I'll admit something that might surprise you - those herbs growing on your windowsill aren't actually free. Sure, you're not cutting checks to suppliers, but you've invested real money in containers, soil, seeds, plus countless hours tending them. Your margins depend on calculating these hidden costs accurately.
Why self-grown ingredients aren't free
Plenty of restaurant owners assume their homegrown herbs or vegetables cost nothing. Wrong. You've made upfront investments and you're spending valuable time on maintenance every single week.
⚠️ Watch out:
Skip factoring in self-grown ingredients and your margin looks artificially high. This creates a false picture of your actual profitability.
Calculate your costs per kilo or per plant
Getting an accurate cost price means gathering every expense and dividing by your total harvest.
💡 Example: Growing basil
Annual costs for 20 basil plants:
- Containers (20x €3): €60
- Potting soil per year: €25
- Seeds/seedlings: €15
- Water (estimated): €20
- Time (2 hours/week × 52 × €15/hour): €1,560
Total per year: €1,680
Harvest: 10 kg basil per year
Cost price: €1,680 / 10 kg = €168/kg
Time becomes your biggest expense
Most entrepreneurs completely forget to factor their own time. Spending 2 hours weekly on containers? Calculate your hourly rate properly.
- Conservative: €15/hour (minimum wage)
- Realistic: €25/hour (entrepreneur earnings)
- Full: €40/hour (opportunity costs)
💡 Example: Growing tomatoes
Setup for 15 tomato pots on terrace:
- Containers: €90 (depreciation 3 years = €30/year)
- Soil, fertilizer, seedlings: €45/year
- Water: €30/year
- Time: 3 hours/week × 6 months × €20/hour = €360/year
Total costs: €465/year
Harvest: 25 kg tomatoes
Cost price: €465 / 25 kg = €18.60/kg
Compare with supplier purchase price
Now you can honestly evaluate whether growing your own makes financial sense. Check what you're paying your vegetable supplier for identical quality.
⚠️ Watch out:
Compare like with like. Organic basil from suppliers might cost €40/kg, but standard basil runs €15/kg. What quality are you actually growing?
Apply the cost price to your recipes
Use your calculated cost per kilo in recipe cards, exactly like purchased ingredients. Based on real restaurant P&L data, operators who track homegrown costs discover their food costs are typically 3-5% higher than assumed.
💡 Example: Margherita pizza
Ingredients per pizza:
- Dough: €0.65
- Tomato sauce (own tomatoes, 50g): €0.93
- Mozzarella: €1.20
- Basil (own, 5g): €0.84
- Olive oil: €0.15
Cost price per pizza: €3.77
Selling price €14.50 incl. VAT = €13.30 excl. VAT
Food cost: 28.4%
Factor in seasons and risks
Growing your own carries risks that suppliers don't:
- Failed harvest: Disease or bad weather strikes
- Seasonal gaps: No fresh basil during winter months
- Quality variations: Not every harvest meets restaurant standards
Add a risk markup of 10-20% to your cost price for compensation.
How do you calculate the cost price of self-grown ingredients?
Gather all annual costs
Make a list of containers, potting soil, seeds, water, and maintenance. Depreciate containers over 3-5 years. Don't forget your own time (minimum €15/hour).
Estimate your annual harvest
Keep track of how many kilos you harvest per year from each plant. Include failed harvests in your average. Be realistic about seasons.
Calculate cost price per kilo
Divide your total annual costs by your total harvest in kilos. Add a 10-20% risk markup for failed harvests. This is your cost price for recipes.
✨ Pro tip
Track your container garden expenses and harvest weights for exactly 12 months. You'll discover the true cost per kilo and can make honest supplier comparisons.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
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Frequently asked questions
Do I really need to count my own time?
Absolutely. Your time has real value and you could spend it on revenue-generating tasks instead. Calculate at least €15/hour, but €25/hour reflects what you actually earn as an entrepreneur.
What if my self-grown ingredients cost more than buying them?
Then you know growing your own doesn't offer financial benefits. You can still do it for quality or marketing reasons, but factor the real costs into your menu prices.
How do I handle seasonal gaps in harvesting?
Calculate annual costs across the entire year, even if you only harvest 6 months. Your containers and time investment continue year-round, making your per-kilo cost higher than expected.
Should I add extra markup for crop failure risks?
Yes, build in 10-20% risk markup to your cost price. Failed harvests happen with homegrown ingredients, and successful crops need to compensate for the losses.
📚 Sources consulted
- EU Verordening 852/2004 — Levensmiddelenhygiëne (2004) — Official source
- EU Verordening 853/2004 — Hygiënevoorschriften voor levensmiddelen van dierlijke oorsprong (2004) — Official source
- EU Verordening 1169/2011 — Voedselinformatie aan consumenten (2011) — Official source
- NVWA — Hygiënecode voor de horeca (2024) — Official source
- NVWA — Allergenen in voedsel (2024) — Official source
- Codex Alimentarius — International Food Standards (2024) — Official source
- FSA — Safer food, better business (HACCP) (2024) — Official source
- BVL — Lebensmittelhygiene (HACCP) (2024) — Official source
- Warenwetbesluit Bereiding en behandeling van levensmiddelen (2024) — Official source
- WHO — Foodborne diseases estimates (2024) — Official source
Food Standards Agency (FSA) — https://www.food.gov.uk
The HACCP standards shown in this application are for informational purposes only. KitchenNmbrs does not guarantee that displayed values are current or complete. Always consult the FSA or your local authority for the latest regulations.
Written by
Jeffrey Smit
Founder & CEO of KitchenNmbrs
Jeffrey Smit built KitchenNmbrs from 8 years of hands-on experience as kitchen manager at 1NUL8 Group in Rotterdam. His mission: give every restaurant owner control over food cost.
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