Natural bark mulch
There have been a lot of questions about the use of colored mulches in the landscapes. Many individuals are concerned about the possibility of negative environmental impact from the dyes used on wood chips and pine straw. According to the Center for Agriculture, Food and the Environment (https://ag.umass.edu) the primary concern with colored landscape mulches is not the dyes used for coloring. Rather, it is about the sources of wood chips and the possibility of contamination with toxic substances.
The dyes used in coloring wood mulch are primarily of two types: carbon-based dyes and iron oxide based dyes. Iron oxide, the most commonly used dye, is simply a compound of iron and oxygen. As the compound oxidizes, iron is released to the soil but is not considered to be toxic. Dyes that are not absorbed by or adsorbed to the wood would come off with contact, especially if the mulch is wet. There are also some carbon-based dyes used on mulch. These carbon-based colorants are similar to those used in ink and cosmetics. Other dyes for mulch are vegetable-based and therefore organic. At this time, there is no evidence that the dyes used to color wood chip mulch are toxic.
Most of the wood used for making colored mulch comes from recycled wood, i.e. wood scraps, wood pallets, and wood reclaimed from construction and demolition (C&D) waste. Besides the benefits of recycling waste wood materials, the reason why these wood materials are used for colored mulches is that they are very dry and readily absorb or adsorb coloring agents.
Unfortunately, some of the recycled waste wood used for making landscape mulch products is contaminated with various chemicals, such as creosote and CCA (chromated copper arsenate). CCA is the chemical that was used in the manufacturing of pressure-treated wood.
Even though arsenic-based wood preservatives were banned in 2003, there are still plenty of CCA preserved wood being re-purposed. Sometimes wood pallets that have been used in the transport of chemical agents can become contaminated by spills of these chemicals. CCA and other toxic chemicals have been found to be contaminating soil where colored mulch made from these wood products have been applied. CCA treated wood can kill beneficial soil bacteria, beneficial insects, earthworms and young plants. It can also be harmful to people spreading this mulch and animals who dig in it.
Additionally, dyed mulches break down much slower than natural mulches. The greatest advantage to using them is to reduce the expense and time required to replenish the mulch. When wood breaks down, it requires nitrogen to do so. Colored mulch can actually rob the plants of the nitrogen they need to survive. Natural mulches retain moisture and add organic material back to the soil enabling the plants to better utilize nitrogen. Avoiding the use of colored mulches reduces the risk of contamination better than any other practices. Colored pine straw may be an alternative.
It should not be assumed that all colored mulches are contaminated. However, anyone planning to use colored mulch should become familiar with the supplier and the source of the wood used in making it. If C&D waste wood is used, it should be a red flag that there is a possibility of CCA contaminated mulch.
Certified Mulch Label
If you wish to improve the chances that the dyed mulch that you are buying is safe for humans to handle look for the MSC Certification Logo on the packaging. MSC stands for Mulch and Soil Council, whose responsibility is to certify that a mulch or soil product is free of CCA-treated wood. According to MSC’s Product Certification program, “Certified mulches and soils can be found at major retailers and garden centers across the country.” If you have concerns after contacting the supplier about the source of the wood used, contact a private environmental testing lab in your area.
While reading packaging, check the source of the product. If the supplier is a land management company rather than a processing mill it may be that mature trees are being removed and shredded. These mulches are sold as “long-lasting”, “no-float” products. They have the appearance of pine straw, but are actually finely shredded cypress from the heart of trees. These are coming from properties where the bald and white cypress trees are harvested for mulch. You can tell that it isn’t pine straw because the mulch pieces lack pine needle structures such as the fascicles and a revolute shape. While the use of these products is not contaminating, it is still depleting the environment. Mulches that are natural by-products are the most Eco-friendly.
Storm debris turned into holiday cheer in Bayou George. Photo: J_McConnell, UF/IFAS
By the time this article publishes, we will be more than 70 days since Hurricane Michael toppled or damaged an incredible number of trees in the Panhandle. Enormous piles of once stately shade trees line the streets in neighborhoods and business districts in. The cleanup efforts have been phenomenal, over 4 million cubic yards of storm debris picked up in Bay County to date, but there is still a long way to go in the recovery process.
