Mulch- Not Just A Pretty Face

Everyone knows mulch makes a landscape bed “prettier” but did you know it’s functional as well? Mulch is usually the last detail when designing a bed, or installing a landscape bed as well; not because it’s not important but because you’re saving the best for last! Mulch is the final detail that creates the aesthetics of your landscape as well as the finishing touch to keep your landscape thriving. Here’s why:

Throwing Benefits.

The very first benefit that comes to mind is that it helps keeps your soil retain moisture and nourish your plants. You can see a huge difference between a well mulched beds and a non-mulched bed during the summer here in Florida. I generally recommend around 3 inches of mulch to adequately cover soil and act as a moisture buffer. You want as much of your irrigation to stay in your soil with access to your plants rather than getting evaporated into the air. If you pay for you water, this is even more important! This is also why we recommend watering in the early morning or around dusk so water has a chance to work its way into the soil when temperatures are at their lowest during daylight hours.

Although we don’t have true seasons in Florida, we do have the occasional freeze night during January or February. Mulch is important for insulating your plant’s roots. It can help keep them cool in the summer but more importantly, it can help keep them warm during freezes. This is especially important for plants who go dormant during winter and need protecting from the cold.

Although, the most important and best consumer benefit of mulch would have to be that it keeps out the weeds. This only applies when you put it thick enough. Often times, people use mulch as an aesthetic feature and spread mulch thin, just enough to look pretty from the road or walkway, but then they are constantly fighting weeds! If you put your mulch thick enough the first time, you wont have to fight with weeds (as much) and you wont have to remulch as often!

One of the most overlooked long term benefits for using mulch is that as mulch breaks down, it provides organic matter to your soil encouraging vital microbes and earthworms.

Throwing in the Wrong.

There are incorrect ways of “throwing” mulch.

First, make sure you lay it thick enough! I cannot stress this enough. 3″ is ideal for keeping in moisture and keeping weeds out. With that being said, you don’t want your mulch too thick. It’s a waste of money and can lead to other problems such as fungus and mold growing in piles of damp mulch, used as housing for other creatures like rates, mice, cockroaches, snakes, etc. When mulching too thick it may also encourage upward root growth instead of downward because your mulch will hold more moisture than your soil…

When you throw your mulch out, you don’t want it touching the stem or trunk of the plant. Keeping mulch up against a root stem can cause rotting (remember, mulch=moisture retention). You don’t need a huge space between the stem and mulch but enough for adequate air flow. This includes volcanoing around trees (shown on the left below). You should create a donut with much to keep water in (shown right below).

You do not want to go light on the edges and extra thick in the middle of your bed. Your landscape bed should be mounded as necessary before planting and mulching. Mulch is not meant to add depth to your plant bed. Lighter mulching on edges will encourage grass and weeds to impede on your landscaping. You want all of your mulch to be relatively the same thickness.

So Many Choices.

With mulch, there are many choices from color to material to size used. I cannot say that there is one that is better over all else but each has their pros and cons. I have my favorites and least favorites which I will list but each has a place in some landscape based on budget, theming, maintenance needs, plant needs, and other factors.

Pine bark (left): My favorite mulch option because it’s affordable and looks nice. It does fade over time but decomposition is slower. Pine bark is easy to get a hold of, in bags or in bulk, and easy to work with. No need to worry about splinters here! It comes in different sizes from mini to large nuggets and I’ve recently seen red pine bark for sale as well. Cons to pine bark is that it easily floats when water puddles so make sure you have an edging to keep mulch in place (which I recommend with most mulches). Large nuggets are not as effective in keeping moisture in the soil as small nuggets so opt for the smaller size. Over time, as pine bark breaks down, it can make soil more acidic, changing the pH of your soil. You can monitor this with soil testing kits and rotating your choice of mulch.

Red Mulch (right): The cheapest mulch available and often on special at box stores, this mulch is a shredded pine mulch. It does has the tendency to float like pine bark because it is a soft wood. The red is a dye which will fade, as all dyes do. Because it is a soft shredded wood, it will breakdown faster than hardwoods or even its cousins, pine bark and pine straw. The price and color make this mulch attractive. It’s a basic mulch but it does add nutrients to the soil as it decomposes.

