Planting a tree is one of the simplest ways to make a lasting, positive impact on your local environment. In return for a modest outlay and just a few minutes of work, you can enjoy decades of flowers, fruit, and autumn colour. However, while tree planting might seem like an easy task, scientific research has revealed some surprising facts that can make a big difference to the health of your tree. One of the most important lessons? It’s better to plant trees in square holes, not round ones.

For years, gardeners were taught to plant trees in round holes, as this seemed like the most natural choice, given that trees have round trunks and canopies. However, this method often leads to problems for the roots.

"Autumn is a second spring when every leaf is a flower.”

Albert Camus

The Traditional Round Hole Approach

When a tree is planted in a round hole filled with rich, fertile compost and fertiliser, the roots quickly begin to spread out into the soft, nutrient-rich soil. Initially, this results in healthy growth and a strong start for the tree. But the problems start when the roots hit the harder, more compacted soil around the edge of the hole. The roots will instinctively follow the edges of the hole, spiralling around the perimeter in search of more space and nutrients.

This creates a circular root system, similar to what happens when plants are grown in containers. Over time, the roots form a tight, hardened ring, which can choke the tree. As the roots grow thicker, this ring constricts the tree’s ability to absorb water and nutrients, eventually leading to stunted growth or even the death of the tree.

The Square Hole Solution

The solution to this problem is surprisingly simple: plant your tree in a square hole instead of a round one. Research and planting trials have shown that roots struggle to grow around sharp corners. When a tree is planted in a square hole, the roots reach the 90-degree corners and are forced to spread outward rather than spiral. This encourages the roots to grow into the native soil surrounding the hole, where they can establish themselves more easily.

"No occupation is so delightful to me as the culture of the earth, and no culture comparable to that of a garden.".

Thomas Jefferson

Square holes have been shown to reduce the risk of the circular root system developing, which means your tree will have a better chance of thriving. In addition, square holes help trees establish more quickly, making them better able to withstand environmental challenges such as droughts.

Interestingly, square holes are also easier to dig with a spade. Since most spades have flat blades, digging a square hole requires less effort than cutting a perfectly round one. So, by switching to square holes, you're not only improving the health of your tree but also saving yourself some work!

Additional Tips for Tree Planting Success

If you want to further improve the chances of your tree’s success, consider these additional tips:

• Avoid Rich Compost: Instead of filling the hole with rich organic matter and fertiliser, use the soil you’ve dug out of the hole. This prevents the "container effect" that can stunt root growth and encourages the tree to adapt to the surrounding soil conditions.

• Prune Twisted Roots: Before planting the sapling, prune any twisted or matted roots at the edges of the root ball. While this may feel harsh, it actually stimulates the tree to produce compounds that encourage new root growth, helping the tree establish more quickly.

By following these steps, you can boost your chances of success and give your tree the best start in life. So, when planting your next tree, skip the round hole and opt for a square one – your tree will thank you!

Vocabulary List:

1. Sapling (noun) –  A young tree, typically just a few years old.
   • Example: Are there any saplings in the garden.
2. Root ball (noun) –  The mass of roots and soil around the base of a tree or plant.
   • Example: Yes, the plant has a root ball.
3. Fertile (adjective) –  Rich in nutrients, capable of supporting plant growth.
   • Example: The fertile coastal plain.
4. Compacted soil (phrase) –  Soil that is densely packed, making it harder for roots to penetrate.
   • Example: Damp soil is usually already a well compacted soil.
5. Prune (verb) –   To trim or cut away dead or overgrown branches or roots.
   • Example: Now is the time to prune roses.
6. Backfill (verb) –  To refill a hole or trench with earth or material. country.
   • Example: They backfill the hole to street level.
7. Container effect –  A phenomenon where plant roots become confined in a circular shape due to being grown in pots or confined spaces.
   • Example: Lets use the pot for the container effect.
8. Establish (verb) –  To make a tree or plant grow strong and healthy in its new location.
   • Example: I needed help from a friend to establish myself at my workplace.
9. Drought (noun) –   A prolonged period of abnormally low rainfall, leading to water shortages.
   • Example: I asked for something to slake my drought.
10. Spade (noun) –   A tool used for digging, typically with a flat blade.
    • Example: I work all day with my shovel and spade.

Discussion Questions and Topics:

1. Why is it better to plant a tree in a square hole rather than a round one?
2. What can happen to a tree’s roots when planted in a round hole with rich compost?
3. What other methods can you use to help a tree establish itself quickly?
4. Have you ever planted a tree before? If so, how did it go?
5. Do you think planting trees is important for the environment? Why or why not?
6. If you could plant any type of tree in your garden, what would you choose and why?
7. How do you feel about the idea of using square holes for planting trees?
   • Does it sound like a helpful change to you?