The plan at a glance
This is University of Maryland Extension’s salad table, developed in 2009: a frame of 2 × 4s on edge, 58 inches long and 33 inches wide, divided into three sections and floored with window screen under hardware cloth, so the water drains and the mix stays put. It stands on four legs, each two 2 × 4s screwed together, and the whole table comes from three 10-ft 2 × 4s and one 12-ft one. It holds 3 inches of mix for salad greens and herbs, at waist level, UMD says, where you can garden without kneeling.
Built to the cut list, the top of the frame is 33 inches off the ground, level with the tops of the long leg pieces, and the table is 36 inches across the outside of its legs. UMD gives the finished table as 36 inches tall to the top of the frame, so if the height matters, measure a leg against yourself before you cut.
Lumber, mesh and screws
UMD builds it from untreated framing lumber, each board cut as below with little left over. Nothing else is needed but the mesh, the fasteners and the latex paint or acrylic stain UMD coats it with.
| Part | Size | Where it goes | Pieces |
|---|---|---|---|
| Long sides | 2 × 4, cut to 58 in, both from one 10-ft board (4 in left over) | the two long sides of the frame | 2 |
| Crosspieces | 2 × 4, cut to 30 in, all four from one 10-ft board | the two ends and the two dividers | 4 |
| Inner leg pieces | 2 × 4, cut to 29½ in, from one 10-ft board (2 in left over) | under the frame, carrying it | 4 |
| Outer leg pieces | 2 × 4, cut to 33 in, from the 12-ft board (12 in left over) | outside the long sides, screwed to the frame | 4 |
| Window screen | aluminum, 3 × 5 ft | stretched across the bottom | 1 roll |
| Hardware cloth | galvanized, ½-in mesh, 3 × 5 ft (¼-in mesh costs more but is easier to work, UMD says) | over the screen | 1 roll |
| Deck screws | galvanized, 2½ in | the frame’s joints, the leg pairs, and three through each leg into the frame | 1 box |
| Staples and nails | ⅜-in staples and 1-in roofing nails | holding the screen and hardware cloth | 1 lb of nails |
Four 30-inch crosspieces use all 120 inches of a 10-ft board, so the saw cuts come off the last one: at ⅛ inch a cut it is about 29⅝ inches. Make it one of the two dividers, which sit inside the frame, so the ends keep the table square.
Build it
- Cut the four boards as the table above lists and smooth the cut ends with the rasp.
- Screw the two 58-inch long sides to the two end crosspieces, two screws into each crosspiece, drilling a ⅛-inch pilot hole for every screw. Check the corners with the square.
- Fit the two dividers between the long sides with their centres 19 9/16 inches from each end. That leaves three sections, each 30 by 17 5/16 inches.
- Turn the frame over. Center the window screen on the bottom and, with two people stretching it taut, staple it to the bottom and sides of the frame.
- Lay the hardware cloth over the screen, pull it taut and staple it to the bottom, then nail roofing nails along its edges. Snip diagonally in from each corner so the spare folds up onto the ends, not the long sides, where the legs go.
- Screw each 29½-inch leg piece to a 33-inch piece, their bottom ends flush, to make four legs. The flush end stands on the ground, or takes a caster.
- Set the frame on the short inner pieces, a leg 8 inches in from each corner along the long sides, and drive three 2½-inch screws through the top of each long piece into the frame.
- Coat the wood with latex paint or an acrylic stain against decay: painted or stained, spruce, pine or fir lasts about 8 to 12 years, UMD says, against 4 to 8 left bare. Then set the table level where it will stand and fill it.
What to fill it with, and how much
UMD fills the table with half soilless potting mix and half compost, or with soilless mix alone. It says to keep out garden soil, which is dense and carries weed seeds, and animal manures. Soilless mixes are peat moss, vermiculite and perlite, or newer blends of coir and rice hulls; work water into one before you mix in the compost, because dry peat moss repels water.