Cypress mulch (left): Cypress mulch is one of the least expensive mulches and is made from Bald Cypress and Pond Cypress trees. It comes in chips and shredded but shredded is most commonly seen. It does not change the pH of your soil as it decomposes, but adds nutrients all the same. It generally comes in a blonde color and fades to a soft weathered gray color, which some people like. It is more dense than pine bark so it does not float off. The University of Florida recommends that you do not use Cypress mulch because trees are being harvested out of Florida’s wetlands faster than they can regrow, which will have a major impact on Florida’s wetland environment in the future.

Hardwood Mulch (right): This hardwood mulch is often colored, seen in red, black, and brown. This mulch is often a combination of shredded hardwoods such as oak and maple. It can compact over time and more suited for beds on an incline or wet climate locations. A major downfall to these mulches is the dye fades almost instantly. Many people buy this mulch for the color. If this mulch is best suited for your area, I recommend purchasing the brown so it lightens up to a lighter, gray brown versus the red turning pink and the black turning gray. The cost of hardwoods is often higher than cypress or pine bark but still less than other premium mulches.

Rubber Mulch (left): This is the least of my mulch recommendations. It will fade however it doesn’t breakdown, meaning your soil will not receive the organic matter from decomposing mulch. It does come in different colors and textures (shredded or nuggets) but is very expensive. It is a way to recycle old tires and does not tend to float or blow away like softwood mulches. It has been noted that this mulch can last for up to 10 years. It doesn’t attract insects like carpenter ants or termites like wood based mulches can potentially do but it cannot be tilled into the soil and must eventually be removed. This type of mulch is mostly used on playgrounds. It can also be sanitized, an added benefit making it kid friendly.

Melaleuca Mulch (right): Melaleuca is an invasive tree that is slowly taking over and killing Florida natives. This is a great option if you want to “go green” and help the Florida native environment. Of all organic wood mulches, it is most resistant to termites. Increased demand has called for increased removal of such trees from our wetlands. It comes in a golden color and fades to often a light brown weathered color. This is a relatively new mulch option with increasing demand.

Pine Straw (left): Pine straw is a by-product of the pine lumber industry from plantations grown specifically for lumber or can be harvested from plantations yearly when pine trees naturally shed their needles, all without cutting down a single tree. It is a renewable mulch sold in bales. It is unique in that it has a natural fine texture to it, and often seen in native gardens. As pine straw breaks down, it can make soil more acidic (like pine bark) but this is ideal for acid soil loving plants like azaleas, camellias, and roses. It does breakdown and returns organic matter to the soil. Pine needles often break down slower so remulching is not necessary as frequently. One con is that it can look messy when leaves or twigs fall into the mulch. They cannot be simply raked out. Another con is the cost of pine straw. It is often sold by the bale and is more expensive however, one bale covers a larger area than a 2 cu. ft. bag of wood mulch.

Eucalyptus Mulch (right): Eucalyptus is often grown on plantations specifically for mulch purposes. There are concerns of its toxicity but the toxicity is relatively short lived and this mulch can be a short term natural insect repellant and weed suppressant. After the allelochemicals are leached from the mulch, they are the same as any wood chip mulches. It is not shown that the allelochemicals leached suppress plant growth, however, I would recommend rotating this mulch with other mulches to alleviate any build up of allelochemicals in your soil over a long period of time. Eucalyptus mulch is golden in color, generally shredded, and fades to a weathered gray color over time. I have seen eucalyptus available in red color as well. It is lower in cost compared to hardwood mulches.

Stone/ Rock/ Gravel (left): Stone, rock, and gravel lasts a long time because it does not break down; however, weeds can often still grow through the cracks and aggregates. Because it does not break down, it doesn’t provide any organic matter to the soil. It must eventually be removed because it cannot be tilled into the soil. It is often a pain to remove. It can get dirty and grow mold or mildews from moisture build up. Rock, gravel, or stone may be recommended in few places for functionality purposes (like down spouts, areas without gutters or prone to water build up) but an easy application now will be a painstaking labor to remove later. However, there is a tons of options of sizes, colors, and types ranging in all sorts of prices. Some include, egg rock, pea gravel, granite, quartz, Mexican beach pebbles, volcano rock, and more. They’re sold mainly in bags of 0.25 cubic feet. I usually only recommend rock or gravel for pathways, down spouts, or main focal areas that need to be emphasized. Rock, gravel, and stone are also commonly used in themed gardens like oriental or Asian gardens featuring statues, potted plants, and architecture.

