Plant Spacing Calculator

Are you planning a landscaping project, or making your own raft boards? This plant spacing calculator will help you determine how many plants you need for an area, the planting grid and spacing, and even estimate the plants' purchase cost in seconds!

Plant Spacing Calculator

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How to use the plant calculator

You can figure out the plant spacing for your gardens and hedgerows using this plant spacing calculator.

First, select the type of planting you wish to plan: a garden or a hedgerow.

Let's start with the "Garden grid" option:

1. Select the type of grid: square, rectangular, or triangular.
2. Determine the width and length of the area you want to cover with plants. We will assume an orchard with a width of 240 m and a length of 320 m.
3. Determine the width of the border where you won't be putting plants. For our orchard, we will assume the border is 2 m.
4. Decide on the spacing, i.e., the space between the centers of the plants. Let's take 3.5 m for our example.
   • You can find the right spacing information on the seed packets or ask in your local plant nurseries or home garden center; or
   • You can estimate based on the target plant size and depending on the type of plant. If you want a 1 m wide spacing, you will plant at least 1 plant / m², unless you want the plants to overlap or grow faster.
5. The calculator will tell you how many plants you need. Notice that if you chose rectangular or triangular spacing, the plant spacing calculator will also tell you how much space you need to leave between the rows. Let's say we go for triangular spacing. We will be able to plant 7,059 plants, and the rows need to be spaced 3.03 m apart so that there is exactly 3.5 m between each plant in all directions. In triangular spacing, even rows will sometimes have one less plant, as shown in the image within the calculator. Don't worry. The plant spacing calculator will take this into account.
6. In the Advanced mode, you can estimate the cost of purchasing the plants you need for your planting project, given the total plants. Just input the total plants and cost-per-plant to get the total cost.

And here is how to proceed with hedgerows:

Select the Number of rows and choose if you want to find how many plants you need for a certain spacing requirement or the appropriate spacing for how you should arrange your plants, then:

• Input the Length of hedge and Plant spacing to get the total Number of plants you need for your hedge's length; or
• Input the Total plants and Plants per row to get the total Plant spacing you need for your hedge's length.

What is the formula for plant density? How to calculate plant spacing

Sometimes you may have a target plant density or plant population for a particular species (such as 2 plants per m2), and you need to find out how to calculate the plant spacing between each plant. The formula to find plant spacing from plant density is different depending on the type of grid.

For a square grid, the formula is:

plant spacing = √(1 / density)

and for a triangular grid, the formula is:

plant spacing = √(2 / (√3 × density))

where density could be plants/m2 or plants/ft2 and plant spacing could be m or ft, accordingly.

A fun fact about triangular spacing

Did you know that you might fit a different number of plants in the same area depending on which way you orient the triangular grid? Sounds bizarre, right?

You can try switching around your numbers for width and length to see how it changes the total number of plants. It makes a lot more sense when you can visualize the triangular grid in the diagram below:

Ways to orient a triangular grid over an area.

As you can see, turning the triangular grid by 90 degrees changes the grid layout. It can therefore result in a different number of plants since a triangular grid is not bi-symmetrical. If aesthetics are an integral part of your planning, try playing around with different grid orientations for different effects!

FAQ

How do I calculate the plant spacing in a square grid?

To calculate the plant spacing in a square grid:

1. Define the length l and width w of the surface to be planted.
2. Adjust these values with the eventual border.
3. Define the spacing between plants.
4. Divide the values of l and w by the spacing, round the results, and add 1 to each result to find the number of rows and columns of plants.
5. Multiply the number of rows and columns to find the number of plants.

What is the plant density?

The plant density is the multiplicative inverse of the square of the plant spacing. The plant density measures the number of plants per square meter, and we calculate it with the following formula:

d = 1/s²

where:

• d — The plant density; and
• s — Plant spacing.

Remember that plants lying in the corner of a grid cell account only as a "fraction" of a plant (half, a quarter): this is why, intuitively, it may look like the density is lower than it should be.

How many plants spaced 50 cm apart can I fit in a 3×2 m area?

Assuming no borders, you can plant 35 plants. To find this result:

1. Calculate the number of rows:
   Nr = 2/0.5 + 1 = 5
2. Calculate the number of columns:
   Nc = 3/0.5 + 1 = 7
3. Multiply the number of rows and columns to find the number of plants you can host in that area:
   N = Nr × Nc = 5 × 7 = 35

How do I calculate the number of plants in a row, with spacing?

To calculate the number of rows or columns (with an empty border), we use the following formula:

Nr = floor(width − (2 × border)) / spacing + 1

where:

• border — The empty space, taken two times because of its presence on both sides;
• spacing — The distance between plants; and
• floor — An operation that rounds down the result.