Best Plants For Raised Beds And Grow Boxes

Both grow boxes and raised beds provide effective solutions for a variety of plants that thrive in controlled environments. Choosing the right plants for your grow box or raised bed depends on several important factors:

 Height of Your Raised Bed 

Shallow-rooted crops are best suited for a raised bed about 8 inches (20 cm) in height, equivalent to the height of one concrete block. If you plan to grow deep-rooted crops, you can construct a deeper box by stacking concrete blocks on top of each other. This guideline applies regardless of the materials used to build your grow box or raised bed.

Best plants for raised bed that is shallow (8-11 inches deep)

Leafy greens: lettuce, pak choi, kale, cabbage, spinach, mustard greens
Cruciferous vegetables: broccoli, cauliflower, brussel sprouts
Herbs: basil, parsley, cilantro, mint, rosemary, chives and thyme.
Root vegetables: beets, radishes, green onions, baby carrots.
Ornamental plants: marigolds, petunias, impatiens, zinnias, creeping thyme.

Best plants for raised bed that is at least 12-18 inches deep

Leafy greens: lettuce, pak choi, kale, cabbage, spinach, mustard greens
Cruciferous vegetables: broccoli, cauliflower, brussel sprouts
Herbs: basil, parsley, cilantro, mint, rosemary, chives and thyme.
Fruit-bearing vegetables: tomatoes, peppers, cucumbers, ochroes, eggplants, peas, beans.
Root vegetables: beets, radishes, turnips, green onions, carrots.
Ornamental plants: marigolds, petunias, impatiens, zinnias, creeping thyme pansies.

Best plants for raised bed that is at least 24 inches deep

Leafy greens: lettuce, pak choi, kale, cabbage, spinach, mustard greens
Cruciferous vegetables: broccoli, cauliflower, brussel sprouts
Herbs: basil, parsley, cilantro, mint, rosemary, chives and thyme.
Fruit-bearing vegetables: tomatoes, peppers, cucumbers, ochroes, eggplants, peas, beans, okra.
Root vegetables: beets, radishes, turnips, green onions, carrots, turnips.
Tubers: potatoes, sweet potatoes, yams, cassava, taro
Ornamental plants: marigolds, petunias, impatiens, zinnias, creeping thyme pansies.

Amount of Sunlight

When choosing plants and determining the best spots for each type, consider how much sunlight the area receives throughout the day. Here are the guidelines based on sunlight exposure.

Full Sunlight (6-8 hours of direct sunlight).

Fruit-bearing vegetables: tomatoes, peppers, corn, cucumbers, squash, eggplants, melons, pumpkins, peas, beans, okra.
Herbs: basil, rosemary, thyme, oregano, sage
Ornamental plants: Sunflowers, marigolds, zinnias, geraniums, petunias, roses, lavender

Partial Shade (3-6 hours of direct sunlight): 

Leafy greens: lettuce, pak choi, kale, cabbage, spinach, mustard greens
Herbs: chives, parsley, mint, cilantro
Ornamental plants: impatiens, begonias, ferns, bleeding hearts, coral bells, hostas, poinsettias

Full shade(less than 3 hours of direct sunlight):

Leafy greens: lettuce (loose leaf, butterhead, romaine), spinach
Herbs: chives, mint
Ornamental plants: Hydrengeas, camellias, rhododendrons, azaleas
This structure should help clarify your plant choices based on sunlight exposure!

Material Used 

The type of material used to construct your raised bed can significantly affect the overall health of your plants. Materials such as metal and concrete can influence soil temperature, which is crucial for the types of plants you select.

Heat-tolerant plants

These plants are well-suited for high soil temperatures. To help your plants manage elevated temperatures more effectively, it's essential to ensure consistent watering, apply mulch, and maintain proper drainage.
Fruit-bearing vegetables: tomatoes, peppers, corn, cucumbers, squash, eggplants, melons, pumpkins, peas, beans, okra.
Herbs: basil, rosemary, thyme, oregano, sage
Ornamental plants: sunflowers, lantanas, portulaca, zinnias, marigolds 

Soil Mix

The type and composition of soil mixes used in raised beds are crucial for plant growth and health. In contrast, soil-less growing mediums or mixes used in grow boxes allow for precise control of nutrient levels because they do not naturally contain nutrients and rely on externally applied nutrients.
 
With this in mind, you can successfully grow a wide range of crops and ornamental plants in raised beds by using a well-balanced soil mix and regularly replenishing nutrients. For grow boxes, the soil-less growing medium supports various plants by utilizing balanced nutrient solutions tailored to the specific needs of the plants you are cultivating.

 Companion Planting

Utilizing companion planting in your grow boxes or raised beds can lead to a highly productive garden space. This technique fosters a symbiotic environment that enhances the overall health of your garden. Companion planting can create shade for neighboring plants, improve nutrient availability, and, in some cases, repel insects. Below are some companion plants that work well in grow boxes and raised beds.

Vegetables:

Tomatoes can be paired with peppers, carrots, lettuce, onions, basil, and various herbs. 
Cucumbers can accompany peas, beans, radishes, and marigolds. 
Lettuce works well with cucumbers, carrots, radishes, and strawberries. 
Beans thrive alongside corn, radishes, squash, and marigolds. 
Peppers go well with tomatoes, basil, and spinach. 
Spinach can be combined with carrots, peas, radishes, and strawberries.
Okra with tomatoes, lettuce, cucumbers, peppers, beans
Beets with lettuce, garlic, onions, mint, marigolds
Eggplants with tomatoes, peppers, beans, spinach, lettuce, basil, marigold.

Herbs:

Chives can be grown with carrots, tomatoes, lettuce, cabbage, peppers, and other herbs. 
Thyme pairs well with cabbage, tomatoes, and strawberries. 
Parsley can be grown alongside chives and thyme.

Ornamentals

Roses grow well with chives. 
Marigolds pair nicely with tomatoes, peppers, cucumbers, beans, squash, and carrots.
 Impatiens thrive alongside ferns, hostas, begonias, coleus, and caladiums. 
Zinnias are compatible with tomatoes, peppers, cucumbers, basil, mint, thyme, marigolds, and sunflowers. 
Sunflowers flourish with corn, cucumbers, tomatoes, peppers, beans, marigolds, mint, and basil.

Type of Garden and Personal Plant Preferences

Consider the specific crops or ornamental plants you enjoy, and decide whether you would like to create a vegetable, herb, ornamental, or mixed garden. Once you have chosen the type of garden you want, simply follow the guidelines provided above to create a productive and efficient raised bed or grow box garden.

By keeping these factors in mind, you can select the most suitable plants for your gardening setup.