Raised Bed Soil Calculator
Raised Bed Soil Calculator
Calculate the exact amount of soil needed to fill your raised garden beds. This professional soil calculator estimates cubic yards, bags, and costs for optimal garden soil mixtures.
Raised Bed Depth Guidelines:
- 6-8 inches: lettuce, herbs, shallow root vegetables
- 10-12 inches: most vegetables, flowers, standard gardens
- 18-24 inches: tomatoes, peppers, deep root vegetables
- 24+ inches: fruit trees, perennials, permanent plantings
Soil Mix Recommendations:
- Basic vegetable mix: 1/3 compost, 1/3 peat moss, 1/3 vermiculite
- Square foot gardening: Mel's Mix (1/3 each compost, peat, vermiculite)
- Budget mix: 50% topsoil, 30% compost, 20% sand/perlite
- Premium mix: 40% compost, 30% aged manure, 30% coconut coir
Soil Components & Functions:
- Compost: nutrients, organic matter, soil structure
- Topsoil: bulk foundation, mineral content
- Peat moss/Coir: water retention, acidic pH balance
- Vermiculite/Perlite: drainage, aeration, lightweight
- Sand: drainage improvement, prevents compaction
Soil Costs (per cubic yard):
- Basic topsoil: $25-40 per cubic yard
- Garden soil mix: $35-55 per cubic yard
- Premium raised bed mix: $45-75 per cubic yard
- Organic compost: $40-60 per cubic yard
- Bagged soil: $80-120 per cubic yard equivalent
Raised Bed Construction:
- Materials: cedar, composite, galvanized steel
- Liner: landscape fabric on bottom (optional)
- Drainage: ensure drainage holes or raised bottom
- Location: 6-8 hours of sunlight daily
Soil Settlement & Maintenance:
- Initial settlement: soil settles 10-20% in first year
- Annual top-up: add 1-2 inches of compost yearly
- Soil testing: test pH and nutrients every 2-3 years
- Crop rotation: prevents soil depletion
Frequently Asked Questions
How much soil do I need for a 4x8 raised bed?
For a 4×8 ft bed at 12" deep: 32 cubic feet or 1.2 cubic yards. This equals about 16-20 bags of 2 cubic foot bagged soil.
How deep should my raised bed be?
12 inches minimum for most vegetables, 18-24 inches for tomatoes and root vegetables. Deeper beds hold more moisture and nutrients.
What's the best soil mix for raised beds?
1/3 compost, 1/3 peat moss or coconut coir, 1/3 vermiculite. This provides drainage, nutrition, and water retention.
Is bulk soil cheaper than bagged soil?
Yes, bulk soil costs 50-70% less than bagged soil. Bulk is economical for beds requiring 3+ cubic yards.
How often do I need to replace raised bed soil?
Don't replace - just add 1-2 inches of compost annually. Good raised bed soil improves over time with proper maintenance.
Should I use a liner in my raised bed?
Optional landscape fabric can prevent weeds from below, but ensure it's permeable for drainage. Avoid plastic sheeting.