Organic/ Household Options: I have not personally used these but they are ideas that could get the job done, although I’m not sure how your neighbors would take some of these from an aesthetics stand point:

grass clipping
newspaper, shredded or full sheets
old clothing
leaves

Note that thin material like grass clippings or leaves may decompose quickly and require remulching often. Grass clippings can also have weed seeds that may germinate as well, despite the “mulch”.

Weed Barriers, The Biggest Landscape Lie.

Although mulch serves as a weed barrier, some of those pesky weeds still manage to germinate. For this reason, people, as we generally do, started looking for a quick fix to weed problems without having to resort to chemicals or manual labor. Weed fabric is the biggest lie any box store personnel can sell you. After just covering most of the mulches above, you should know now a major benefit is it’s ability to break down and return organic compost to the soil. How can it do so when there’s a protective layer of fabric or plastic under the mulch? Often times I meet with clients who ask for weed fabric. I highly recommend against it because of their mulch choice (usually pine bark or “whatever is cheapest”). The only mulches you should use weed fabric with are rubber mulch, rock, gravel, stone, or other mulches that DO NOT breakdown. When your mulch breaks down on top of your weed fabric, you’re basically creating the perfect environment for your weeds to grow.

There’s been a few residents that I have renovated their landscape beds and found several layers of landscape fabric. They continually laid it down before taking up the old. Landscape fabric is okay if you replace the mulch and fabric through out the year but you’re still missing out on the decomposing factor of mulch adding nutrients to your soil.

From an installer’s stand point, it’s also a pain to lay making the install process that much longer. Before you place the plants, you lay out the fabric, stapling down the edges. Then once you determine where each plant is to be planted, you have to cut out holes before you can dig. It generally makes installs 2-3x as long for little to no benefits.

A Better Weed Solution.

Please note, Homegrown Landscapes stands behind this practice but does not offer this service.

I don’t like the look of whole newspaper as a mulch; however, instead of using landscape fabric, using newspaper under your mulch can help deter weeds. Newspaper naturally breaks down and decomposes. This is the best recycling practice I have used to date.

When we were ready to install our landscape in front of our house, we decided to try a new recycling, weed barrier practice I heard about and you know what? I am in love and I am a believer.

We tilled, leveled, and planted our plants. Then before mulching, we went through and layered newspaper around our plants. It took forever, and we had to save up newspaper for weeks (which is why Homegrown does not offer this service). We put at least 3 layers of newspaper over the entire area, wetting the paper down as we went to keep it in place. We then mulched over and you know, that was in 2013. My weed problems consist primarily in areas where I recently removed plants and soil was exposed. We will continue to do this when we remulch to keep another several years weed free!

Getting Edgy.

Many people ask me about edging and it all depends on the amount of maintenance you want to keep. Edging helps keep your mulch in your beds while keeping grass and weeds out and therefore goes hand in hand with our discussion of mulches.

You do not HAVE to use an edge. If you do not, I recommend making a slight trench along your bed for mulch to settle in instead of washing into your grass. If you do not edge or have an edger (which is the preferred method), I also recommend “edging” with roundup to kill grass and weeds trying to impede in your landscape bed. Use a thin tip spray nozzle to you don’t have a huge dead line lining your beds but this is one way to maintain your bed lines.

There’s the classic black plastic edging. Although this is sufficient, it can be difficult to maintain. It is easily pulled up by lawnmowers or broken by edgers. It can get pushed down, stomped on, broken, pulled up, moved, etc.The good news is, it is cheap to replace and easy to find.

