Creating a Trellis for Raised Bed

Skip Jute. Choose Mason's Twine.

Your trellis will only be as good as the string that holds it together. Skip twine, jute, or anything made of natural fibers. They'll quickly rot and will have to be replaced quickly. Mason's twine, 50-lbs test, and made of some sort of polypropylene works very well. The same twine strung last year and subjected to the heat of summer and the cold of winter has shown few signs of deterioration.

Place Eye Hooks at 6 to 9 Inch Intervals Across Top, Bottom, and Sides

This allows all sorts of flexibility when it comes to creating designs, be it diagonal, vertical, horizontal, or perhaps a trendy European basketweave or houndstooth. My first go 'round was at 12 inch intervals. This was a bit too far for the peas for their liking as it took some coaxing to get them to grab hold of the string.

Anchor Your Line with Two Half-Hitches
Say what? This should help. See picture.

String Your Line Through the Eye Hooks

Working side to side and then top to bottom, string the line through the hooks. Double up the line and make an extra pass on the lower levels. They'll be the first levels of support, so give yourself a bit of insurance. Line is cheap. Your time isn't.

Create a Cleat to Tie Off Your Line & Adjust Tension

Anyone who's spent time around a boat knows how to tie a cleat knot. (Video and instructions here.) This allows you to place tension on the lines as needed and quickly and securely tie off your line. To create the cleat, drive two nails about an inch apart into the wood -- one at an angle down and the other at an angle up. See the picture for details. Alternatively, they sell cleats in hardware stores that are meant to be used with blinds.

Tip: Peas Cling Most to Horizontal Supports, Pole Beans Cling to Vertical Supports
Consequently, provide more vertical support for beans and closer horizontal supports for peas.

Filling Raised Garden Bed with Dirt

An 8'x4'x1' bed holds (get ready for some serious math) 32 cubic feet of soil, laundry, or stray cats. That's enough dirt to seriously strain the shocks of an aging station wagon, but not quite enough to make it worth renting a truck and visiting the dirtmonger. Perched high atop the horns of a dilemma, the problem was resolved when a recent price war between Lowes and Home Depot ushered in sale prices on Miracle Grow Garden Soil, 2 cubic feet for about 6 and half dollars. At that price, it made sense to buy about 14 bags of soil and 200 pounds of composted cow manure, which, surprisingly, isn't exactly dirt cheap. Along with a hefty amount of sphagnum peat moss, it took 12 bags of soil and 160 pounds of composted cow manure to fill the bed within an inch of the top.

Positioned on the margin of a fairly wooded section of yard, the bed was lined with some landscape fabric. It's hoped this will keep weeds and roots from growing into the bed -- at least for a little while.

Raised Garden Bed Completed

Last weekend, the weather was finally nice enough to complete the raised garden bed. With a little input from "The Compost Bin," who advised that my structure didn't need extra bracing, the whole thing went together in about 45 minutes.

The final product deviated from the original plan slightly in that the trellis is positioned on the inside of the bed rather than the outside. All of the lumber came in 8 foot lengths. Securing the trellis to the outside of the frame would have required two sections of 2x4s, which would have been a pain. Unsure of just how visually appealing the trellis would be, it's been secured using galvanized lag bolts that can be unfastened.

All in all, she holds 32 cubic feet of dirt. Priced out by the bag, that'd be about $112 - $120. (Incidentally, there are 52, 40 pound bags of dirt in a cubic yard.) Luckily, there's a pretty swell dirt yard near me that sells a cubic yard of screened loam/compost mix for $30 picked up. Tack on a $20 U-Haul pickup rental, and that's not too shabby. Unfortunately, my desire to garden is not matched by my dirtmonger's ability to supply dirt. Given that it snowed just last weekend and a touch of snow in the in offing this week, much of the dirt is still frozen.

Source: http://www.therockpile.com/pages/order_soil.htm

Raised Bed Construction Plans

The thermometer suggests otherwise, but warmer temperatures are not too far off. It's time to get building. After a few weeks of research, here's a compilation of my raised bed gardening knowledge. In the thumbnails are plans for a 4' by 8' raised gardening bed I made using Google SketchUp. Unlike most designs I found, this one has a trellis for growing peas and training tomatoes. Although a trellis can be fashioned out of PVC, the wood should provide a more soothing appearance.

UPDATE: See the finished product here. See how to string a trellis here.

The Benefits of Raised Beds
Much has been written on the subject, such as here, here, and here. In short, raised garden beds give complete control over soil conditions. The soil is keep loose and well aerated because we're not walking all over it.

Wood: Natural or Pressure-Treated?
This structure will take a beating. It will be outside in the elements, freezing, thawing, roasting, and, it will almost always be wet. Under these conditions untreated lumber (except for naturally rot resistant species like cedar or black locust) will almost certainly rot in a short amount of time, perhaps a couple of years. Pressure-treated, however, easily might last a decade or more. Even though some authorities state that newer pressure-treatment agents such as ACQ are safe to use around kids and food, let's not forget that the old formulation, CCA, has been taken off the market out of fear that it was leaching arsenic into the environment. With all of this conflicting information, others simply play it safe and go with untreated wood.

The Materials
The Raised Bed Frame
(2) 8' 2x12s
(2) 4' 2x12s
(1) 4' 2x4
(4) 1' 4x4s

The Trellis
(2) 5' 2x4s
(1) 8' 3" 2x4
(2) 3' 1 7/16" 1x4s (bracing)