How Do Alder Trees Influence Spruce Tree Growth?

How Do Alder Trees Influence Spruce Tree Growth

Spruce tree requires proper nitrogen-filled soil and companion plants to grow in health and vigor. But in some areas, mainly housing estates, soil condition is so poor, which is why these plants die prematurely. But Alder trees can promote these species to grow and thrive. So how do alder trees influence spruce tree growth?

Alder trees increase the nitrogen content in the soil and provide support to mainly spruce or conifer plants. And to get more insights into this plant’s impacts on spruce, have a read right now!

How Do Alder Trees Influence Spruce Tree Growth?

Alder has a high tolerance level that helps to provide support to its surrounding species. Any kind of alder plant locks nitrogen in its roots to enrich the soil conditions for spruce growth. And they prevent alders from dying by –

How Do Alder Trees Influence Spruce Tree Growth

1. Eliminating Weeds

As a companion plant, it takes up space around the spruce tree. This does not leave room for weeds to grow and block spruce growth. 

Weeds trigger infestation or pest attacks on plants, especially spruce trees which are vulnerable to insect diseases. But Alder does not let the weed pile up. As a result, the trees on the companion vegetation can grow their roots properly and without any root disease. 

2. Improving Soil Conditions

Large spaces of open soil can become too dry with time. It is more likely to happen in drought-prone regions. And Spruce is not drought friendly. So, to keep the species thriving, moist soil is a must.

Planting Alder trees around other plant species prevents the soil from becoming crumbly and erosion. It helps in seamless transpiration in pine trees or spruce.

3. Decreasing Diseases

Certain insects and pests can easily infest the Spruce trees or crops if they find larger space without any other vegetation layer around. Infestation triggers any plants to show symptoms of decay. Once the pests start habituating on the trunk or roots, it gets difficult to save the dying tree.

So, to keep the foliage and roots healthy, keeping these pests away is the way out. And Alder tree works as repellent against these unwanted guests.

Alder removes the direct patch for a few insects, such as beetles to live off Spruce nutrients. Thereby, a multicultural section of alder in between the spruces is a growing choice of plantations.

4. Attracting Pollinators

The seeds in the Spruce cones fall on the ground and promote new plants to grow. Some beneficial insects can fasten the process. 

And Alders attract these pollinators. The insects even help the lower branches to touch the ground and grow new stems. Watch the short video to get clarity on the process:

How to Plant Alder Trees for Spruce Growth?

Planting Alder trees in combination with Spruce is quite easy. All you have to do is go through the following things –

How Do Alder Trees Influence Spruce Tree Growth
  • Collect the seeds from the cones in May and keep them in an air-sealed bag with some wet peat moss. Rest the seeds in the fridge for 3 months.
How Do Alder Trees Influence Spruce Tree Growth
How Do Alder Trees Influence Spruce Tree Growth
  • Then, after the seeds fully mature, fill a bucket with soil and organic compost or fertilizers. 
  • Place the seeds above the surface in the bucket without covering them in soil or mulches. 
How Do Alder Trees Influence Spruce Tree Growth
  • Keep watering the seeds every day, and wait for them to grow saplings.
  • Once the sapling is of 3 months old, you can transplant it with the Spruce tree.
  • Dig the hole around the Spruce plants and remove the sapling from the bucket. But keep the soil attached to the root balls.
How Do Alder Trees Influence Spruce Tree Growth
  • Plant the root ball and cover the roots with soil. Tap the soil around to eliminate air pockets. 
  • Do not forget to water both the plants and watch how the Alder helps the Spruce to thrive. 

How to Care for the Companion Alder Tree?

Without nurturing the Alder tree, you cannot expect it to promote Spruce growth. So, for its maintenance, follow the given guidelines:

How Do Alder Trees Influence Spruce Tree Growth
  • Once the trees shed their leaves, prune the lower branches once a year. And cut down the intertwining branches.
  • Apply liquid or granular fertilizer during the early period of the tree plantation. Applying the solution thrice a year is a good deal. And place granules only once. 
  • Though Alders are less susceptible to tree diseases, apply fungal herbicide and insecticide once a year to prevent the disease from transferring to Spruce plants. 
  • Try to remove any debris around the Alder trees.
  • Avoid utilizing harsh chemicals right there. Because they are around the Spruce tree, the harsh layers can affect the Spruce. 

Frequently Asked Questions (F.A.Q’s):

Do Alder Trees Fight For SunLight With Spruce Trees?

Alder trees do require direct sunlight to grow. But its branches or foliage cannot cover light for Spruce trees if you prune them regularly.

Why Do Alder Plants Not Attract Pests?

Alders are high in Nitrogen. And it helps them deter insects and pests. As a result, it is a natural repellent for the Spruce tree.

Where Do Alder Trees Grow Mostly?

They thrive in moist soil along the stream-sides. Also, in sloppy areas, they tend to grow pretty well.


Hands down, alder trees top the list as a companion, especially for pine or Spruce growth. This is because alders lock the high nitrogen needed for the spruce. 

I hope our article on how do alder trees influence spruce tree growth has benefitted you. Do not forget to prune the branches of the Alders once they mature. Otherwise, they may affect the Spruce plants. 

Md Biajid

Meet Mia Biajid, a passionate nature lover. Particularly, he has a deep-rooted connection to the plant. Mia loves to spend time exploring forests and uncovering the secrets held within trees. He always inspires others to appreciate and protect our precious part of the ecosystem.

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