Grow a Garden Calculator Pro + Companions

1. Garden Bed Dimensions

2. Fertilizer Settings

3. Soil Test Results (ppm) (optional)

4. Add Crops

5. Crop & Fertilizer Plan

CropPlantsSeed CostYieldFert (oz)Remove

Planning a vegetable garden can be quite confusing, as you figure out how many plants will fit, how much fertilizer to apply, and how much water to give your crops. So, we’re left wondering. But imagine how you’d feel if you could get all the answers in less than 5 minutes, without any stress.

To that end, we’ve created the “Grow a Garden Calculator,” a 100% free, interactive online tool that will help you with your gardening:

  • Calculate your bed size and plant spacing
  • Estimate your harvest yield
  • Plan fertilizer and water needs
  • You’ll also get suggestions for your companion planting.

Let’s learn how to use it, how it works, and how this tool can save you time and money.

What Is the Grow a Garden Calculator?

Grow a Garden Calculator is a smart tool that runs on all browsers and requires no app downloads. It turns your garden ideas into a realistic, data-backed plan. Whether you’re growing tomatoes, lettuce, carrots, or zucchini, this calculator will tell you everything you need to know:

What You GetExample
How many plants fit48 tomato plants in a 10×4 ft bed
Total seed cost$24 for 48 seedlings
Estimated harvest68 lbs of fresh produce
Weekly water need336 gallons
Fertilizer schedule0.95 lbs/month (May, June, July)

And yes — it even includes companion planting tips like “Plant carrots with lettuce for better growth”.

How to Use the Grow a Garden Calculator (Step-by-Step)

Step 1: Enter Your Bed Size

  • Length (ft): 10
  • Width (ft): 4
  • Number of beds: 1

Total Area: 40 sq ft

Step 2: Choose Fertilizer Type

  • Synthetic or Organic
  • Select blend (e.g., 10-10-10)
  • Set cost per pound

Step 3: Add Your Crops

Click “+ Add Crop” and pick from:

  • Tomato
  • Lettuce
  • Carrot
  • Cucumber
  • Zucchini
  • And more!

Step 4: Get Instant Results

Click “Calculate Full Plan” See:

  • Plant count
  • Cost breakdown
  • Yield estimate
  • Monthly fertilizer schedule
  • Companion planting guide

Step 5: Export to PDF

Click “Export to PDF” → Download a print-ready garden plan!


Why This Garden Calculator Stands Out

Feature Benefit
Realistic Spacing Uses actual inches between plants
Smart Fertilizer Math Calculates N-P-K based on crop needs
Soil Test Integration Adjusts fertilizer if you input soil ppm
Companion Planting AI Warns against bad pairs (e.g., beans + peppers)
PDF Export Take your plan to the garden

Real Example: A 10x4 ft Beginner Garden

Crop Plants Cost Yield Fertilizer
Tomato 12 $6.00 96 lbs 18.2 oz
Lettuce 18 $9.00 9 lbs 7.2 oz
Carrot 144 $7.20 28.8 lbs 10.8 oz

Total Cost: $22.20 Total Harvest: 137.8 lbs Weekly Water: 336 gal Fertilizer (3 months): 2.85 lbs

Companion Tip: “Good: Carrots + Lettuce — carrots loosen soil, lettuce shades roots”

Pro Tips to Maximize Your Garden

  • Use compost → Reduce synthetic fertilizer by 25–50%
  • Mulch heavily → Cut water use by 30%
  • Rotate crops yearly → Prevent soil depletion
  • Plant marigolds → Natural pest repellent for tomatoes
  • Test your soil → Enter results to save on fertilizer

Our Final Thoughts

Whether you’re a first-time gardener or a seasoned pro, the Grow a Garden Calculator eliminates all the guesswork and helps you:

  • Save money on seeds and fertilizer
  • Grow more food in less space
  • Avoid common mistakes (like over-fertilizing or incorrectly pairing plants)

Start planting your garden the smart way.

Along with Grow a Garden Calculator, check other Free Clay Shrinkage Calculator from here.

Frequently Asked Questions

Is the Grow a Garden Calculator really free?

Yes! No sign-up, no ads, no paywall. Just open in your browser and start planning.

Does it work with raised beds or in-ground gardens?

Yes! Just enter your bed dimensions — works for any shape or size.

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