Raised beds, containers, cedar planter boxes: who can tell the difference when there are so many options out there? To keep things simple, let’s go with the most common definitions.
A raised garden bed is a large frame that sits directly on the ground with its bottom open to the soil beneath. A planter box has a solid bottom that sits on four or more legs, raising it off the ground. Both options let you grow an abundance of food and flowers, though raised beds tend to be larger, with more soil volume. Learn more with our planter box ideas for backyard growing.
Planter boxes are a great way to grow flowers, herbs, vegetables, and other plants if you have limited yard space. With the right soil, plants, and care, anyone can have a successful container garden in planter boxes – even beginners!
In this detailed guide, I’ll walk you through everything you need to know to plant your first planter box garden, including:
- Choosing the right planter box
- Picking the best soil
- Deciding what to plant
- Planting your plants
- Caring for your planter box garden
Follow these simple steps and you’ll be on your way to growing fresh fruits, veggies and herbs on your patio or balcony
Choosing the Right Planter Box
The first step is selecting the right planter box for your space Here are some tips
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Consider the size – Planter boxes range from small (2 feet long) to large (4 feet or longer) Make sure to pick a size that will fit in the space you have. Bigger is not always better with planter boxes
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Material matters – Cedar and redwood are popular natural wood choices that last. You can also find planter boxes made from metal, plastic, concrete and other materials.
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Ensure adequate drainage – Holes in the bottom of the planter are needed for excess water to drain out.
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Add wheels – Wheeled stands make it easier to move heavy planter boxes.
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Match shapes to space – In addition to basic rectangle planter boxes, you can also find L-shaped, U-shaped and tiered options.
For my first planter box, I chose a 3 foot long cedar box with drainage holes and wheels. This provides enough space for veggies and herbs without taking up my entire balcony.
Picking the Best Soil
Now that you have your planter box, it’s time to add soil.
Do not use garden soil!
Planter boxes need a lightweight, porous potting mix that drains well.
Here are some tips for choosing the best soil:
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Look for mixes made for containers – These are blended for drainage and moisture retention. I like using organic potting mixes.
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Incorporate compost – Compost adds nutrients and helps retain some moisture. Mix in up to 30% compost with your potting soil.
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Consider soil amendments – You can also add perlite or vermiculite to improve drainage and aeration.
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Fertilize at planting – Mix in a granular, organic vegetable fertilizer when first planting.
For my planter box, I used an organic potting mix amended with compost and an organic vegetable fertilizer. The soil fills my planter box about 1-2 inches from the top.
Deciding What to Plant
Now for the fun part – picking plants! Consider the following when making your selections:
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Sunlight needs – Pick sun-lovers like tomatoes and peppers if you get 6+ hours of sun. Choose lettuce, kale and herbs for shadier spots.
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Plant sizes – Dwarf or patio varieties are best for fitting more plants in a planter box. Check plant tags.
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Mix edibles and flowers – Add marigolds, nasturtiums or other flowers to attract pollinators.
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Choose what you like to eat – Plant fruits, veggies and herbs you enjoy eating!
Here’s what I chose for my first planter box:
- 3 patio tomato plants (1 each of 3 varieties)
- 1 jalapeno pepper
- Basil, oregano, thyme herbs
- Lettuce
- Marigolds and nasturtiums
This will give me a mix of vegetables and herbs I love with some pretty flowers mixed in.
Planting Your Planter Box
Now comes the fun part – planting! Follow these tips for planting success:
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Follow spacing guidelines on plant tags or seed packets. Plants need enough room to grow.
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Arrange taller plants on one side to avoid shading shorter plants.
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Plant quick-growing vegetables and lettuces on one end so you can harvest them sooner and replant.
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Water thoroughly after planting. The soil should be moist but not soaked.
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Consider adding supports as needed. Tomato cages for tomatoes, trellises for climbing plants, etc.
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Mulch around plants with compost or grass clippings to retain moisture. Leave space around plant stems.
I planted my tallest tomato plant on the far end, with peppers and herbs in the middle and lettuce on the front end. I surrounded plants with compost and added tomato cages.
Caring for Your Planter Box Garden
Consistent care and maintenance will keep your plants healthy and productive all season long. Here are some tips:
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Water when the top 1-2 inches of soil become dry. Water slowly and deeply.
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Fertilize every 2-4 weeks with an organic vegetable fertilizer following package directions.
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Prune and trim plants as needed to keep them tidy and productive.
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Weed weekly to avoid competition for nutrients and water.
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Check for pests and diseases. Treat organically at first sight.
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Harvest regularly as veggies and herbs mature. Frequent picking encourages more production.
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Remove spent plants and replace with new ones. You can often get multiple successions of crops like lettuce or radishes.
Caring for my planter box garden takes just 10-15 minutes a day. It’s a relaxing, rewarding way to grow food even with my limited space.
FAQ
How often should you water a planter box?
Water planter boxes whenever the top 1-2 inches of soil become dry. Water slowly and deeply, soaking the entire soil. Avoid frequent, light watering, which only moistens the surface.
What can you grow in a planter box?
You can grow herbs, leafy greens, vegetables, small fruits, and flowers in planter boxes. Focus on compact, dwarf or patio varieties. Tomatoes, peppers, beans, lettuce, kale and strawberries are great choices.
How deep should soil be in a planter box?
Aim for at least 12 inches of soil depth. Anything less than 10 inches will significantly limit plant options. Go as deep as you can – 18-24 inches is ideal for growing larger plants like tomatoes.
Should you put gravel at the bottom of planter boxes?
Adding a shallow layer of gravel, pebbles or stones at the bottom can improve drainage. Just don’t use more than an inch or the soil depth will be too shallow. Leaving space at the bottom is even better for drainage.
What size planter box do I need?
Size your planter box based on available space and what you want to grow. Small planters (2 feet) work for herbs and greens. Larger boxes (3-4 feet) allow growing tomatoes, peppers, beans and more.
Following this simple guide will help you plant and care for a thriving planter box garden, even if you’re short on gardening experience. With a properly prepared planter box and the right maintenance, you can grow plenty of fresh fruits, vegetables and herbs – no matter how limited your outdoor space.
Step 1: Fill your portable container with soil
For any container planting, you’re going to use potting soil. Don’t just grab soil from your yard—it’s too heavy, likely has a lot of clay or rock, and can contain bugs and disease spores. There are a few potting mixes out there specifically for veggies, but we find a regular, quality potting mix is just fine for an edible garden, especially if you also use a natural fertilizer. And don’t use compost alone to fill a container you’re planting in—some edible plants may like the soil that rich, but not all plants do.
Next, choose a fertilizer. At Swansons, we like a natural vegetable and herb fertilizer that you sprinkle on top of the soil, then mix in. You can also get a fertilizer specifically for acid-loving plants, if you’re planning to grow blueberries. We like both Dr. Earth and Espoma brands.
Follow the directions on the fertilizer bag for how much to use per cubic foot and mix it in as you’re planting. You’ll want to add fertilizer every three to six weeks throughout the season because nutrients run through a container more quickly than they do in the ground.
You should fill your containers as fully as possible, about ¼ – ½” from the top. The potting soil will settle as it’s watered, and the plant’s roots need as much space to grow as possible.
What are planter boxes made of?
While there are as many different materials as there are planter box sizes, a few choices are popular for a reason. The wood planter is a common, low-cost choice that is easy to DIY thanks to readily available materials. Long lasting options include cypress, redwood, and cedar.
Other materials commonly used in outdoor spaces include moulded concrete or aggregate, galvanized or coated metal, and combination wood-and-metal.