So, as gardeners, how can you help our community get back on track amidst your own struggles to recover? A few Florida Friendly Landscaping™ Principles come to mind.
- #1 Right Plant, Right Place – as you rebuild your landscapes, make sure to choose the appropriate plant for the location. Consider mature size and give those plants space to thrive!
- #4 Mulch – do you have bare ground that will eventually become landscape beds or turf but no resources or time to replant yet? Consider mulching the area to keep soil from eroding and to help improve soil though decomposition of natural products. Hint – see Recycling for free sources!
- Mulch tips https://sfyl.ifas.ufl.edu/media/MulchBrochure.pdf
- keep mulch 12 inches from tree trunks
- recommended depth in beds or under dripline of tree canopy (excluding within 12” of trunk) is 2-3 inches
- leave an 18-24 inch buffer around building foundations mulch free to reduce conducive termite conditions
Dress up stumps with plants and whimsical designs. Photo: D_VanderMeer, UF/IFAS Master Gardener
#7 Recycle – driving around town I have seen some really creative uses for stumps, trunks, and branches that homeowners have constructed and messages of hope that bring a smile to my face. Another method of recycling is to use the chipped vegetative debris as mulch, either available as “utility mulch” by cities and counties or you may have some in your own yard right now.
- Utility mulch does come with some words of caution because there is an increased risk of introducing weeds to your landscape with untreated storm debris. However, if you need mulch for pathways or planting beds you will be helping your community’s cleanup effort by reducing waste accumulation. Just watch for “volunteer” plants and manage as needed.
In Bay County, there are 4 locations where you can load and haul off your own utility mulch from storm debris
- Under the Oaks Park – 5843 E. U.S. 98, Panama City, FL 32404
- G. Harder’s Park – 8110 John Pitts Rd., Panama City, FL 32401
- Chapman Park – 2526 Rollins Ave., Bayou George, FL 32404
- Laird Park – 6310 Laird Park Rd., Panama City, FL 3240
For sources in your county, check with your Solid Waste Department for utility mulch availability.
Just when you think your battle against weeds is over for the summer, cooler nighttime temperatures and shorter days spark the beginning of a new crop of your least favorite plants. The question of many homeowners is how did all the weeds get to my landscape?
There are many ways that weeds make it to the landscape. They can be brought in with new soil, mulch, container plants, dropped by birds, delivered on the fur of animals, carried by wind, or on the deck of a lawn mower. If that is not enough to depress you than also realize that regardless of outside sources of weeds, your landscape already has plenty onsite that you don’t even know about.
The deck of a lawn mower can collect plant debris, including seeds, that are spread through the landscape. Photo by Beth Bolles, UF IFAS Extension Escambia County.
In the soil, there is a large number of weed seeds ready to germinate when the conditions are just right. Understanding how your common landscape practices can encourage or discourage the germination of these seeds, can help you begin to manage some weed infestations.
Many of the seeds of common annual weeds are very small. They require exposure to sunlight in addition to the proper temperatures and moisture to germinate. Sunlight is critical though and seeds will not germinate without adequate sunlight. If the small seeds are deep in the soil, you will probably never know they are there. When you turn soil or disturb soil such as when installing plants, you bring the small seeds close to the surface and closer to light. They can then be stimulated to germinate. The next thing you know is that you have an area covered in weed seedlings.
What does this mean for your gardening practices? Try your best to block sunlight from hitting exposed soil. You can do this by keeping a healthy turf, free of thinning spaces. A 2-3 inch layer of mulch in plant beds and vegetable gardens will reduce weed seed germination. Finally when you are installing plants in an established bed, try not to mix soil with surrounding mulch. Seeds will easily germinate within the mulch if it becomes mixed with soil.
It is inevitable that your landscape will have some weeds but a few easy gardening practices can reduce some of your weed frustrations.
Billions of leaves blanket the fall landscape and are bagged by hundreds of homeowners to be placed curbside for local trash pick-up.
Many of these leaves could be easily turned into valuable mulch or compost.
Why do all those fall leaves end up in bags to be discarded?