Pavers are my preferred method of edging, although it can become expensive depending on the size of your bed. I recommend, if doing your own pavers, to trench where your pavers are going so they are held in place on both sides by soil. There is also edging similar to black edging for this purpose, although I haven’t used it.Pavers are often tall enough to keep mulch (at 3″) contained and the different textures, colors, and sizes make them a good match for almost any landscape. One downfall is that the more specified a paver is, the more likely it is to be discontinued down the road. I recommend staying with a really general paver so should you need replacements or when adding beds, you can easily find your matching pavers. Other options with paver are to concrete behind them to make sure they stay in place. However, this is only good if you plan on leaving your landscape that shape for a long period of time. For instance, our landscape bed has been the same for 2 years, however, we are wanting to extend the bed. Because we did not concrete the pavers, we can easily pick them up and move them. But I often find myself fixing the pavers on the ends which tend to move. It all depends on your preference.

There is also curb edging. This is solid concrete edging in specified shapes, usually made to look like bricks or pavers. This is a more expensive option however, it is good as a set it and forget it option. This usually cannot be done DIY but requires correct equipment. It is available in different patterns and colors.

Remulching Timeline.

Remulching your landscape is really up to you. When I was at Busch Gardens, we remulched beds every 2 weeks due to litter build up of leaves, trash, etc. However, in a residential environment, remulching depends on the owner preferences, and the mulch used. You should ALWAYS remulch when you see that your mulch is breaking down and weeds are popping up. This isn’t on a timeline but very dependent on the mulch you selected, and your environment you live in. For instance, my landscape beds are on the north side of my house (less sun), we have gutters (less water gushing through my beds), and we have drip irrigation (no overhead watering) so my mulch has lasted about 2 years. It’s faded and there are remnants of hedge cuttings but that’s okay with me. Often times, many people want mulch traded out as soon as it fades. That is not necessary but, again, dependent on the owner.

I recommend when you are ready to remulch, remove the solid pieces of mulch with a rake, leaving the small broken down material. If possible, till it in with the soil (if you are renovating the bed). It is important to remove the old pieces of mulch so you start with a level bed. Often times, people throw mulch over old mulch. Once may not hurt but over time you get so much build up of organic material because it hasn’t been tilled into the soil. When we renovate a bed, we often end up taking out a lot of dirt trying to level or slightly mound the bed opposed to having a mountain of a bed. Your landscape beds do not need to be more than 6″ above your grass level, or you may have mulch run off, no matter what mulch you use.

When you have a severe weed problem, mold/ mildew problem, disease problem, or insect problem, I highly suggest remulching immediately. Often times, as mulch breaks down and weeds go to seed (which is why its important that you pull them as soon as you see them), your mulch can be harboring weed seeds, in which case, you may never catch up. Mulch once succumbed to pests or diseases needs to be discarded and relaid. I would allow a “drying” time between mulching, leaving your beds without mulch for a day or so. Often times these pests or diseases are attracted to the moisture mulch holds. This will also give you a chance to adequately treat for the problem if necessary. There after, you may want to reconsider how often you water (reducing the amount of time watering or the number of days) or making sure you mulch is no more than 3″ thick.

What Works For You?

Your mulch (and edging) choice really boils down to your budget and how much maintenance you want as well as what look you are going for. But if you don’t lay your mulch correctly, you may be wasting your money, and creating more problems for your landscape.

What to take away:

mulch has many benefits for your landscape
mulch should be roughly 3″ thick and not touching plant stems/ trunks
do not lay weed fabric under mulches that break down, use newspaper if another weed barrier is desired
maintain your edge to keep mulch in and weeds out
remulch according to your needs and preferences

If you have any questions about mulching or are ready for your beds to be remulched, call Homegrown Landscapes at 813-763-5082 for a free consultation.

Other Resources for additional information:

https://www.arborday.org/trees/tips/mulching.cfm

http://www.gardeningchannel.com/importance-of-mulch/

http://homeguides.sfgate.com/benefits-cypress-mulch-44920.html

http://www.thisoldhouse.com/toh/photos/0,,1209283,00.html

http://www.angieslist.com/articles/what-are-pros-and-cons-rubber-mulch.htm

http://pasco.ifas.ufl.edu/gardening/mulches.shtml

http://homeguides.sfgate.com/eucalyptus-mulch-toxic-plants-57519.html

http://homeguides.sfgate.com/benefits-using-pine-straw-mulch-46745.html