Mulch should be replenished or replaced as you start to see signs of decomposition, soil erosion and discoloration. And you'll mostly likely need to remove and replace all mulch after 5-6 years.
So, should you remove old mulch? Expert green thumbs contend that getting rid of last year's mulch is completely unnecessary. Mulch gradually breaks down, adding beneficial nutrients and other organic matter to the soil. Removing pre-existing mulch every year only ends up to be extra work and a needless expense.
Our view is that mulch should be put down annually to compensate for the decomposition of the wood and bark fiber and the graying of the color. When applying annually, a 2”- 3” layer of mulch should be a sufficient depth. Mulch that is applied too thick can suffocate your plants and starve your soil for moisture.
HOW LONG WILL MULCH LAST? Mulches vary in lifespan from approximately 12 months in the case of leaf mulch, to approximately 3 years in the case of woodchip.
Turn it Up
Every couple months you should be turning your mulch since the top layer will naturally compact with the soil. Mixing and turning mulch can help deter mold growth under the top layer, allow it to breathe and help water flow through more easily.
Several research studies have shown there is no nitrogen depletion problem for established wood plants using fresh wood chips. If you are still concerned, you can let them age before using, but it is not necessary.
Mulch is not intended to last forever and will break down completely in about five to six years without any intervention. However, it is often preferable to replace your mulch more often. If your primary concern is aesthetics, you might wait until the mulch is no longer attractive or pleasing to your eye.
The practical life-time of mulch can be anywhere from 4-7 years. This is how long it takes for a layer of mulch to completely break down, although it depends on a number of different environmental factors (e.g. in direct sunlight, covering very wet ground etc).
In general, mid- to late-spring is mulching season; this is when the soil is warming up from the freezing temperatures it experienced all winter. Mulching too early will slow down the warming process, which the soil needs to do its job.
Reusing old mulch is as simple as buying new supply to cover the existing layer. Use a rake to loosen it up before adding that fresh layer. Remember that the total recommended depth of mulch is no more than 3-4 inches.
All organic mulch breaks down and eventually turns into soil. Mulch will become ineffective at suppressing weeds as it becomes compost. Below the compost layer, is what used to be composted mulch, but is now soil. As mulch is topped up every year, the layers of mulch, to compost, to soil will keep building.
Stone is the longest-lasting mulch, followed by landscape fabric. Black plastic and rubber mulch last a long time, and help with both heat and water retention in the soil, though they're also more expensive than stone or landscape fabric.
For growing spaces, your best mulch option is wood chips. For pathways and barren, decorative areas, stone chips are a good choice. Heavier mulches are less prone to washing or blowing away in inclement weather.
It normally happens in a damp or wet condition when bacteria start eating your mulch. The bacteria continue to grow and create spores which eventually grow into the dog vomit mold you are likely accustomed to. Mulch doesn't necessarily cause mold but rather works in a symbiotic relationship with the mold.
To calculate mulch in yards, it is essential to note that one cubic yard of material will cover an area of 324 square feet at a depth of an inch. To determine the total amount of mulch needed, the formula is: Square footage x desired depth (in inches)/ 324.
We recommend aged hardwood mulch, applied in a light layer, around your flower beds. Well-aged wood mulch is an ideal choice for flower beds, as it adds nutrients to the soil as it decomposes. Softwood mulch, usually made from pine, can add a bit too much acidity, and doesn't decompose quickly.
How deep should your mulch be? You should spread your mulch to be two to four inches thick. If your mulch is too thin, then weeds can push through. If your mulch is too thick, it prevents water from reaching the soil.
Spring is usually known as the typical season for mulching your garden, however mulching leading into winter has massive benefits. A fresh layer of mulch during winter will prevent weed growth and erosion, make maintenance easy and reduce the need for herbicide application in summer.
Fresh wood chips and barks can contains toxins such as tannins that will damage plants that they are applied around. The trick is to age such materials by leaving them in a pile for several months to allow the toxins to dissipate before they are used in the garden.
Organic mulch decomposes over time, so it will need to be replaced eventually. A typical mulch may last about five years, but this timeframe can decrease depending on the type of mulch, weather conditions, rainfall, sun exposure etc.
To promote decomposition, mix leaves with grass clippings or other materials high in nitrogen. If possible, shred the leaves prior to composting. The smaller the size of the material, the faster it will decompose.
Old mulch can be put in your compost bin if made from organic material. However, the type of material used in the mulch will determine how long it will take to completely break down in the compost. For example, Woodier materials take longer to decompose than softer materials, such as straw.
Because wood chip mulches are harder for nature to break down, they actually pull more nutrients from the soil than they add back in. Also, mulch looks tired after about 1 year, and most people like to refresh it each year.