How To Keep Evergreen Trees Healthy: Ultimate Guide

Evergreen trees are beautiful year-round, but they need help to stay healthy. While evergreens drop some needles yearly, their branches shouldn’t become too thin. You’ll need to know how to properly care for these trees to ensure that they thrive.

You can keep your evergreens healthy by fertilizing, mulching, and watering (among other things). You may need to prune them occasionally. You need to know where to plant your evergreens so they get enough sun, and what soil conditions will help them grow.

As long as you follow this guide, your trees are sure to stay happy and healthy. Below, I’ve covered the proper steps to care for your evergreens. Although different evergreen species (and even different trees!) may have their individual requirements, some general guidelines apply.

1. Fertilize Your Evergreen

You don’t need to fertilize your evergreens too often. If you do, it could cause fertilizer burn. Evergreens need less fertilizer than other types of trees, so you want to be careful during applications. It’s a good idea to start with a soil test to see what nutrients are missing.

A soil test allows you to determine how fertile your soil is, so you know if your plants can pull enough nutrients from the ground to stay healthy. While they can test for various vitamins and minerals, you want to choose a test that covers nitrogen, phosphorus, and potassium, at least. You should test your soil once every two to three years or so, although you can always check if your plants grow slower than expected. 

An excellent DIY soil testing kit is the Luster Leaf Professional Soil Kit from Amazon.com. It has detailed, easy-to-follow instructions and a convenient case to keep everything. Plus, you receive 80 quality tests for checking nitrogen, phosphorus, and potassium levels and pH tests.

You should only fertilize your pine trees when they appear to drop more needles than usual, the branches look thin, or you see other signs of slowed growth. The needles might also look dull or short, indicating that the tree isn’t getting enough nutrition from the soil. You’ll want to conduct a soil test if the trees are becoming unhealthy to determine if you need to apply fertilizer.

When To Fertilize Your Evergreen

You should fertilize your evergreen before it experiences a growth burst. The best time to do so is between June and the middle of July. After that point, fertilization can cause new growth that won’t survive past the winter, and your trees might not absorb the nutrients well, among other issues.

Many landscapers also recommend fertilizing your evergreens in the winter to boost their growth during the spring growing season. They’ll receive much thicker, greener needles, which look beautiful.

However, you’ll also want to apply fertilizer if your pine tree isn’t healthy. If it’s recovering from harm from disease or pests, the fertilizer can help speed up the tree’s recovery. You might only need to apply fertilizer some years if your trees are always healthy.

Finally, ensure you don’t apply fertilizers during droughts. The fertilizer can make it harder for your tree to absorb the water it needs, causing it to dry up and drop needles excessively. You should also wait to use fertilizers if you recently relocated the tree so you don’t cause it more stress.

How To Fertilize Your Evergreen

First, you need to choose a reliable fertilizer your pine trees will love. The best options for evergreens use an NPK ratio of 10-8-15, meaning the fertilizer consists of 10% nitrogen, 8% phosphorus, and 15% potassium. 

Once you have a quality fertilizer, there are two ways you can apply it:

  • Spread the fertilizer over the soil. This method is the most common. You can sprinkle a generous amount of fertilizer over the ground around the tree. This process is the same as fertilizing a lawn or garden. You need to water the area thoroughly to help the fertilizer soak into the soil, where the tree can absorb it.
  • Dig small holes around the tree. You can also dig small holes, about an inch to two inches long (approx. 1 to 5 cm), around the tree. They should be at least a foot (0.30 m) deep and far apart. Fill the gaps with fertilizer, then water the area well. This method is best for trees with yellowing needles, slowed growth, or other signs of nutrient deficiencies. 

You’ll want to use between two and four pounds (0.91 to 1.81 kg) of nitrogen for every 1000 square feet (93 square meters) of soil around the tree for rapidly growing pines. After their growth slows, you can use a pound (0.45 kg) of nitrogen instead.

