Dealing With Spring Showers & Color-Enriched Mulch
Spring is the time of year when everything seems to come back to life, including the mulching season. Unfortunately, also accompanying spring is seasonably wet weather. This presents some challenges for color-enriched products. Understanding the coloring process and some simple dos and don’ts will help provide you with a more rewarding experience. Noted below is a brief overview of how the coloring process works and options on renewing “washed” product.
The Coloring Process
To understand how colored mulch may experience product “washing” on occasion it is necessary to have a general understanding of how the color-enriching process works. The colorant is dispersed in a water-based solution in the production process. Water is the carrier that enables the colorant to coat the wood fiber surface. While water is of great value to help evenly coat the wood fiber with rich color, it also acts as a carrier between the wood and colorant particles until fully dried. When the mulch is completely dry the colorant particles bond to the wood and cannot be broken just by adding additional water, such as rain or a sprinkler system. The bond needs time to form between the colorant particle and the wood fiber. This is referred to as critical drying time.
There is no steadfast rule on what is the required critical drying time. Base fiber moisture content, production inventory time and weather all contribute to the variability, yielding a wide range in possible drying time requirements. Experience tells us the range of 24-72 hours is a comfortable window. The timeframe is based on when the product is installed not produced.
Installation Dos and Don’ts
- Dump bulk mulch onto a tarp to prevent discoloration to the ground or driveway surface. If a tarp is not available we recommend wetting down the driveway or lawn before dumping the mulch and washing the surface off with soap and water after applying the mulch if there is any visible residue.
- Avoid scheduling your delivery and/or application on a day when heavy rain is forecasted. If you do take delivery and rain is in the forecast make sure to cover the pile with a tarp.
- Do not install if rain is in the forecast. As noted above, you should try to find a window of no less than 48 hours of rain-free weather as critical drying time is needed.
Renewing “Washed” Product
In the event product “washing” does occur, there are options available to amend your mulched areas. If the material has been delivered and is in a bulk pile, the washed product can simply be mixed in with the rest of the mulch as it should be just a surface wash. There will be enough colored mulch in the pile to blend in with the surface material. There will be no product loss.
If the material has been applied to the landscape, there are two options to remedy the situation (keep in mind the same critical drying time is needed):
- Lightly rake the surface. Colorant loss is normally limited to the top half inch of material. Mulch is normally applied at a two-inch depth leaving plenty of material to cover the surface once it’s flipped over.
- Top coat the surface with an additional half inch of fresh color-enriched product.