Planter Boxes: 5 Tips for Selecting the Best One

Tip #1: Your Planter Box Depth Determines What Plants You Choose

Planter Boxes come in various sizes. So, your first step is choosing one that will fit your space. Its size will also determine what types of vegetables you can grow.

Your main concern is the container’s depth. The larger your planting box, the more plants you can grow. However, the depth of your gardening container determines what you can grow.

A plant’s roots need room. If restricted, it stunts plant growth. Roots need sufficient space for nutrient uptake and photosynthesis. So a deeper planter box provides more real estate for roots to flourish.

Your gardening container’s depth also impacts soil moisture. Deeper planter boxes require less watering due to their added soil volume. There's another advantage to containers with more soil between the side and bottom. It helps protect plant roots from temperature extremes.

Appropriate Gardening Box Depths for Various Plants

A 6- to 8-inch-deep planting box for most plants will do the trick. That depth easily allows you to grow radishes, onions, lettuce, garlic, spinach, chives, and virtually any herb.

For example, EarthBox Junior gardening boxes are 7-1/4” deep, making them perfect for any vegetables mentioned.

Step up to a planting box 10 to 12 inches deep, and you can grow deeper rooting vegetables and herbs. So, now you’re talking about carrots, tomatoes, beans, peppers, beets, parsley, and rosemary.

EarthBox Original boxes for gardening are 11 inches deep, plenty for deeper rooting plants. Root vegetables like potatoes, carrots, beets, sweet potatoes, or turnips need even more depth. An EarthBox Root & Veg box for planting vegetables is 15 inches deep. It’s specifically designed for root vegetables.

Tip #2: Planter Box Materials Make an Impact

Planter boxes are made from various materials, including wood, plastic, metal, and fabric. Each material has its pros and cons.

Wood Planter Boxes

Wood is a natural material that looks great but can be susceptible to rot and decay. So you have to be careful selecting the wood type. Cedar and redwood are your best options. Both are durable and rot-resistant.

Pine and fir work equally well but lack the water resistance of cedar and redwood. So you’re planting boxes won’t hold up nearly as long.

Treated lumber offers longevity. However, there’s an argument about whether the chemicals used to treat the wood hurt your plants.

Metal Planters

Metal is solid and long-lasting but can be expensive. Galvanized metal, in particular, withstands the elements and can hold the weight of the gardening container’s soil.

You might choose a metal planter box if you have a more modern garden. Generally, they’re made from copper, zinc, or steel and add a unique flair to your garden.

Although metal planting boxes reflect the sun, they still get pretty hot. As a result, you risk burning your plants. Plus, the container’s soil can dry out quickly. So you’ll need to pay close attention to watering.

Fabric Planters

Also known as grow bags, fabric planters are porous. That allows for better drainage and aeration of soil for healthier roots while preventing root rot. They’re also lightweight and easy to move.

Grow bags are inexpensive if cost is a significant consideration. However, they aren’t durable. So you can expect to replace them every two or three growing seasons.

Owing to their porous nature, fabric planters will dry out quickly. And that translates to watering more often. Additionally, if you’re growing plants that like moist soil, you’ll want to consider another container type. For example, asparagus, celery, watercress, and arugula fall into that category.

Plastic Planter Boxes

Plastic is a popular choice for planter boxes. They’re relatively inexpensive and durable. Like growing bags, they’re lightweight and easy to move. So, getting your plants out of the sweltering sun on an August day is easy.

Plastic gardening boxes retain water better than wood, fabric planters, or terra cotta.

Some plastic planting boxes are also self-watering. And that eliminates concerns about over or underwatering plants.

For example, sub-irrigated planters (SIP) use a fill tube. It lets you add water to a reservoir. As a result, plant roots can access water when needed.

That means less time spent worrying about whether plants need water or not. And more time spent watching your plants grow. EarthBox planter boxes include sub-irrigation.

Like metal, plastic can heat, specifically black planter boxes. So choose a lighter-colored plastic like terracotta. Plastic also doesn’t offer as much insulation for plants as wood.

Tip #3: Make Sure Your Planter Box Has Good Drainage

One of the caveats to box gardening is drainage. Planter boxes need drainage holes to prevent the roots of your plants from rotting. Ensure the planter box has at least a few drainage holes.

You won’t be concerned with a grow bag as they provide superior drainage. Most plastic gardening containers include drainage holes. They may even come with drainage plugs. So if you want to use the planter indoors, you can without worrying about moisture on a windowsill or table.

You’ll want to pay particular attention to wood and metal containers. In many cases, they lack appropriate drainage. Depending on the wood planting box, slots may open where the wood comes together to support drainage. If not, you’ll need to drill a hole into them to allow water to escape.

Tip #4: How Long Do You Anticipate Using a Planter Box?

Before you buy a planter box, ask yourself how long you plan to use it. Don't go overboard with your container if you’re getting your feet wet with box gardening.

You can limit your investment with grow bags, terra cotta, untreated wood, and low-grade plastic gardening boxes. The downside is that you’ll lose out on durability and longevity. You can expect two or three seasons from each, especially if left outdoors over the winter.

Invest in a more durable, longer-lasting container if you're a more serious gardener. Although generally expensive, metal gardening containers can last decades with proper care. It’s common for them to last up to 40 years.

Cedar or redwood planting boxes last a long time. A redwood gardening box, for instance, can last up to 30 years before rotting.

Although cheap plastic containers might last a few years (1-5), well-constructed plastic planting boxes can last up to 50 years. Moreover, they’re less costly than cedar, redwood, and metal.

Extending the Life of Gardening Boxes

You can extend the life of any gardening box by:

• Lining plant pots to prevent pests, moisture, and diseases from reaching them (especially wood)
• Painting the container to prevent rot or rust
• Cleaning the box before each growing season
• Moving your gardening boxes indoors over the winter
• Selecting a thicker material, particularly for wooden planters
• Ensuring they have proper drainage

Although the material significantly impacts longevity, these measures can improve the durability of the planter box. That's especially the case with outdoor planters.

Tip #5: Choosing a Planter Box That's Raised

When you water your plants, the draining water remains in contact with the bottom of the planter. That’s true whether you use the planter on grass or a patio.

So make sure you’re planter box effectively creates a raised bed. Look for a wood gardening box with legs to get it off the ground. At the very least, place the container on bricks or concrete blocks. A couple of inches works fine.

Many plastic planting boxes are available with casters or stands. For instance, EarthBox containers include an optional caster kit that raises the planter while making transport easier.

You can also purchase a garden stand. It keeps the planter box off the ground. It also makes accessing the planting more handy. So you won’t break your back harvesting or caring for your plants.

EarthBox: Box Gardening Made Easy

EarthBox® is a top-rated, trusted provider of planter boxes, gardening systems, and accessories. Its gardening boxes are lab-tested, so you'll be on the road to success growing vegetables, fruits, and herbs.

Take advantage of the company’s top-rated planter box kit to simplify things. You get everything you need for successful container gardening–just add soil and your plants.