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Bulb Spacing Calculator

Table of contents

A bit about garden bulbsHow to use the bulb spacing calculatorWhat bulbs to plant in fall?What bulbs to plant in spring?FAQs

No matter how green your thumb is, you can save yourself a lot of trouble calculating how many flower bulbs you can fit in your garden with this bulb spacing calculator. Whether you're interested in crocus bulbs, tulip bulb spacing, or any other perennial bulbs, this tool will be invaluable to you. To make things even easier, we've also included additional information about the most common garden bulbs, such as their planting depth and their potential dimensions. We also let you know when you should plant the bulbs, so you'll know what bulbs to plant in the fall, what bulbs to plant in spring, and when to plant daffodil bulbs. Now, let's get gardening!

🔎 If you wish to plant in hedgerows, we have a dedicated plant spacing calculator.

A bit about garden bulbs

Bulbs are quite a common sight around the world as many different species of plants employ them as winter stores of energy. As winter approaches and the days get darker, plants have less time to use light to photosynthesize. This lack of energy means they may not be able to sustain themselves and can die. To prevent this, some plants have developed special areas to store a portion of the energy gathered throughout the rest of the year for use over the winter months. This is known as a garden bulb.

Bulbs are really just specially adapted parts of the plant's stem surrounded by layers of leaves or leaf bases (this is why an onion has layers). All of this energy is very tasty to many animals (especially squirrels), so, in an attempt to hide their winter lifeline, plants usually store the bulbs underground. Since the plant grows from the bulb next season, most bulbs are perennial bulbs.

It is possible to propagate bulbs to get more! Sometimes the plant grows new bulbs next to the original one automatically, while other times, seeds are required to start new plants. Gardeners can also propagate plants from cuttings to speed up the process or 'chipping' a bulb into several pieces. This is how you can get a load of easy-to-grow bulbs to use with this bulb spacing calculator.

How to use the bulb spacing calculator

Using the bulb spacing calculator is extremely easy. Just follow these steps:

  1. Select which planting grid you'd like to follow. We have two options for you to choose from, rectangular (which can be square) or triangular.
  2. Provide the area of your gardening bed. If it is rectangular, you can input the length and width of the sides into the first section of the tool. We need to exact size of the length and width of the planting bed to correctly compute the number of rows you can fit in your garden. You may also specify the border between the plants and the bed's edge.
  3. Pick your chosen flower bulb from the drop-down menu (e.g., crocus bulbs). This will change the number in the Plant spacing (s) field. If you can't see the one you want, enter the known spacing into the Plant spacing (s) field. You may also need to provide the space between each row.
  4. Read the number of plants you need to correctly fill your space at the end of the calculator!

No worries if you don't own a garden. Some of these will grow to be just as vibrant in a planter. With our potting soil calculator, you'll know exactly how much soil you need.

What bulbs to plant in fall?

The bulbs you can plant in fall are:

  • Alliums;
  • Anemone;
  • Bluebells;
  • Crocus;
  • Cyclamen;
  • Daffodil;
  • Fritillaria;
  • Hyacinths;
  • Iris;
  • Muscari; and
  • Tulips.

What bulbs to plant in spring?

The bulbs you can plant in spring are:

  • Anemone;
  • Cyclamen; and
  • Snowdrops.

What are some easy to grow bulbs?

Some easy-to-grow bulbs include:

  • Daffodils;
  • Hyacinth; and
  • Tulips.

What flower bulbs can be planted in January?

The only flower bulbs that can be planted outside in January are tulip bulbs, and that is only if the ground is not frozen. Alternatively, you can plant most autumnal bulbs inside in January; just place them somewhere cool and dry and don't forget about your tulip bulb spacing!

When to plant daffodil bulbs?

Daffodils should be planted in early autumn, ideally September, for the best results.

Rectangular plant spacing grid.

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Plant information

Type: Perennial
Height: 30-90 cm (12-36 in)
Width: 8-10 cm (3-4 in)
Spacing: 10 cm (4 in)
Plant in: Mid-summer to early autumn
Flowers in: Spring or early autumn
Plant likes: Full sun, semi-shade, and moist soil

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