Trex

Use Trex® to build low maintenance raised garden beds

Part one: Trex® and the raised garden bed

Raised bed gardening has become popular, and rightly so. By building elevated garden beds you can avoid dealing with imperfect local soil, help protect your plants from invading pests (and even your over-enthusiastic pets), and allow you to concentrate water and plant food where it is most needed. Raised beds are helpful for the handicapped and, because they relieve much of the bending and stress of ground-level gardening, can keep the rest of us from injuring ourselves, too

One problem with building raised garden beds can be the toll that outdoor weather can take on the container materials. Wood can rot or be invaded by termites. Cedar and redwood are the two most commonly resistant woods, but they eventually break down too, and still need regular applications of oil, paint or waterproofing. Treated wood like railroad ties and possibly ‘green wood’ can potentially leach chemicals into the soil so should be used with caution, especially around edibles. Vinyl can be a good solution but may be too flimsy for most uses unless it has a hard core added. Stone is another good choice, but needs to be lined or sealed so water and soil don’t filter out. Cement blocks can work well, but they can harbor pests in the holes, add lime to the soil and may not look very attractive. One more alternative as a building material is to use Trex®

Trex® is not the least expensive of materials since it is fabricated and requires more money to produce than something that is simply ‘harvested’. But it is made from recycled wood and plastic that would otherwise be filling up our landfills. It also is highly durable so the initial expense will be recouped in the first few years by savings in labor, repair, preservation treatments and overall maintenance.

One historical note about the company which carries the name of its product, Trex, is that it was formed as a division of the oil giant, Mobil Corporation. Organic chemist Roger Wittenberg independently discovered that compressing shredded waste plastic with sawdust could produce a superior building material. Mobil, being the country’s biggest producer of disposable plastic products was attracted to Wittenberg’s concept and worked up the timber application which was called Timbrex, later shortened to Trex®.

Using Trex® is Eco-friendly saving non-renewable or slow-growing resources and helping to reclaim waste. For the homeowner, using it will require little maintenance since it doesn’t need to be painted – ever – and will not split, warp or rot. On the downside, it is more costly than wood, but will make up the difference over time with its lack of care. It is also heavier than wood, and it is not structural. It was formulated for walking surfaces, railings and trim rather than for supporting beams. This means that if lengths are too long on the sides of your raised garden bed and lack enough supporting posts, they may curve or bulge slightly.

Use Trex® for a long-lasting, easy care material that is safe for using in vegetable gardens and for use with children and even mouthy pets. Unlike other materials that will require painting, washing, replacement and other maintenance, once your garden is built you can focus on growing your plants rather than caring for the container.

Check out the second part of this article, Part Two: How to build a Trex® raised garden bed, for directions on constructing the elevated garden.

How to build a Trex® raised garden bed: Part Two

There are many ways to put materials together to design and build a raised bed. Here are some guidelines for putting together a very solid, long-lasting elevated garden area using Trex®. Using recycled products for building along with growing your own food, herbs and cut flowers can all help you develop a productive, beautiful and sustainable landscape.

 

 

 

 

 

  • Measure out the space where you want to build your bed(s). Having multiple raised gardens will allow you to rotate crops or to diversify whatever you choose to grow.
  • If you want to irrigate your bed(s) set up PVC irrigation pipe to bring water to the inside surface of your container at the finished soil height when it will be filled.
  • Set in your posts. In this case we are using hollow vinyl posts used for fencing. The squared shape will make connecting boards easy and the vinyl can be easily cut, drilled and filled to give it weight. To keep your posts stable, dig deep holes, at least 12” deep, and set them with concrete footings.

  • Cut your Trex® boards to size with a saw. It cuts as easily as regular wood.
  • Predrill holes for lag bolts through the posts so you can easily mount the boards. You may prefer to temporarily mount the boards with single screws (one board layer at a time) and then drill your holes and bolt them in place.

  • Build your height one set of Trex® boards at a time. (Other materials like vinyl and wood can be used for this same design.)
  • If you have a problem with burrowing pests like gophers or moles, line the bottom of your garden bed with screening like ½” metal lath (or hardware cloth). This should keep critters from entering from below.

  • Once you reach the height you want, cut the fencing posts off so they are no higher than the sides of your garden bed.

  • Fill the hollow posts with concrete to make them strong.
  • Top the filled vinyl fencing posts with post caps. You can uses simple covers or get creative.  You can use solar lit caps or wire up low voltage lighted caps. There are a number of designs to choose from and you might even want to adapt a fence cap to hold poles for attaching netting or roofing over your raised garden bed.
  • Fill you raised bed with a mixture of rich soil that will best support whatever you plan to grow.
  • Set up a drip system or other type of irrigation system to efficiently water your bed. If you have multiple beds you may want to include individual water shut-off options for more control.

Note that if you are using Trex® boards horizontally, lengths over four feet — if the board is not thick enough — can bow slightly unless you bolt them to stabilizing uprights. Other than that, the material should endure for decades. It comes in an assortment of natural tones some of which may fade slightly over the first few weeks but then should maintain color intensity for many years to come.

 


Amazon Carousel Widget

Search Our Site

Feel free to search for articles on gardening, plants, news, landscape design, sustainable and eco-friendly products and tips, construction ideas, horticulture, garden events and more.

Garden/Landscape Articles