Skip to content
SUS Farms — Allegedly Organic
← Back to Utah GardeningDownload PDF

beds · beginner · 5-min read

Raised beds for high-desert gardens

Raised beds aren't about looking nice — they're a workaround for native soil that drains poorly, cooks tender roots, or holds salts. In Utah they're especially useful because we can replace the alkaline native dirt with a controlled mix and amend without trying to fix five acres at once.

The 60-second version

Key takeaways

  • 01.Maximum 48" wide so you can reach without stepping in
  • 02.12" deep is enough for most vegetables
  • 03.50/30/10/10 mix: topsoil, compost, sand, peat
  • 04.Untreated cedar or block — never pressure-treated

Section 1

The 48-inch rule

A raised bed should be at most 48 inches wide. That's arm-reach from each side without stepping in. Step in once and you've compacted the soil — every step undoes a season of root development.

Section 2

Soil mix

Our recipe: 50% topsoil (screened), 30% finished compost, 10% coarse sand or perlite, 10% peat or coir. The peat lowers pH and improves moisture retention; the sand prevents compaction. A 4×8 bed at 12" deep needs about 32 cubic feet of mix — call it 1.2 cubic yards.

Section 3

Edging — what to avoid

Pressure-treated lumber leaches preservatives into food beds. Railroad ties are creosote. The right answer is untreated cedar, redwood, or concrete block. Cedar 2x10s last 8–12 years untreated. Block is forever.

Section 4

Drip line at surface, mulch on top

Drip line laid on the soil surface, 2 inches of straw or wood-chip mulch over it. The mulch shades the line, holds moisture, and suppresses weeds. Run drip 30 minutes 3× a week in summer.

Tools & materials

What you’ll actually need

The shopping list. Everything below earns its place — we wouldn’t list a tool we don’t actually use on the farm.

Untreated cedar 2x10 lumber

Builds 12"-deep raised bed walls that last 8-12 years. Avoid pressure-treated and railroad ties — both leach into food crops.

Concrete blocks or stone

Permanent alternative to wood. Cells in concrete blocks can be planted with herbs.

Hardware cloth (1/2" mesh)

Line bed bottoms to keep gophers out. Bend edges 6" up the inside walls.

Topsoil + compost + sand + peat (50/30/10/10 mix)

The standard high-desert raised-bed mix.

Drip line + landscape staples

Surface-laid drip pinned with staples. Two parallel runs cover a 4-foot bed.

Things we’ve done wrong

Common mistakes & how to avoid them

Each of these has cost us a season at some point. Easier to learn from someone else’s mess than your own.

1.

Filling with potting soil

The fix:Potting soil is mostly peat — dries out daily, costs a fortune to fill a bed. Use the 50/30/10/10 mix (topsoil/compost/sand/peat) instead.

2.

Building too wide

The fix:A bed wider than 48" forces you to step inside to reach the middle. Step in once and you've compacted soil for the season.

3.

Using pressure-treated lumber

The fix:Modern PT uses copper compounds that leach into food beds. Untreated cedar lasts 8-12 years and won't poison your tomatoes.

Common questions

Frequently asked

+How does Utah's climate affect raised beds for high?

Utah is high, dry, alkaline, and seasonally extreme. Compared to the humid east-coast advice in most gardening books, we deal with shorter shoulder seasons, more intense summer sun and UV, lower humidity (faster water loss), and soils that lock up iron and zinc. Adjust east-coast guidance accordingly: more water-conscious, more shade in summer, more attention to soil pH.

+Where do I find Utah-specific research?

USU Extension (extension.usu.edu/yardandgarden/) maintains the deepest archive of Utah-specific plant research in the state. Their Master Gardener helpline answers homeowner questions free. The Utah Climate Center at climate.usu.edu publishes 30-year climate normals for nearly every weather station — useful for planning frost dates and water budgets.

+How long until I see results?

Depends on what you're measuring. Soil amendments take 1 full season to show effects (sulfur for pH takes 4-8 months). Pest exclusion shows immediately. New plantings need 2-3 seasons to establish before drought tolerance kicks in. The biggest win is consistency — small actions taken weekly outperform big once-a-year efforts.

+Why not just plant in the ground?

You can, and many growers do. Raised beds win when native soil drains poorly, holds salts, or is so alkaline that amending in-place is impractical. They also raise the working height for older gardeners. The tradeoff is upfront cost and the need to refill soil periodically.

+Can I do this on a small backyard, or do I need acreage?

Almost everything in this guide scales down. A 4×8 raised bed, a few containers on a deck, or even a single fruit tree in a side yard each benefit from the same principles as a working farm — they just operate at different volumes. Container gardening is its own art and is well-suited to renters and small spaces.

Sources:USU Extension — Raised Beds·SUS Farms field notes, Sevier County

Keep going

Related guides

Container gardening when ground is bad

Pot size, soil mix, drainage, watering. The minimum container math for tomatoes, peppers, and herbs.

Read →

Backyard greenhouse — sizing and orientation

8×10 vs 10×12, polycarbonate vs glass, vent fans, heat mats. The setup that actually pays back.

Read →

Utah's alkaline soil — and what to do about it

The pH map of Utah looks like a wall of red. Here's how to work with it instead of against it.

Read →