Urban Gardening Secrets

Urban Gardening: Windowsills, Rooftops & Balconies

Even if you live in an apartment in the middle of an urban canyon, don’t despair — you can still garden. It just takes a little creativity to find and use windowsills, rooftops, balconies, and community gardens to grow lush vegetables, flowers, and herbs.

Containers with holes for good drainage and locations with six hours of sun per day are essential partners in urban gardening.

It’s hard to get enough light to grow food crops on an indoor windowsill. Glass provides enough UV protection to keep the light from being strong enough. Grow-lights are a better solution indoors because they provide the right light spectrum plants need to grow.
Learn more about plant grow lights.

A windowsill does provide enough light to support many herbs and houseplants, such as parsley, begonia, coleus, hoya, and Swedish ivy. Most flowering plants need bright, indirect sunlight to bloom. Research how much light your plants need when choosing plants and where to place them.

Rooftops and balconies are better venues for growing vegetables and herbs than windowsills because they offer plants more light, plus access to rainwater. In these locations, container gardens rule.

Learn how to garden smarter in the heat of Arizona.

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Urban Gardening: Deep Containers

To grow vegetables on a rooftop or balcony, choose a container 14-18 inches deep. If you are growing vegetables with deep roots, such as potatoes and tomatoes, choose a container at least 18 inches deep.
Get ideas for growing vegetables in containers.

With all containers, monitor soil moisture; too much or too little water can cause problems. When growing most flowers and vegetables, allow the top 1-2 inches of soil to dry out before watering. Drought stresses plants, and overwatering kills them.
Learn more about growing vegetables in containers.

Learn about different types of containers.

Self-watering containers are a good choice for rooftop gardens where hot sun can create baking conditions.

Dark-color pots absorb more heat than light-color ones and may get so hot that root systems are injured. Succulents and natives of hot, dry areas do best in these conditions. To alleviate the problem, move dark pots to areas that receive shade during the hottest parts of the day, add trailing plants to shade the pot, or devise screening.

Even if your budget doesn’t allow for the purchase of beautiful new containers, you can use any number of easily acquired items, such as plastic buckets, children’s wading pools, crates, whiskey barrels, and bricks or concrete blocks stacked in a container shape. Just be sure that your container has multiple holes to allow water to drain from the bottom. Avoid using chemically treated wood, which may have toxins that can kill plants.

Try a repurposed container.

If your containers are housed in a windy area, such as a balcony, choose a container with straight sides for stability. Any pot with a base that’s smaller than the top opening is more likely to be blown over in a stiff wind, especially small pots with less weight.

All containers, including window boxes, should contain a lightweight potting soil or soilless mix. Garden soil is too heavy for container use and leads to compacted roots and poor drainage.

Make your own potting mix.

Urban Gardening: Window Boxes

A window box with access for planting, weeding, watering, and harvesting can be an effective form of urban gardening. Because a window box usually isn’t deep enough to support the deeper root systems of many vegetable plants, choose smaller plants such as parsley, basil, and other herbs.

Microgreens, spinach, lettuces, and other vegetables meant to be harvested as miniatures also make good window box options. Try combining herbs with flowering annuals for a beautiful display, choosing some that will trail over the edge of the window box. Most plants will do best if the window box receives at least 4-6 hours of sunlight per day.

Create a sunny window box garden.

Grow a window box garden in shade.

Grow herbs.

Urban Gardening: Go Vertical

Urban gardens may not have acres of ground for planting but they can always grow up. Walls, trellises, and hanging baskets extend the growing area vertically.

Use posts or walls with brackets to support hanging baskets of herbs or flowers.

Large containers can be topped with a trellis, obelisk, or tomato cage for extra growing space. Pole beans trained on a trellis or obelisk are a good choice for urban gardening because they continue producing beans throughout the growing season instead of one flush at the beginning and one at the end. Tomato plants, with their long limbs and heavy fruits, benefit from the extra support from a cage. Almost any veining plant grows well on a trellis. Add slings or other supports for heavy fruits such as melons. Other veining crops to grow on trellises include climbing peas, cucumbers, pumpkins (but not the giant kind!), and squash.

Small trees can be grown in very large containers (at least 10-15 gallons), including types bred to stay short and columnar. If you choose to grow a columnar apple tree, check to see if it will self-pollinate. Many apple trees need at least one other apple tree for fertilization.

Urban Gardening: Community Gardens

As growing your own food and flowers becomes ever more popular, many people carve out community garden spaces in unused lots, school yards, and other public properties.

Search for community garden space near you by contacting the American Community Garden Association (acga.localharvest.org) or your local cooperative extension service.

To start your own community garden, collaborate with like-minded people on a plan for how plots will be planted, tended, and harvested, and about rules such as whether the garden will be organic or allow chemicals.

Choose a site that receives at least 6-8 hours of direct sunlight per day, and get the soil tested before starting to be sure it will support gardens.

Get tips for starting a vegetable garden.

Urban Gardening: Succession Planting

To get the most vegetables out of a small plot or large containers, try succession planting. This means planting vegetables that ripen in sequence, choosing varieties with short maturation times, and staggering the planting times.

Because most vegetables have a short harvest window (indeterminate tomatoes and pole beans are exceptions), sow a new round of seeds or plants every two weeks to continually harvest your favorites.

Divide your growing area into three sections, or use three containers, planting in one of them every two weeks.

You can also share some spaces. For example, begin the season by planting vegetables that thrive in cooler weather, such as lettuce, radishes, kale, beets, collards, peas, and spinach. As each cool crop ends, plant warm-season vegetables in its place, such as beans, eggplant, peppers, squash, tomatoes, and others, continuing successive plantings with the change of seasons.

Learn more about succession planting.

See our collection of container recipes!

Get inspiration for a gorgeous city landscape.

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