Growing & Harvest · 8 min read
Raised beds: soil mix, depth and irrigation that actually works
Raised beds warm earlier and drain better, but only if they are filled and watered right. Build them once and harvest for years.
By WORKING ACRE Field Desk · Updated
Key takeaways
- Beds 10-12 in. deep suit most vegetables; 18 in. for root crops.
- Keep beds 4 ft wide so you never step in the soil.
- Drip lines on a timer use a fraction of the water of a sprinkler.
/ Size and layout
- 4 ft wide so you can reach the center from both sides.
- Paths at least 2 ft wide, 3 ft for a wheelbarrow.
- Run long sides north-south for even sun.
/ Soil mix
| Part | Share | Why |
|---|---|---|
| Screened topsoil | About 50-60% | Structure and minerals |
| Compost | 30-40% | Nutrients and biology |
| Aeration (pine bark fines, perlite) | 10% | Drainage |
/ Irrigation
- 01Header lineRun a 1/2 in. line along the end of each bed.
- 02Drip linesLay 1/4 in. drip lines or soaker tube every 12 in. across the bed.
- 03Pressure and filterAdd a pressure regulator and filter at the tap.
- 04TimerWater early morning, deeply and less often.
/ Season extension
Hoops and row cover can add several weeks on each end of the season. Clear plastic turns a bed into a mini greenhouse; remember to vent on sunny days.
/ Growing season checklist
| Season | Tasks |
|---|---|
| Late winter | Order seed, start seedlings indoors, service irrigation |
| Spring | Top up compost, set drip lines, harden off seedlings |
| Summer | Mulch, check timers, harvest often |
| Fall | Plant cover crops, drain lines before frost |
/ Frequently asked
Should raised beds have a bottom?+
Generally no, so roots can go deeper. Add hardware cloth underneath if gophers or moles are a problem.
Is treated lumber safe?+
Modern treated lumber is widely used; many growers prefer cedar, steel or a liner for peace of mind.