It’s probably because the homeowner is overwhelmed by the volume. For instance, one resident reported raking more than 100 large bags of leaves from his half-acre property. One large oak tree can contain over 250,000 leaves!
Bagged and discarded leaves could become a quality mulch or could be composted.
Homeowners have tools for reducing 100 bags of leaves to 10 in their own backyards.
Shredding and composting can reduce leaf volume by 90 percent and provides a manageable quantity of valuable mulch and an excellent organic source for composting and converting into rich humus to improve garden soil.
Shredded leaves stay seated better on the landscape than whole leaves. They also do a better job of holding moisture in the soil and don’t mat down like whole leaves.
But how do you shred leaves if you don’t have a costly leaf shredder?
All you need is a lawn mower, a little extra time and a concern for the environment. Just put the leaves on the lawn in rows around three feet wide and two feet deep.
Then, with the lawn mower at the highest wheel setting, run over the pile. If the mower has a bag attachment, collecting shredded leaves is a neat and easy task.
Without a bag, the easiest way to collect them is to put a 9-by-12-foot drop cloth parallel to the row of leaves. Then, by running the mower in one direction so the leaves are discharged onto the cloth, cleanup is easier.
Throw the shredded leaves in the compost pile to cut the volume by another 50 percent.
Shredded leaves will shrink within a week and compost faster than whole leaves.
To compost dry leaves, add water, a little garden soil and a cup of garden fertilizer.
For more information on gardening and landscaping, contact the UF/IFAS Extension Office in your County.
Do you have a bare spot that you would like to see go away? How about a problem getting something to grow in a particular area? I’m not talking about that receding hairline or bald spot, I’m talking about your lawns and gardens. Many residents have these problems, whether it is too much shade under our beautiful oaks, that stubborn orange clay, or that hot, dry sand. Often times, the best remedy for these situations is to use mulch. Mulch is a versatile tool in the home landscape that provides many benefits while adding aesthetic beauty.
Some of the benefits of using mulch in your landscape include retaining soil moisture, reducing the amount of weeds, insulating the soil (keeps it warm during cold months and cool during the warm season), improving soil health through decomposition, and protecting plants from mower and/or trimmer damage. In addition, mulch can help protect the quality of local lakes and streams by reducing soil erosion and stormwater runoff. Therefore, not only can it improve your yard, but it can also help minimize impacts to our precious natural resources.
When purchasing mulch, there are many options available. Local lawn and garden shops offer many different types of mulch based on their origin (type of wood the mulch comes from), texture (shredded vs. nuggets), color, and, of course, cost. When considering these options, here is some information to help you choose:
- Origin. Cypress mulch comes from the harvesting of natural cypress wetlands and it not recommended by the University of Florida Florida-friendly Landscaping Program. Pine bark mulch is produced from the paper/pulp industry as a marketable byproduct. Pine needle mulch is harvested from pine tree farms as the trees mature to harvestable size.
- Plant Needs. Pine mulch (either bark or needles) can lower the pH of your soils as it breaks down over time. This is great for acid-loving plants such as azaleas, gardenias, and blueberries, but may affect species that require a high pH.
- Texture. The coarser the texture, the longer the mulch will last. Finely shredded mulches breakdown quicker than coarse mulches, such as bark nuggets. As the mulch breaks down, it adds organic content to your soil, thus improving soil health.
If you want to save money, you can often contact local tree trimming companies for their hard day’s work. As they trim or remove trees, the smaller material is shredded into mulch and they are often willing to drop it off in your yard instead of paying for its disposal. It is best to allow this freshly shredded mulch to cure for some time before placing it in your garden beds since freshly shredded mulch can temporarily reduce the availability of nitrogen in the soil.
When using free mulch options, be aware that weed seeds may be present.
Be sure to apply the mulch in a two to three inch layer in your landscape beds or around trees and shrubs. It’s not a bad idea to aerate any old mulch already present to prevent matting or compaction. This can be done with a rake or pitchfork.
So cover up that soil to improve the look and fertility of your landscapes and to reduce erosion and stormwater runoff. If you have any questions about mulch, more information is available at the Florida-Friendly Landscaping website: http://fyn.ifas.ufl.edu.