What is Pine Needle Mulch? Is It Safe? (Plus How to Use It)
Most pine trees can shed thousands of needles every year. Your first instinct might be to discard them to prevent them from increasing the acidity in your soil—at least that’s what many people say. But don’t toss it out, because that may be a myth!
Pine needle mulch, made of dried pine needles, is safe to use in the garden and does not increase soil acidity. To use it as mulch, gardeners can simply 1) gather the pine needles, 2) apply 2–4 inches of needles to the soil, and 3) replace them as needed.
Conifers and pine trees have been planted in yards for years to provide a nice, evergreen garden. The only problem with them is how many dead pine needles are left on the ground. The good news? You can make use of it and turn it into mulch!
How is Pine Needle Mulch Made? (And Busting Myths!)
Pine needle mulch consists of dried pine needles that can naturally accumulate underneath pine trees. Despite popular belief, pine needles do not increase soil acidity. Rather, they are widely used as a safe and excellent mulch in gardens.
Pine needle mulch is simply made up of dry and brown pine needles that have naturally fallen from a tree.
For countless years though, folks have been warned not to use it as mulch due to its high acidity. They were believed to bring down soil pH. But several studies have shown that this is a complete myth!
Pine needles are acidic when fresh and have an average pH of 3.5. Biologists have confirmed, however, that none of this acidity transfers to the soil once they are dry and fall off the tree.
Additionally, these dried pine needles have already decayed and barely have any acidity to transfer at all. Scientists have even confirmed that they make excellent mulch.
Despite what you might have heard about using pine needles, thousands of gardeners use them as mulch and agree that using them comes with plenty of benefits!
How to Use Pine Needle Mulch
When using pine needles for mulch, gardeners simply have to 1) gather the pine needles, 2) apply them to the soil, and 3) replace them as needed.
Pine needle mulch is one of the finest mulches that you can use. It’s one of my favorites for its clean look, compared to others like wood bark with irregular pieces. Here’s an easy guide for you to use as a reference when applying pine needle mulch in your garden.
1. Gather Pine Needles for Mulch
Pine needles can be collected for free or bought from stores and farms. Remove any debris from the needles before using them.
To use pine needles as mulch, start by gathering pine needles. Pine straw can be found for cheap at farms and stores.
But if you have access to a pine tree, you can gather as many dry pine needles as you need off the ground.
Pro Tip: Never take all the fallen pine needles from under a tree. This pine needle litter serves an important role in our environment. They form a protective barrier around the tree.
I always leave at least an inch of pine needles around the tree to ensure that the tree remains protected. Shake them free of any debris, and you’re good to go!
2. Apply Pine Needle Mulch to the Soil
Apply the pine needle mulch in 2–4-inch layers and use it on garden beds or borders. Use a rake to push them in place or spread it manually.
Depending on how much coverage you’d like, you can apply the pine needles in a layer that’s up to 4 inches thick. They should stay in place even when placed on slopes or exposed to strong winds.
Another great thing about using pine needle mulch is that slugs do not like climbing on the dry needles, so your crops are less likely to be eaten. Deer also dislike the rough texture of the pine needles.
On a dry and sunny day, spread the pine needles down in an even layer on the ground and rake them into place.
To make the pine needle mulch look even cleaner, you can brush the edges inwards with your hands to achieve a smooth and tidy look.
3. Replace Pine Needle Mulch as Needed
Because pine needles do not decompose very quickly, they do not need to be replaced often. Replace the pine needle mulch every season or whenever it decays.
If the pine needles aren’t cut, they can easily last for a few years. Since they take so long to decompose, you don’t have to worry about replacing them often.
Personally, I change my pine needle mulch every season to keep it clean and neat.
But if you live someplace with lots of rain or sun, your pine needle mulch might degrade faster. In this case, you can easily replace it with new pine needles when it starts to feel brittle or smell unpleasant.
