Elevated planters are a nice way to garden in a "non-traditional' way. The traditional way of gardening, if we want to call it that, involves the use of open soil areas or dedicated portions of our property that we use for something other than turf. Examples would include the flower border, vegetable garden, foundation plantings and other areas of specific use. These types of garden spaces frequently require maintenance that invites us to kneel, stoop, bend, crawl and otherwise contort to keep up with planting, weeding, picking produce, etc. at ground level. Another potential drawback to this system is that we are reliant on our current soil structures although those can be modified by amendments, mulches, synthetic materials and even removal/replacement. In many cases, poorer soils that we inherit with our properties are a daunting challenge that may deflate our original hopes of growing vegetables, or acid loving plants and/or plants that just wont thrive because of those initial soil limitations.
Elevated planters allow us to "bring the garden up" to a comfortable level that allows us to minimize or even totally avoid the need to kneel, stoop, bend, crawl and contort. By elevating the growing situation (soil and plants), we're better able to continue gardening when some of the challenges with the traditional garden limit our ability and interest. Elevated planters are not just for older gardeners or those with some physical challenges, they are for any of us that want a little more convenience and accessibility as well. We provide the soils for these built planters, thereby creating an ideal situation for our "plants of interest". Consider a garden that has little or no traditional growing space that only provides the homeowner with a small deck or patio. Condos and assisted living apartments may have strict limits to gardening on the property and it may be limited to these patios and decks. Containers are a great option and an elevated planter, which is just a large container when you think of it, can also provide some significant growing opportunity and gardening potential. Remember that this mini-garden and its living contents are expecting decent soil, adequate watering, appropriate sunlight and other inputs as do all your landscape plants.
This short blog can't address the myriad designs that are out there for elevated planters but I've included some photos of those that I've observed. I'm no carpenter but I do want to stress that these planters need to be of solid construction as they will be supporting quite a bit of weight with the combination of wet soil and increasingly larger plants. There are also debates on whether treated lumber is appropriate for these or not. Look in to the research on this as there are some valid concerns. The soil preparation for these containers can be quite variable but will be determined by what you want to grow. We replace our soils each year in these and compost the soil from the previous year. Many of these planters are designed with clearance for wheelchair accessability in mind and are perfect height for an average height man or woman to comfortably garden. The best elevated planters I've seen in terms of plant "happiness" are those that are at least 9" - 12" deep. The more shallow planters tend to dry out quickly and don't provide adequate rooting volume for many of our plants including most of the vegetables. Do look in to this topic further. At RBG, we've built about 8 different styles of raised planters (including the accessible planting desk with inserts directly below) and will continue to observe their effective uses.