Field guide · Bed prep
30-Inch Bed Prep: Broadfork, Compost Rates, and a Stale Seedbed
A 30-inch bed is 30 inches of planted soil with 12–18 inch paths. Prep is the hour you spend so the next twelve weeks of hoeing stay short. Skip structure work and you fight a crust. Dump compost without a rate and you grow weeds and soft necks.
This sequence assumes drip irrigation, hand tools, and soil you can sink a broadfork into. If the ground is holding standing water, wait for it to drain.
Dimensions you actually work to
- Bed width: 30 inches planted.
- Path: 14–18 inches. Sixteen is a comfortable default for a wheel hoe.
- Bed length: whatever fits the block. Math below uses 50-foot beds because the numbers stay round: 125 square feet of bed surface each.
A quarter acre of beds at this spacing is roughly 50–60 beds of 50 feet, depending on headlands. Prep them in batches of ten so compost does not sit and sprout.
Broadfork first, not tiller first
On ground that was in cover or sod last season, broadfork 8–12 inches deep. Tines every 8–10 inches across the 30-inch face. Step, rock back, step. Do not invert the soil. You are opening pores, not making a furrow slice.
One 50-foot bed takes 12–20 minutes if the soil is at field capacity — dark, forms a ball, breaks with a thumb. If it ribbons into clay snakes, it is too wet. If it puffs as dust, water the day before and wait 12 hours.
Established beds that were not compacted by harvest totes only need a fork every second or third rotation, or after a heavy rain plus foot traffic. Forking every crop is wasted back.
Compost rates that match the crop
Finished compost, screened 1/2 inch or finer. Not raw manure. Not wood chips.
| CROP CLASS | COMPOST ON A 30 IN × 50 FT BED | PER 10 BED-FEET | NOTES |
|---|---|---|---|
| Heavy feeders (brassicas, fruiting solanums, sweet corn) | 80–100 lb | 16–20 lb | About 1/4 inch if the compost is 40 lb/cu ft |
| Moderate (lettuce, chard, onions, carrots) | 40–60 lb | 8–12 lb | Skip if the previous crop was heavily fed and residue remains |
| Light / legumes | 0–30 lb | 0–6 lb | Inoculate beans and peas instead of feeding them nitrogen |
A 5-gallon bucket of finished compost is 20–25 lb. A 50-foot heavy-feeder bed is four buckets. Spread across the 30 inches, rake 1 inch into the surface. Deeper burial of compost grows weeds from the seed bank you just uncovered.
If a soil test last season showed phosphorus above 80–100 ppm Bray, cut compost in half and use a low-P source. Compost is not a neutral mulch. It is a fertilizer with a weed seed tax.
The stale seedbed, on a clock
Stale seedbed means you water, let weed seeds germinate, kill that flush, then plant into a quieter surface.
- Broadfork and rake the bed smooth. Apply compost if the crop needs it.
- Irrigate to field capacity — drip until the top 2 inches are wet, usually 45–90 minutes on 12-inch emitter drip.
- Wait 7–10 days at soil temps above 60°F, 10–14 days if soil is 50–60°F.
- Kill the flush with a sharp 5–7 inch collinear hoe, flame weeder, or a very shallow rake. Do not dig. Cutting 1/4 inch below the surface is enough.
- Plant or transplant the same day or the next morning. Do not irrigate hard again until after the crop is in, or you start a second flush on top of the crop.
Two stale cycles before carrots or direct-sown onions is worth the extra week. One cycle is enough before transplanted lettuce.
A half-day plan for ten beds
- Hour 1–2: fork ten 50-foot beds.
- Hour 2–3: dump and rake compost on the six beds that need it.
- Hour 3: lay or reseat two lines of drip per bed, 12 inches apart, 4–6 inches in from each shoulder.
- Then leave them. Come back in 8–10 days with the hoe.
Do not plant the afternoon you forked a wet bed. Footprints that shine are compaction you just put back.
Paths are part of prep
Sixteen-inch paths packed by foot traffic become puddles. Once a season, scrape path soil back onto the bed shoulders and lay 2 inches of coarse chips or straw in the path. That keeps the 30-inch face from slumping 2 inches wider every month.
Do not dump compost in the path "for next year." You are fertilizing weeds at shin height.
Mark bed numbers with a stamped metal tag on a stake, not a Sharpie on drip tape. Tape gets replaced. The tag stays. When you write compost pounds in a notebook next to bed 14, you can stop guessing whether that brassica bed was already fed in March.
Key numbers
- Bed 30 in, path 14–18 in; a 50 ft bed is 125 sq ft.
- Broadfork 8–12 in deep, only when soil is at field capacity.
- Heavy feeders: 80–100 lb compost per 50 ft bed (four 5-gal buckets).
- Moderate: 40–60 lb. Light: 0–30 lb.
- Stale seedbed: irrigate, wait 7–14 days, shallow hoe, then plant.