

“That’s only because you don’t want your plants competing for nutrients and everything in the soil,” he said. “If you have too many plants condensed into one small spot, none of them are going to grow to full size.”

4. Think about height and depth

When designing your garden, Gilbert advised remembering to plan for the height of the plants to use the light you get best.

“You want to make sure the tallest plants are on the north side of your garden,” he said. “And that’s because the sun, obviously, is moving from east to west across the south side of the sky. So if you were to put a kale plant, which grows to be quite tall, on the north side of the garden, it won’t shade-out smaller plants down below.”

If you don’t have room for depths of 12 to 14 inches—what most fruiting plants require—lettuces and herbs will be fine in shallower soil.

5. Don’t overwater

The best time to water your garden is the morning, Gilbert said, since doing so at night can lead to fungus and mildew problems.

“A lot of people feel like they have to constantly be watering,” he said. “But really what you want to look for is soil that is moist and damp about a finger length down from the surface. You want it to be damp to the touch, not soaking wet. Anything more than that, you’re going to overwater your plants. Anything less, your plants will need more water.”