Hugelkultur Bed Designer

Build a wood-core garden mound. Sizing, materials volume, wood selection, layering, and 5-year planting plan.

Design a hugel mound

Length (ft)

Base width (ft)

Height (ft) Traditional 6-7 ft; small hügel 2-3 ft

Style Trench-style (dug 1 ft below ground) Raised (built on grade) Terraced / contour

What hügelkultur is

A traditional Eastern European garden bed built on a wood-core foundation. Logs and branches buried under soil decompose slowly over 10-30 years, releasing nutrients, holding water, and creating a self-fertilizing mound.

Layer	Material	Function
Bottom (largest)	Hardwood logs (8-12" diameter)	Long-term water storage; slow decomposition
Mid-bottom	Smaller branches, twigs (1-4")	Faster decomposition; air channels
Mid-upper	Plant matter (leaves, straw, garden waste)	Quick decomp; initial nutrient pulse
Upper	Manure, compost, kitchen scraps	N-rich layer to balance C-rich wood
Top (4-8")	Topsoil + finished compost	Planting medium
Outer cover	Mulch, straw, or living groundcover	Hold soil, reduce evaporation

Wood selection

Best wood (use freely)	OK (some caveats)	Avoid
Aspen, alder Apple, pear, peach (well-aged) Birch Cottonwood, poplar Maple Oak (slow decomp; very long-lasting) Willow (uses water aggressively first year)	Pine, fir, spruce — OK but acidify soil Cherry — wilt-prone; use only well-aged Eucalyptus — allelopathic; age 1+ years first Cedar, juniper — slow decomp; long water-bank	Black walnut — juglone is toxic to many plants Black locust, black cherry, redwood — extreme rot resistance defeats the point Treated lumber (CCA, ACQ) — toxic chemicals Diseased wood (chestnut blight, oak wilt)

Planting through 5+ years

Year	What's happening	Plant for
Year 1	Wood absorbs N as it begins decomposing — N tie-up at top layer	N-fixing legumes (peas, beans, clover); heavy mulch; potatoes; squash; nasturtium
Year 2	Decomp accelerates; N starting to release	Tomato, pepper, eggplant; greens; brassicas
Year 3-5	Peak fertility; soil structure now excellent	Anything; this is when hügels shine
Year 5-15	Slow N release continues; mound shrinks ~25-50%	Continue intensive vegetables; perennials thrive
Year 15+	Mound mostly leveled; rich organic-soil mound	Plant with annuals or rebuild

Build process

1. Dig trench (if trench-style) ~12" deep, full bed footprint.
2. Soak the largest wood thoroughly — aged hardwood logs that have already absorbed water are ideal. Dry wood sucks moisture from soil for the first year.
3. Layer largest logs at bottom, packed close. Aim for ~50% of mound volume = wood.
4. Fill voids with smaller branches, then leaves and plant matter. Walk on it to compress.
5. Add manure / compost layer (3-6") to provide N for decomposition.
6. Cap with topsoil + compost mix (4-8" deep) where you'll plant.
7. Mulch heavily (4-6") and water thoroughly.
8. Plant N-fixers in year 1 — let the system establish before heavy feeders.

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