2. Use Mulch on Your Evergreen 

You should also use mulch on your evergreen now and then. Although mulch provides the soil with fewer nutrients than fertilizer, it’s nevertheless perfect for keeping the ground rich in nutrients and moisture by trapping them there. This ensures the soil conditions are ideal for your trees.

You’ll want to choose finely mulched oak or pine for your evergreen trees. Then, you can apply it using the following steps:

  1. Wait until early spring.
  2. Remove any debris from under the evergreens using a rake. Make sure to pull out any weeds as well.
  3. Water the ground around the tree thoroughly.
  4. Spread the mulch under the tree in a large circle. It should be even and two to three inches (5 to 7 cm) deep, ensuring the mulch doesn’t make contact with the base of the tree.
  5. Apply a second layer of mulch towards the end of the fall.

You can apply mulch soon after using fertilizer to trap the nutrients in the soil. If you apply the fertilizer after mulch, you’ll need to spend more time watering the area so the fertilizer can seep into the ground.

Can Evergreen Leaves Be Used As Mulch?

You might wonder if you can use the pine needles as mulch since they’re already surrounding the base of your evergreens anyway.

Evergreen leaves can be used as mulch, but it is less effective than leaves or bark because the needles do not break down as quickly. Still, they do not block water from entering the earth and will not compact too much, which is beneficial.

So, you can use the needles as mulch, but there are better options if you’re trying to keep your tree healthy. Plus, if the tree’s already dropping large amounts of needles, it needs more nutrients or water. You’d get better results making those changes first before worrying about using the needles as mulch.

Many gardeners also like to collect pine needles and use them as mulch in their gardens. However, you’ll need to monitor the soil’s conditions to ensure the mulch benefits your garden.

3. Water Your Evergreen

Generally, you want to ensure your evergreens receive around two inches (5 cm) of water each week, whether you water them yourself or rely on the rain to do so. Most landscapers water their trees thoroughly one to two times a week and get excellent results.

Younger trees also need more water than established pines to keep them healthy as they grow. Water them one or two more times per week to ensure they receive enough moisture to spread their roots underground.

You only need to water up to the tree’s drip line, where the tree canopy drips water when it rains. 

Lastly, water the pine trees more frequently during dry spells.

Giving your evergreens enough water is essential. You can tell that your watering routine is off if the trees start dropping needles excessively. The best way to know if you’re over or under-watering is to check the ground.

Squishy soil and excessive needle-dropping mean you’re overwatering the tree. The sudden appearance of mushrooms can also mean the area’s too wet. Overwatering can be just as destructive as underwatering to plants, leading to root rot and other problems, so it’s essential to get it right. 

On the other hand, dusty, dry soil and needle-dropping show that the tree needs more water. You can increase the amount of water you give the tree or water it an additional time each week.

Overall, it can take some experimentation to water your evergreen trees properly. You’ll want to keep a close eye on the trees any time you adjust your watering routine so you can see how those changes impact the evergreens’ health.

Do Evergreens Require a Lot of Water?

Evergreens require a lot of water, especially before winter. They can store moisture in their roots to keep them healthy during this period. You should water your evergreens at least once or twice a week, giving them a few inches of water at a time. Deep watering keeps the roots in good condition.

Pine trees generally need a lot of water, but several factors can impact how much you need to water them. If your area is very dry for multiple weeks, you’ll need to increase watering to keep the trees healthy. It’s essential to monitor your tree for signs it needs more moisture so you can act accordingly before it starts drying up and dropping all of its needles.

After watering your evergreen a few times, you’ll get a better feel for how much it needs. Various soil conditions and the tree’s age can impact how often you water it.

4. Prune Your Evergreen

Occasional pruning can also keep your evergreens healthy. During pruning, you remove dead or sick branches, allowing the rest of the tree to put more energy into its already healthy branches. Plus, pruning also encourages new growth.

You’ll want to wait until after the late summer or early fall to prune the evergreens. Pruning too close to the start of winter will cause the tree to form new branches that are too weak to survive the cold. The new growth needs more time to become established before winter starts. So, spring or early summer is the best time to prune evergreen trees

During pruning, you should cut away any dead branches you find, making sure to go back to the healthy part of the tree. You can also remove any out-of-place branches that cross to make the tree look nicer.

This YouTube video covers when and how to prune your evergreens in more detail:

5. Maintain Your Evergreen’s Preferred Conditions

There are multiple considerations when growing healthy evergreens. You’ll want to ensure that the trees have consistent and ideal pH levels and receive enough sunlight.

You can always make changes if the current conditions don’t suit your evergreens very well.

Evergreens and Soil pH

You’ll also want to maintain the evergreen’s preferred soil conditions. Doing so makes it easier for the tree to absorb and use nutrients, keeping it healthy. Sometimes, your soil has enough vitamins and minerals for the trees to thrive, but the pH levels make it difficult for your evergreens.

Most evergreens prefer to live in acidic soils, meaning they have a lower pH level. Before making changes, you’ll need to test the ground to see its current pH. If it’s too high, you’ll want to lower it.

Generally, most evergreen trees want a pH of 5.5 to 6.5. When the soil’s pH gets too far out of that range, it makes it much harder for the tree to absorb the nutrients it needs to stay healthy.

To learn more about evergreens and soil pH, you can check out my other article: Do Evergreens Make Soil More Acidic?

Evergreens and Sunlight

Most evergreens want to live in full to partial sunlight, so they will be less healthy if you leave them in the shade all the time. However, some can do well in darker conditions, so you’ll need to check the species of your evergreen.

If the tree is small enough, you can relocate it somewhere it gets enough sunlight. You’ll want to water the tree more often after replanting it to encourage it to spread its roots deeper into the soil. Evergreens can become stressed after you move them, so you might notice them dropping more needles for a while.

Some landscapers also use mirrors to help redirect light onto their established trees. You would only need to do this sometimes, as evergreens don’t need as much sun in the winter. You could also paint any nearby surfaces white since doing so would help redirect light onto the evergreen.

Evergreens that don’t receive enough sun can drop their needles rapidly, making their branches look bare. The needles might also turn yellow or brown and look dry. Watering and nutrient issues can also cause these problems, so make sure to try solving those other issues first.

Evergreens and Soil Drainage

It’s also important to consider soil drainage when accounting for an evergreen’s preferred conditions. The soil should be well-draining yet still able to hold onto moisture well.

You’ll need to add compost to sandy, arid soil to make it retain more water. Conversely, soil full of clay needs more drainage, which you can increase in various ways. For example, you can put sand in the bottom of the planter for better drainage.

Checking the soil frequently can tell you if you’re making the right changes. You’ll notice that the ground feels a bit more squishy or solid, depending on if you’re increasing or decreasing the soil drainage around the tree.

Overall, getting the soil drainage right can help your evergreens stay healthy. It prevents root rot due to excessive moisture while keeping the ground wet enough so the tree gets enough to drink. You must find a nice balance with the drainage in your soil for those reasons.

How Much Space Does an Evergreen Tree Need?

It’s also vital that your evergreens aren’t too crowded together. If they’re too close, they’ll compete for resources in the soil, causing some of your trees to become very unhealthy while others do just fine.

Evergreens need at least 10 to 12 feet (3 to 3.6 m) of space around their base. Some species of evergreens, such as junipers and cedars, need slightly less space to thrive at about six feet (1.8 m). Consider how close your trees are to each other and if you should relocate some of them.

Generally, you want to ensure your evergreen trees have ample space, especially if they’re still unestablished. The more room you can offer them, the better off they’ll be.

Conclusion

There are multiple steps you’ll need to take to keep your evergreen trees healthy. Proper maintenance can include regularly fertilizing, mulching, and watering around the tree. Plus, you’ll need to prune occasionally while keeping the soil in good condition for the tree.

That might seem like a lot of work, but evergreen trees are low maintenance compared to other trees. You’ll get a feel for caring for your evergreens in no time at all when you follow this guide.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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