The table holds about 2.8 cubic feet (22 gallons) of mix, 3 inches deep, UMD says: two bags of 1.5 cubic feet, one of potting mix and one of compost for the half-and-half mix. Measured inside, the three sections come to 10.8 square feet, a little under UMD’s 11.1, so the soil calculator gives 2.7 cubic feet for them: still two bags.
Watered, 2.8 cubic feet of potting mix weighs about 110 to 240 lb, all of it on the mesh and the four legs. Check that against a deck or balcony before the table goes there (the hard-surface guide explains how). To move it with the seasons, as UMD suggests, fit sturdy casters to the flush ends of the legs before you fill it.
The mix breaks down as it weathers and holds less air, so at the end of each year UMD either takes it out and spreads it around other garden plants, or keeps half and mixes it with fresh: half the table is 1.4 cubic feet, one bag. Between two sowings in the same year, just top it up to almost level with the frame.
For peppers and tomatoes: a deeper frame
UMD suggests 2 × 6 sides for larger salad greens and bush beans, and 2 × 8 or 2 × 10 sides for peppers, determinate tomatoes and bush cucumbers. The frame’s lengths stay the same; on the same legs, its top rises with the wider board. Filled half an inch under the top, the three sections take:
| Sides | Grows (UMD) | Mix | Bags of 1.5 ft³ | Watered weight | Top of the frame |
|---|---|---|---|---|---|
| 2 × 6 | larger salad greens, bush beans | 4.5 ft³ | 4 | about 180 to 380 lb | 35 in |
| 2 × 8 | peppers, determinate tomatoes, bush cucumbers | 6.1 ft³ | 5 | about 240 to 510 lb | 36¾ in |
| 2 × 10 | peppers, determinate tomatoes, bush cucumbers | 7.9 ft³ | 6 | about 320 to 670 lb | 38¾ in |
Watered weights are for potting mix, from the ranges NC State and USDA researchers give.
The deeper the frame, the more the mesh carries. UMD’s answer is three 1 × 4 boards, each 58 inches long, fixed across the bottom to keep the hardware cloth from sagging, and its rule for any size is that the table works only as long as the weight of the moist mix and the plants can be supported.
What to grow in it
UMD has good results with every kind of lettuce, endive, arugula and its relatives such as kale, mustard greens and mizuna, with spinach, Swiss chard, parsley, cilantro and basil. Sow in rows about 4 inches apart, four rows 30 inches long or seven 17 inches long in each section, and thin the seedlings to 1 to 2 inches apart (basil 4 to 6, beans 3 to 4). Lettuce, arugula and other greens can be cut twice before you sow again. Once the seedlings are up, water every day with a watering can or a water breaker on the hose: about a gallon a day for the whole table, UMD says.
In Maryland, UMD keeps the table in 4 to 8 hours of direct sun until mid-June, moves it to shade (0 to 3 hours) until mid-September, then back into the sun; herbs such as basil, thyme and cilantro want at least 6 hours all season. For a deeper planter on legs, what to plant in a raised bed with legs goes crop by crop.
What this plan does not cover
This is UMD’s design as UMD publishes it, with the soil, weight and deeper-frame figures worked out here from its cut list. It is not an engineered design and makes no load rating, and the legs have no cross braces: UMD lists braces among the ways gardeners make the table sturdier. For a bed you can reach from a wheelchair, the accessible raised beds guide gives the heights and knee room; for a planter on legs ready-made, see the elevated planters.
Try it with your numbers
Open the raised bed soil calculator with this guide’s bed filled in, then change any figure to match yours.
Open the raised bed soil calculatorReferences
- Building Salad Tables and Salad Boxes, University of Maryland Extension.
- Choose a Site and Growing Media or Soil for a Salad Table or Salad Box, University of Maryland Extension.
- Growing Vegetables in Salad Tables or Salad Boxes, University of Maryland Extension.
- Plant, Fertilize, Water a Salad Table or Salad Box, University of Maryland Extension.
- Salad Greens to Grow in Salad Tables or Salad Boxes, University of Maryland Extension.
- Healthy Substrates Need Physicals Too! (HortTechnology 15(4), 2005), USDA Agricultural Research Service and NC State University.