The 4 Advantages of Using Pine Needle Mulch
Pine needles are ideal for mulch as they are 1) a free natural resource, 2) eco-friendly, 3) long-lasting, and 4) weed-free.
If you’re looking for a cost-effective and low-maintenance mulch, look no further. There are many situations where pine needle mulch can be used, as they have quite a few benefits!
Let’s quickly discuss the perks of using pine needle mulch for your garden.
1. Free Natural Resource
Pine needles are an abundant natural resource. Dried and fallen pine needles can easily be gathered for a free and natural mulch alternative.
What makes pine needles different from other mulches, like salt marsh hay or wood chips, is that they are free and widely available in many states.
Not only is it naturally derived, but pine needles can be found for free in abundance. I frequently offer to clean my neighbor’s garden with pine trees. In exchange, I take home the excess pine needles to use for mulch.
Pine straw can also be found in stores at low prices. But if you have any pine trees nearby, it can provide you with free and easy mulch every year whenever its needles drop.
All that’s needed is a bit of time and effort to collect the extra pine needles and you’re good to go!
2. Eco-Friendly
Unlike other natural mulches like salt marsh hay, pine needles are eco-friendly and can be harvested with little to no harm to the environment.
Mulches made out of plastic and rubber can be harmful to the environment, no doubt about that. Although there are plenty of natural mulches available, like bark and straw, this does not automatically mean that it is environmentally friendly.
Wood chips and salt marsh hay are indeed natural. But harvesting them from limited trees and marshes in mass quantities can damage the environment.
Due to the constant extraction of salt marsh hay, many salt marshes are predicted to disappear in 2050, and with it entire ecosystems for various life forms.
Explore this further in Is Salt Marsh Hay Good for Mulch?
On the contrary, there is no harm in gathering dried pine needles at all. A single conifer or pine tree can drop thousands of pine needles per year!
Rather than let this resource be lost in a waste dump, you can safely reuse the pine needles in your garden for years without any worry of harming any ecosystems.
3. Long-Lasting
Dried pine needles can be used as long-lasting mulch. They can last several years as mulch. A waxy substance on the pine needles protects them from bacteria and moisture and makes them suitable mulch to use in the garden.
There is no exact number of how long pine needles can last, but it can take years for them to decompose.
Pine needles have a waxy coating that shields them from water and bacteria.
Grass clippings for mulch can be convenient, but they tend to decompose within a few weeks. Some folks, however, have found that their pine needle mulch was still in good condition after 2 years!
Because pine needles do not retain any water, they’re also excellent at trapping moisture between the mulch and the soil, which is essential for seedlings.
In other words, pine needle mulch is not only low-maintenance. It can also help reduce how often you water, making your gardening process just a little bit easier.
4. Weed-Free
Unlike other mulches like hay, pine needles are sterile and do not contain any weeds. Additionally, pine needles cannot hold dirt, preventing weeds from growing inside.
Another great benefit of using pine needle mulch is that it is very clean compared to other mulches.
Weeds can be very resilient and can be found in mulches made of hay, straw, and even dirty wood chips. Pine needles, however, can’t contain dirt for weeds to root in. They simply don’t hold any weeds in general.
Besides the sterility of the pine needles, they can provide very dense coverage as a mulch and smother underground weeds from growing entirely.
For those who annually struggle with weeds in the spring, consider using pine needle mulch in the winter. Doing so will help prevent unwanted seeds from collecting on your soil and emerging in the next season.
The 3 Disadvantages of Using Pine Needle Mulch
The 3 drawbacks to using pine needles as mulch is that they 1) can potentially attract pests, 2) can be difficult to compost, and 3) are a potential fire hazard.
Pine needle mulch has great advantages, but there are some cases where it might not be ideal. Here are some downsides of pine needle mulch and what you should keep in mind.
1. Can Potentially Attract Pests
Thick layers of pine needle mulch can be attractive for pests like termites to hide underneath. Pine needles effectively keep out light and moisture, creating suitable environments for animals such as snakes and rodents.
Due to how long pine needle mulch can last and how effective it is at staying dry, it can provide an even more appealing home for pests like bugs and snakes.
Dampwood termites are attracted to moisture and can infest soils underneath pine needle mulch.
The termites probably won’t eat your pine needles. But that layer of mulch will help keep the ground damp and create the perfect environment for them.
As for snakes, there are plenty of species that can be helpful in the garden by eating unwanted pests. Garter snakes, for example, are great at eating mice and slugs.
But since pine needle mulch is perfect for bugs and potential rodents, it could serve as a great feeding ground for large and venomous snakes.
If neither of these creatures is normally found in your area, you could probably still use pine needles. But if they are, it might be best to avoid using it.
2. Difficult to Compost
Due to their slow decomposition rate, pine needle mulch is unsuitable for composting. The pine needles require more maintenance to compost and must be cut into small pieces beforehand.
In general, any water-resistant material will have slower decomposition. This is quite a drawback if you plan to use leftover pine needle mulch for compost straight away.
Remember, pine needles can take years to decompose. Because of this, it’s not a great material if you’re looking to make more black gold or compost.
Pro Tip: To make pine needle mulch compost friendly, cut it into small pieces with clean shears to expose the inner canals of the pine needles. Doing so will allow water and bacteria to get inside the pine needles, speeding up their decomposition.
Usually, this is what I do with my pine needle mulch before using it in my composting pile. Otherwise, pine needle litter can take more than 2 years to fully decompose.
3. Potential Fire Hazard
Pine needle mulch is very easy to ignite and can become a potential fire hazard in the garden. Avoid using pine needle mulch in areas with high heat or frequent fires.
Since pine needles do not retain any moisture whatsoever, this leaves them incredibly dry. Thick layers of dried needles are a potential fire hazard.
Christmas trees can go up in flames in less than 30 seconds despite being green.
Yes, these fires can happen even if the pine needles are still green. Dry and brown pine needles, however, are the most vulnerable to ignition.
Unfortunately, mulch is one of the most common reasons behind yard fires, especially in California.
As such, it’s best to avoid using pine needle mulch when fires are most likely. You should also consider avoiding them completely if you live in a fire-prone area.
Pine needle mulch may have a nicer aesthetic than mulch made of gravel or black plastic, but it could easily catch fire on a dry summer day. So be mindful of this and be sure to take extra caution if you decide to use this material!
FAQs
Is pine needle mulch safe for dogs?
When consumed, pine needles can cause vomiting and severe irritation in dogs as they travel through the digestive tract. Additionally, these needles can become a blockage. Such cases will require taking the dog to a veterinarian immediately, as this can be fatal.
Where can you get pine needle mulch?
Many pine trees shed their needles annually and are a free source of loose pine needles. Pine straw can also be found online or in pine tree farms, where millions of dried pine needles can be gathered.
Summary of Using Pine Needle Mulch
Pine needle mulch is typically made up of brown and dried pine needles and is widely used in gardens. Despite popular belief, it does not increase the acidity of the soil underneath it. As such, it can safely be used as mulch.
The pine needles can be collected from underneath pine trees or bought from farms. To use them as mulch in the garden, apply a thick layer of pine needles on top of the soil, and then replace them every season or whenever it starts to decay.
Benefits of using pine needle mulch include it being a free natural resource, eco-friendly, long-lasting, and weed-free. The downsides, however, are that the pine needles can potentially attract pests, are difficult to compost, and are a fire hazard.
Sources
- “Do pine trees and pine needles make soil more acidic?” by n/a in University of New Hampshire
- “Pine needles as mulch” by n/a in University of Washington
- “Mulch” by n/a in University of California
- “Types and Uses of Mulch in the Landscape” by Donald A. Rakow in Cornell University
- “Mulch” by Marjan Kluepfel and Robert F. Polomski in Clemson University
