How to get the best results from planter boxes
With all these benefits, it’s easy to see why gardeners love planter boxes. Thankfully, growing successfully in boxes of various sizes and styles isn’t difficult. But it’s worth considering the following tips to get the most from your planters.
1. Use a soil mix designed for planters and containers.
While it might be tempting to fill your planters with garden soil, please don’t fall for that particular temptation. The soil that fills in-ground gardens is heavy and dense. That’s a poor combination for container growing.
Instead, choose a sterile mix designed for planters and containers. These mixes will usually include ingredients to aerate your soil and keep it light (such as shredded bark or coconut coir), materials to increase soil filtration and retention of nutrients (perlite, pumice or vermiculite), along with compost or other organics. They might even be soil-free.
2. Ensure your planter box has adequate drainage.
In addition to filling your planter with well-drained soil, be sure your planter box isn’t watertight. This can happen when converting basins or watering troughs into planters. The water needs to escape somewhere or your plants’ roots can get waterlogged.
Wood planters often have slots where the wood comes together. In these cases, water can usually escape. In other cases, extra drainage will be needed. Drainage holes should be about 9” apart and no smaller than ¾” in diameter.
3. Choose the right size box for your plants.
Garden planter boxes offer ease and versatility. Not only can you find L-shaped and U-shaped planters along with the standard rectangles, you can also find them in a variety of sizes. The question is, how big should you go?
Measuring your space is the easiest way to determine what length and width planter will best meet your needs. If your planter is two feet or narrower, you won’t need access on both sides to tend your bed, since you should have no trouble reaching across. Anything wider, and you’ll need access from both sides.
But what about depth? While most vegetables will grow well with under 24” of soil, some varieties need up to three feet. These are usually not the best choices for planter boxes. For more information, see
4. Locate your planter in the right place.
Like any garden bed, your planter will need enough sunlight for the plants you hope to grow. Most vegetables do best with 6-8 hours of full sunlight. Leafier crops like lettuces, arugula, kale, and Swiss chard, will tolerate slightly fewer hours or benefit from some dappled shade in the afternoon. To test the sunlight available in different spots on your patio or balcony, use a sunlight calculator or download one of the sunlight apps available through your cell phone.
Another thing to consider when locating your planter is proximity to water. If you aren’t installing irrigation, you’ll want to be close to your hose bib to avoid lugging water. This is equally true if you plan to use a soaker hose. Having your planter close to the kitchen can also be convenient when growing greens and herbs.
5. Choose suitable plants.
As noted above, there are some plants that don’t do well in planter boxes unless you have the soil depth required to help them thrive. The good news is that as more and more people turn to urban gardening, newer varieties of plant breeds designed for patio living have come onto the market. You can now find ‘patio’ or ‘compact’ varieties for most popular fruits and vegetables. Here are some of our favorites:
|Tomatoes: Tumbler, Tiny Tim, Red Robin, Manitoba||Peppers: Black Hungarian, Red Bulls Horn, Right on Red, Hungarian Hot Wax, Ancho|
|Squash: Shokichi Green Mini Kabocha, Raven or Bush Baby Zucchini||Cucumbers:Patio Snacker, Spacemaster, Tasty Green, Picolino|
|Sweet potatoes: Vineless Puerto Rico, Vardaman||Strawberries: Rose Berries Galore, Tribute, Fresca|
|Watermelon: Solitaire, Sugar Baby, Black Beauty Mini||Blueberries: Pink Icing, Peach Sorbet, Jelly Bean|
|Carrots: Little Fingers, Romeo, Paris Market||Raspberries: Raspberry Shortcake, Heritage|
You can also choose from the many vegetables that thrive in planter boxes less than 24” deep: