|Close up on freshly scattered pine straw mulch - love the texture and the color!|
Before I became a gardener, I never gave mulch much thought. It was just that stuff lying on the ground underneath bushes.
But once I started gardening, I realized what a crucial role mulch plays in the home landscape. If you don't have mulch, you've got bare ground. And unless you're putting down chemical herbicides (which I don't) bare ground is like giving weeds a big "SPACE AVAILABLE HERE" welcome sign.
Mulch plays a couple of other valuable roles too. Organic mulches - which in this neck of the woods typically means pine bark mulch or hardwood mulch - break down over time (some kinds faster than others) and add organic material to the soil. This is particularly important if you're working with heavy crap - I mean heavy clay - soil to begin with. The more organic matter you can add to condition the soil, the better.
And of course, mulch can play an important insulating role too - keeping the plant's roots warmer in winter (particularly important if you like to push zonal limits in your choice of perennials) and cooler in the summer. Where unmulched soil quickly bakes to concrete in the summer Tennessee sun, mulched soil has a decent chance of staying cooler and more workable.
Water from hard rains that hits unmulched clay soil is likely to cause erosion and soil compaction. Once the soil is compacted, water can run off and be lost. Mulch protects the soil and ideally lets the water filter in and get absorbed where it is needed.
So yeah, near as I can tell from personal experience and certainly in terms of conventional wisdom, mulch is good.
So, what kind of mulch is the best?
There's lots of different opinions on this topic. Many folks seem to make their choice based on aesthetic considerations. As I said above, most people in my region seem to prefer the pine bark or hardwood mulches. It's what you find in abundance at the big box hardware stores and in bulk at plant nurseries.
But I'm hear to draw a line in the ... clay ... and make the case that pine needles (a.k.a. pine straw) is a far superior mulch in nearly every way.
Here are six reasons why you should consider using pine straw mulch on your property:
1) Spreading pine straw mulch is easy - and fast. I've bought more bags of pine bark mulch than I care to remember. I've had it delivered in bulk. I've also used compost as a mulch. Bark and compost mulches are heavy. Typically you have to distribute them by dumping the bag into a wheelbarrow and then using a big spade or shovel to distribute the mulch throughout your bed. It's exhausting and it takes a long time. I once mulched all the beds around my house with 3 cubic yards of mushroom compost. It took maybe 6 hours to distribute. I probably worked 3-4 hours on my own and 2-3 hours with my wife helping. We were both exhausted by the time we finished. And the mulch really wasn't deep enough to be effective. (We should have probably spread twice as much mushroom compost to have gotten the recommended 2-3 inches of uniform coverage.)
By contrast, spreading pine straw mulch is a piece of cake. The mulch is relatively light and it comes in bales. You just carry the bale to the bed where you want to spread the mulch, cut the two cords binding it, then start grabbing handfuls of the pine straw and shaking it where you want to distribute it so that it falls naturally into place.
I didn't have enough pine straw mulch to cover all of my beds, but I probably did half of them (some on my own, some with my wife's help) in about 1 hour -- and at least 10 minutes of that time was removing some dead annuals (Tagetes patula) so that I they wouldn't get in the way of the mulch. I wasn't tired or dirty when I was finished. In fact, it was kind of fun. Extrapolating, I feel I could probably have mulched all the foundation beds with pine straw in less than 2 hours -- a small fraction of the time and effort that it took to spread the mushroom compost mulch.
2) Pine straw mulch seems more eco-friendly. 20 bags of hardwood or pine bark mulch = 20 plastic bags decades (centuries?) to decompose in a landfill. Not to mention all the petroleum used to make those plastic bags.
You can hardwood and pine bark mulches delivered by the cubic yard via dump truck, but there's certainly a fair amount of pollution involved in having dump trucks make those home deliveries.
Sometimes these wood mulches are reportedly made from trees that were clear cut. Apparently this is a big problem with cypress forests in Louisiana, according to an article from the Virginia Native Plant Society.
I think some other wood mulches are made from discarded shipping pallets. I guess that sort of recycling is eco-friendly in a way, but who knows where those shipping containers have been or what was stored on them.
It seems hard (at least through Googling) to get any authoritative information as to whether pallet mulches contain any harmful preservatives or pesticides, but it seems logical to me that they might contain such chemicals since I'm sure the pallet buyers want their pallets to last as long as possible.
As such, I would personally be leery of buying mulch made from discarded pallets. (There's also the issue of the chemical dyes used to color the pallet mulches.) You can read a lot more interesting debates around colored mulch and mulch made from treated lumber on forums like GardenWeb.
(Again, I'm not an expert on this topic. But it seems like the big risk here is inadvertently using a mulch that was made from wood that had been treated with a preservative called Chromated Copper Arsenate (CCA), which the EPA seems to feel rather strongly should not be used around food crops.)
Anyway, to make a long story short (too late), pine straw mulch doesn't have any of those issues. It comes by its coloring naturally. The color will change over time and get a bit darker and redder after a rain, lighter with sunshine and age, but I think it looks beautiful in all its many shades.
From a packaging standpoint, pine straw mulch doesn't typically come in bags, so you don't have to worry about the environmental costs of manufacturing and disposing of those plastic bags.
The ties that bound the pine straw bales I bought were some sort of tough plastic, but I don't see any reason why the bales couldn't be bound with cord made from jute, hemp or some other natural fiber, and I presume that some pine straw bale packagers do bind their product that way.
And then there's the simple fact that you don't need to cut down a tree to make pine straw mulch. Pine trees naturally shed their needles. So all your have to do as I understand it is gather up the needles from underneath the pine trees, pack them into bales and cart them away as mulch.
(I'm not saying there are zero environmental impacts to using pine straw mulch. I've read that there are some concerns about erosion where the pine straw is removed from beneath the pine trees. But it is my understanding that such erosion issues can be minimized with careful management of the pine straw harvesting. There's lots more on the issue of managing stands of pine trees for pine straw harvesting in this About.com article.)
The fact that the bales are so light probably cuts down on the environmental costs of shipping since I believe that weight is a major factor in how much fuel it takes to transport a product. I can tell you that you definitely do not need a heavy duty dump truck to transport a lot of pine straw bales. In fact, where my former car (Honda Insight) was weighed down to the point that it became a Low Rider when I once tried to transport ~20 bags of mushroom compost, I didn't even notice any weight issues at all with 6 pine straw bales in the back of my Toyota Prius. In fact, the bales were so light that they were skittering around in the cargo area when I turned sharp corners.
3. Cost and coverage - According to the Lowe's website, a 2 cubic foot bag of mulch costs between $2 and $5. The Grit website notes that 2 cubic feet of mulch will cover 12 square feet of soil to a depth of about 2 inches. Prefer a 3-inch depth of mulch? That same bag would only cover 8 square feet.
Now by contrast, the pine straw mulch I bought at a local nursery cost me $6.50 per bale. (Lowe's sells bales for $3.99, but I don't know if they're the same size, and anyway I like supporting local nurseries when possible.) Bales vary widely by size - and I didn't measure the dimensions of mine before I spread them - but let's go back to Lowe's which estimates that a bale of pine straw can cover approximately 50 square feet when applied 2-3 inches thick.)
So let's say that you have 1000 square feet of soil to cover. And let's say you're willing to only spread your hardwood mulch 2 inches thick. You'd still need 83 bags (!) of mulch to get that much coverage, which would cost $166 to $415, depending on whether or not you bought the cheapest or most expensive mulch. If you wanted thicker mulch coverage, you'd be looking at 125 bags of mulch ($250 to $625).
By contrast, according to Lowe's estimate, you would only need 20 bales of pine straw, which would only cost $80 (or $130 at the higher nursery price).
Of course, if you're buying a lot of mulch, it probably makes sense financially (and from an eco perspective of not having scores of leftover plastic bags) to buy it by the scoop. Nurseries near me sell cubic yards of pine bark mulch and hardwood mulch for around $35. I saw several sources online saying that 1 cubic yard of mulch would cover about 100 square feet. Another source estimated more generously perhaps that the mulch would cover 160 square feet (perhaps spread more thinly). So you'd be looking at needing anywhere between 6 and 10 cubic yards of mulch for around $210 to $350, plus delivery fee (~$50), for a total cost of $260 to $400.
But don't forget the time and effort of spreading all that mulch. Like I said, spreading just 3 cubic yards wore me out. I'd need 2-3 days just to spread 6-10 cubic yards of mulch. That's with someone helping. On my own, it would probably take me 3-4 days. And I'd also need someplace to dump all that mulch. Even the 3 cubic yards took up a good chunk of the driveway. And it's a real mess trying to shovel the mulch off your driveway without damaging the driveway surface. Of course, you could have the dump truck unload it on your grass, but that would probably carry its own set of challenges and potential damage to the turf, especially if some of the mulch was sitting there for days.
And what if it rains after your mulch was delivered? The day our three cubic yards of mushroom compost was delivered, rain was forecast for the next day. You don't want to trying to shovel soggy mulch. And you don't want it washing away. So that means you're under time pressure to work like mad to get the mulch (or compost) distributed before the rains arrive. (Well, unless you have a really big tarp with which to cover the mulch. We had a tarp, but it wasn't big enough. And anyway, we were using it under the mushroom compost to try to protect the driveway from scratches or other damage as we shoveled up the mulch.)
So any way you look at it, I'd say the pine straw mulch is significantly less expensive (say from 50% to 85% less expensive). Much easier to spread on your beds. Much faster to spread on your beds. Incredibly easy to store inside your garage (or shed, or car) if rains threaten. Really no contest for me on this point.
4) Pine straw looks better. I admit this is purely subjective, but I think the pine straw mulch looks much nicer than the bark and wood mulches. The big bark pieces look messy to me, can be painful to dig through and take forever to decompose. The pine fines (finely ground pine bark) disappears really quickly and soon looks (and acts) just like bare dirt. It gets dusty and dry in the summer. It doesn't seem to suppress weeds one bit.
By contrast, the pine straw looks soft and billowy, like a wave or a cloud. It looks natural. I always loved the way that the pine needles looked beneath a big pine tree on our property where I grew up in Pennsylvania. So maybe it's pure nostalgia, but it's just a joyful thing for me to look at the pine needle mulch. And I think the plants look better against the mulch - it provides a uniform background against which they really pop and seem brighter, greener and more vibrant.
5) Pine straw is easy to rearrange. This is important for me because I plan to plant more perennials in the beds and even sow some annual flower seeds. So I need to be able to push back mulch from certain parts of the bed, sow the seeds or add a new perennial, then move the mulch back into place later on. Just as the pine straw mulch is easy to initially distribute, it seems incredibly easy to rearrange as needed.
6) And yet, Pine straw stays in place when necessary. A couple of my mulched beds are near the driveway and a paved pathway. We get a lot of heavy rains here and often I'd find hardwood mulch scattered onto the driveway after a big rain. It's still only been a few days since I put down the pine strawn mulch, but we had some significant rain last night and the straw doesn't seem to have gone anywhere. In fact, the rain seems to help the pine straw sort of 'lock' into place.
I have to admit, this was probably the one major concern of mine. But it was alleviated when I saw that the professional landscaper we hired to redo our hilly front yard suggested using pine straw around the trees and perennials. We had some really strong winds and rains after he worked on the landscape and the mulch seemed to hold up like a champ. So I figured it would do even better on the flatter landscape beds near to the house and so far it has performed up to expectations.
Update - Well, unfortunately some of the new pine straw mulch I put down did blow around a little, especially on one of the beds that was most exposed. We had sustained winds last night of 25 mph with gusts of 35 and we're on a little hilltop, so... Other beds that are less exposed to the wind were less affected. Also, the pine straw needles moved most on the bed that had the least mulch. One commentator on GardenWeb says that spreading pine needle mulch thickly helps keep it in place. (I guess maybe all the needles interlock?) Anyway, most of the pine straw still seems to be there, just shifted a bit onto some of the grass. So I'll push/rake it back into place. According to this site, it seems like maybe I should have watered the pine straw after I spread it to settle it into place. The pine straw mulch put down professionally a month ago still seems to have stayed in place nicely. If anyone has any advice or experience with preventing pine straw mulch from going airborne, I'd appreciate your insights.
There's some more good advice here from a professional landscaper on the best way to install pine straw mulch.
Despite appearances to the contrary, I'm not saying pine straw mulch is perfect. Obviously, I have not had it long enough to know how it will perform over time. Will it do a good job of suppressing weeds? The bar is pretty low here since the (admittedly somewhat thin levels of) bark mulches did not seem to suppress weeds at all.
Will the pine straw decompose so quickly that it becomes cost prohibitive to keep the beds properly mulched? One nursery worker who unfortunately convinced me not to buy pine straw mulch a year ago (probably because his nursery didn't carry it) told me that pine straw mulch decomposed too quickly to be useful. But then he told me the mulch would blow and wash away, which it clearly has not. And one of our neighbors (from the Carolinas, where pine straw mulch is apparently very common) has had pine straw mulch installed for a year now and seem to have excellent weed suppression and the mulch seems to have persisted just fine.
I anticipate that I'll need to add some additional pine straw mulch - perhaps another six bales - to get good coverage over the rest of my beds and deepen the mulch a little on the beds I've already mulched. After that, I'm thinking I really won't mind freshening up and adding to the mulch ever year or two with another six or so bales. Really doesn't seem unreasonable to me.
The one concern I have - which sounded sensible to me when my landscaper mentioned it - is that small perennials and groundcovers can get lost in a pine straw mulch. I can see how that could be an issue, but it doesn't seem like much of a hardship to just keep the pine straw pulled back from those smaller plants. And if the pine straw covers up some of the really low groundcovers - like Blue Star Creeper - well that means that theoretically it's also smothering a lot of low-growing weeds. And that's a trade-off I'm willing to make, considering I mainly grew the Blue Star Creeper to outcompete the weeds. Anyway, I don't think that the larger perennials - and by large, I mean even those that are 4-6 inches high like Sweet Woodruff or Rozanne Perennial Geranium - will have any trouble holding their own against the pine straw mulch. Time will tell.
Other issues? I'm a little concerned that pine straw mulch could be a welcoming environment for the pygmy rattlesnake. One commentator on GardenWeb suggested stomping or hitting the ground with a rake to warn off snakes and give them time to slither off. I suppose I should also invest in some gardening boots that cover my lower legs.
I'm also still interested in using a variety of ground covers instead of or in addition to mulch, but ground covers take time to fill in, so I think the mulch will be very welcome at least in the short-term.
Oh and some people are either concerned or excited about the supposed ability of pine needles to add a bit of acidity to the soil. Not sure whether this idea really holds water. In any case, I do have some acid-loving plants like camellias, azaleas and a gardenia in the front bed who will probably be very happy if the pine straw mulch acidifies the soil even a little bit.
There are many other mulch options that I did not touch on above, most of which I've investigated and then discarded for one reason or another. I'll run through them very briefly here:
- Stone and gravel mulches -- Many people who have gone this route express dismay and regret in online message boards. Apparently, dust and dirt blows on top of the stone and gravel, creating a growing medium in which weeds can sprout. People also seem to think it's hard to add plants (bushes, perennials, etc.) into the stone mulches. Plus of course, the stones don't add any organic matter to the soil.
- Leaf mulch - Well, I don't have nearly enough leaves to do this, for one thing. I did try to rake leaves from my crape myrtles and maple into my garden beds, but those will decompose so quickly that they won't provide weed suppression benefits. Plus leaves have a tendency to blow away. And then there are leaves like oak leaves that take forever to decompose. I've got some sitting in a small bed by the mailbox that are still there from last autumn, so maybe 15 months now. And they don't look like they're about to decompose anytime soon. Don't look that attractive either, to my eyes. So I'm all for leaf mulch on occasion and in the right place or added to a compost pile perhaps, but I don't think it's a realistic long-term mulch solution for many people.
- Wheat straw mulch - Worried about the straw itself sprouting, which would sort of go against the whole weed suppression thing. Plus I'm not sure how I would feel about this aesthetically, although I could see it working in a veggie garden.
- Cocoa shell mulch - Interesting. Exotic. Might smell like chocolate, which I think sounds intriguing. But the smell apparently fades quickly - which happened with some cedar mulch I spread a while ago - and the mulch is supposedly so light and fluffy that it blows and washes away easily. (Although they said that about pine needles too.) And then there's the fact that cocoa mulch could be hazardous to canines. Oh yeah, and the fact that I've never seen cocoa shell mulch ever in any local nursery or garden supply store. And wouldn't the shells need to be shipped in from a tropical climate where cocoa beans are grown. That doesn't sound very eco. Unless the beans were shipped to the local area anyway for processing in which case I guess using the shells for mulch would just be creative reuse of something that would otherwise be treated as a waste product.
- Rubber mulch - Does not improve the soil and um, I think it's mainly made from used tires. Ugh. Don't want that anywhere near my veggies and certainly wouldn't want children playing on it.
- Cover crop mulch - One idea that I'd like to try in the long term would be growing a cover crop like Buckwheat or Alfalfa in the garden and then taking the chopped or winterkilled tops and trying to use them as a mulch. But I'm guessing they would decompose too fast to use as a real mulch and that they would function better as a so-called green manure. Incidentally, buckwheat hulls are an interesting mulch option, but as Cornell notes, they're typically very expensive compared to other mulches and prone to blowing. So I guess probably only a good option for millionaires with good windbreaks! ;-) But I like the idea of growing your own mulch rather than relying on store-bought mulch. Even pine straw after all has to be gathered, baled and shipped. Homegrown mulch certainly sounds more eco-friendly. Here's one guy who took this path-less-traveled and tried to grow his own mulch using oats.
Of course, planting pine trees on my own property - or finding a neighbor looking with pine trees looking to get rid of excess needles - might also be a good sustainable, local and cost-effective approach to mulching...
What do you think about pine straw mulch? Has this post convinced you to give it a try? Or are you already a pine straw mulcher? Or do you prefer to use groundcovers vs. mulch?
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