Landscaping your home garden is hard work but generally very rewarding. Coming up with a plan prior to starting your gardening journey will ensure the proper placement of trees, shrubs, and other plants. It is possible to plant trees too close together. It can cause a battle for resources and space. If you’re planting more than one tree in your garden—as most homeowners do—you will need to ensure ample space is left between them. When considering how far apart to plant trees, it’s essential to consider their mature size and growth patterns to create a harmonious and thriving landscape.
So how do you determine how much space is needed? Below are some pointers on making sure you allow enough space for your saplings to thrive.
When you plant trees together, they require plenty of space to spread their branches above and roots below. A number of problems arise if you plant trees too close together.
Table of Contents
How far apart should trees be planted?
So how much space should be left between trees? Well, the answer depends on the type of trees being planted. Smaller trees, such as dogwoods or sumac trees, require less space than larger varieties, such as redwoods and walnut trees. Here are some examples:
| Fully grown tree size | Example species | Distance from other trees |
| Small – 6′ – 20′ | Plum, Japanese Maple, Dogwood, Cherries, Peaches, Hawthorn, Rowans, Crab Apple | 5′ – 12′ |
| Medium – 20′ – 40′ | Eastern Redbud, Saucer Magnolia, Golden Chain, Mimosa, Dwarf Alberta Spruce, Japanese Stewartia | 12′ – 30′ |
| Large – 40′ – 60′ | White Horse Chestnut, Sapporo Elm, Golden Alder, Sweet Chestnut, Hornbeam, Greenspire Lime | 30′ – 50′ |
| Very large – 60′ and above | Douglas Fir, Common Alder, Western Red Cedar, Standard Horse Chestnut, Kaiser Lime, Maidenhair | 40′ – 50′ |
Smaller trees are considered trees that grow up to 20 feet in height. These trees require approximately 6 to 12 feet of spacing. Medium trees, such as hemlock and blue spruce, grow to be between 30 and 70 feet. These trees require 30 to 40 feet of spacing. Large trees are considered to grow up to 70 feet or more. Large trees require at least 40 to 50 feet of spacing. Find more information on plant and tree sizes on the Gardens World website.
Sunlight requirements
Having trees packed together creates a canopy of leaves above that blocks sunlight, causing both trees and the plant life below to work extra hard to try to reach the sunlight they need. This leaves no energy for flower production or fruiting. It also makes trees weaker, and you might notice a strange growth pattern since they are branching out in all directions, trying to find some sunlight.
Smaller trees will be left with no sunlight at all, and the grass and any plant life below can die off due to lack of sun. Having trees spaced out will allow for sunlight to reach the tree trunks, and smaller trees will have access to sunlight to grow strong.
Importance of water
Trees will also compete for water when planted tightly together. Especially in arid conditions, trees need to be spaced far enough apart for there to be enough soil moisture to support each tree’s growth. When trees are spaced in proximity, there may not be enough moisture to spread to all the trees.
Infestations and disease
When trees are planted too close together, the lack of air circulation can cause mold and mildew to form on trees. If the branches and leaves are close enough to touch neighbouring trees, the mold and mildew can spread between trees.
Weakened trees are also more susceptible to infestations of tree mites, aphids, and other pests. As with disease, if trees are touching, pests will be able to spread between them more easily.
Diversity in Species
Diversifying the tree species in your garden can enhance its resilience against pests and diseases. Mixing different tree types also adds visual interest and creates a more vibrant and dynamic landscape.
Imagine you have a large backyard with a variety of fruit trees, including apple, cherry, and pear trees. However, due to the close proximity and lack of diversity, an outbreak of aphids occurs, rapidly spreading from one tree to another. Since the trees are of the same species, the aphids find an abundant and suitable food source, leading to significant damage.
Now, let’s consider a different scenario where you’ve intentionally mixed tree species in your garden. Among the fruit trees, you’ve also planted some native oak trees, maple trees, and evergreen spruces. When an aphid infestation hits, it primarily targets the fruit trees. However, the presence of oak trees and spruces creates a natural barrier and reduces the spread of pests. The diverse plant community acts as a deterrent, limiting the severity of the aphid outbreak and preserving the health of your entire garden.
Importance of creating a sunny garden
Part of the joy of having a yard is the ability to sit outside and enjoy the space, soaking up some sun rays and enjoying the breeze. When trees are planted so close together that the entire yard is in constant shade, this can make your yard a dark, mildew-ridden, dreary place to spend time.
Mold can grow more quickly on patio furniture and pathways without sunlight and air circulation, making the patio upkeep more labor-intensive. Plants and grass will struggle to survive without access to the sun. By spacing out your trees and allowing the sunlight to penetrate the canopy above, your yard will be a more welcoming place to enjoy spending time.
Consider future growth
Always plan for the mature size of the trees when spacing them. Some trees might appear small when planted, but they can grow significantly larger over the years. Avoid the temptation to pack trees closely together based on their current size, as this can lead to problems later on. Understanding the species and potential growth is very important.
Proper pruning
Proper pruning is a fundamental aspect of tree care that plays a vital role in maintaining healthy trees and managing overcrowding within the canopy. Regular and thoughtful pruning practices contribute to the overall health, appearance, and longevity of mature trees. Here’s an in-depth look at the significance of proper pruning and its various aspects:
Deadwood Removal: Pruning away dead, diseased, or damaged branches is essential for maintaining tree health and safety. Deadwood can be a breeding ground for pests and diseases, and it poses a potential hazard as it becomes more susceptible to breakage during storms or strong winds. By promptly removing dead branches, the tree’s energy can be redirected towards promoting new growth and overall vitality.
Thinning the Canopy: Thinning the canopy involves selectively removing specific branches to reduce the density of foliage within the tree’s crown. Overcrowded canopies hinder air circulation and sunlight penetration, creating an environment conducive to fungal growth and other diseases. Thinning helps open up the tree’s interior, allowing air and sunlight to reach inner branches, which in turn promotes better photosynthesis and a healthier overall structure.
Crown Cleaning: Crown cleaning involves removing branches that are crossing, rubbing, or competing with one another within the canopy. As branches intertwine, they can create wounds and damage bark, providing entry points for pathogens. By eliminating such branches, the risk of disease and infestation is reduced, and the tree’s structural integrity is preserved.
Size Reduction: In some cases, mature trees may have outgrown their allotted space, causing them to interfere with structures, utility lines, or other trees. Size reduction pruning can help manage the tree’s growth and prevent further overcrowding. When executed properly, this type of pruning retains the tree’s natural form and aesthetics while reducing its size to fit its surroundings better.
Directional Pruning: Pruning with a specific direction in mind helps guide the tree’s growth and shape. By strategically trimming branches, arborists can influence the tree’s form, encouraging upward or lateral growth as desired. This practice is particularly valuable for trees planted in confined spaces or near buildings, as it directs growth away from potential obstructions.
Seasonal Timing: The timing of pruning can significantly impact tree health. For deciduous trees, pruning is best done during the dormant season (winter), as it minimises stress on the tree and allows it to focus its energy on healing wounds and new growth in spring. Conversely, for flowering trees, pruning is typically done after they have finished flowering to avoid disrupting the following season’s bloom.
Professional Pruning: Proper pruning requires a deep understanding of tree biology and pruning techniques. It is advisable to seek the expertise of a certified arborist for large or complex pruning tasks. An arborist will carefully assess the tree’s health, growth patterns, and specific needs, ensuring that pruning is conducted with precision and minimal impact on the tree’s overall well-being.
Try incorporating these various aspects of proper pruning, then you can ensure that their mature trees remain in optimal condition, contributing to a safe, visually appealing and thriving landscape for many years to come. Regular pruning not only promotes the health of individual trees but also enhances the overall beauty and harmony of the entire garden.
Battle for nutrients
Soil contains a limited amount of nutrients. Trees need to absorb these nutrients to grow strong. When trees are planted too close together, they end up in a battle for survival. Having trees that are nutrient-deficient means you need to supplement the soil with extra fertilisers to help them grow, which still doesn’t guarantee their survival.
It’s best if you’re able to plan ahead and leave enough room between each tree when planting. Nutrient deficiencies can cause long-term problems, such as trees that are unable to grow properly, are unable to produce fruits or flowers, or have weakened branches and yellow leaves.
Soil testing
For those who wish to get technical with tree spacing, soil testing is a crucial step in preparing your garden for tree planting, as it provides valuable insights into the soil’s composition and fertility. By understanding the soil’s nutrient content and pH levels, you can make informed decisions about the types of trees that will thrive in your garden and take appropriate measures to improve the soil conditions if necessary.
Here’s a little more detail regarding the soil testing process and its significance in creating an optimal environment for your trees:
- Collecting Soil Samples: Before conducting a soil test, it’s essential to collect representative soil samples from different areas of your garden. Each sample should be taken from the top 6 to 8 inches of soil. Use a clean spade or shovel to dig small holes, and take multiple samples from different locations within the planting area. Mix these samples together in a clean bucket to create a composite sample.
- Choosing a Testing Lab: Once you have your composite soil sample, you can send it to a reputable soil testing laboratory. Many agricultural extension offices or garden centres offer soil testing services, or you can find private laboratories that specialise in soil analysis. Choose a lab that provides comprehensive testing, including nutrient analysis and pH levels. The Soil Association is a great resource for more information.
- Understanding Nutrient Content: The soil test results will indicate the levels of essential nutrients in your soil, such as nitrogen, phosphorus, potassium, calcium, magnesium, and others. These nutrients play a crucial role in supporting plant growth and development. The test will reveal whether your soil has adequate levels of these nutrients or if there are any deficiencies that need to be addressed.
- Interpreting pH Levels: Soil pH is another critical factor in determining the suitability of your soil for specific tree species. The pH scale ranges from acidic (pH below 7) to alkaline (pH above 7), with 7 being neutral. Different trees prefer different pH levels, so understanding your soil’s pH will help you select trees that are well-suited to the existing conditions.
- Addressing Nutrient Imbalances: Based on the soil test results, you can take targeted actions to address any nutrient deficiencies or imbalances. For example, if your soil lacks phosphorus, you can add phosphorus-rich fertilisers before planting to ensure adequate nutrient availability for your trees. Similarly, if the soil is too acidic or alkaline for your desired tree species, you can amend the pH levels with suitable materials like lime (for acidic soil) or sulfur (for alkaline soil).
- Optimising Soil Structure: In addition to nutrient content, the soil test can provide information about the soil’s texture and structure. Sandy soils drain quickly but may require more frequent watering, while clay soils hold moisture but can become waterlogged. Adding organic matter like compost can help improve soil structure and enhance its water-holding capacity and nutrient retention.
When conducting a soil test and taking appropriate corrective measures, you create an ideal foundation for your trees to flourish. Tailoring the soil conditions to the specific needs of your chosen tree species will promote healthy growth, vibrant foliage, and bountiful fruits, ensuring a successful and rewarding gardening experience.
Tree removal
If you’re already dealing with mature trees that are too close together, you can decide to remove some of the trees in order to provide a better chance of survival for the remaining trees. By removing the trees that aren’t thriving, and others if more space is needed, you can ensure a better survival rate for the rest of your trees. This will provide your yard with more sunlight and better air circulation. The remaining trees will have more access to nutrient-rich soil and abundant water, instead of having to fight for whatever they can get. If you can remove or transplant some of the trees while they’re still young, it’s easier and more cost-effective.
Contact Mr. Tree for assistance with your tree removal. They can help decide which trees are the best to remove and safely thin the number of trees in your yard to a manageable and healthy number.
If you’re considering planting trees in your yard, be sure to create a plan prior to planting. There are many smaller versions of larger tree varieties available if you’re landscaping a smaller space. Don’t forget to review the tree spacing guide, then consider what the mature size of the tree will be. Once the mature size of the tree is determined, be sure to leave ample room between saplings to ensure a healthy and thriving yard for years to come.
Take a look at some more great garden posts: