Garden and landscape experts will tell you that it's unnecessary to remove last year's organic mulch. Laid down in any garden, mulch is supposed to break down gradually and add beneficial nutrients and matter to the soil. Thus, the longer mulch lasts, the more nutrients go into the soil.
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.
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.
Remove old mulch by shoveling it into a wheelbarrow. Dispose of that or add to a compost pile. Smooth and level the area to be mulched with a landscaping rake or by hand. Apply a layer of plastic mulch or fabric landscape sheeting for extra weed control.
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.
A square-point shovel works best for moving mulch materials such as pebbles, wood chips and sawdust. A pitchfork works well for loose straw mulch. If you want to move a pile of lightweight, fine mulch, such as pine needles or dry sawdust, then a large scoop shovel moves the most material the fastest.
In most cases, you will only need to replace your mulch once a year. In order to determine if you need to replace your mulch, make sure to check the mulch at the beginning of the spring to see what kind of condition it is in.
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.
During the summer, fresh woody mulches become hot from decomposition, which dries out the mulch. Fungi then colonize these dry, dusty mulches, making them thick and matted.
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.
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.
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.
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.
One of the best mulches to prevent weeds in your garden is wood chips, also known as wooden mulch. Wood chips, including graded fine bark or pine mulch, won't decompose as quickly as other mulch types, giving you a long-term solution to weed control.
Bark mulch is the best choice for use as a weed suppressant as it inhibits weeds in two critical ways. First, by applying a thick layer covering the soil, bark mulch deprives the weed seeds in the soil, and their resulting seedlings, of the sunlight desperately needed to germinate and thrive.
Wood Chips Have Many Uses
Mulching with wood chips conserves soil moisture, reduces weeds, and cools the soil. All of these benefits help to make your plants healthier. Mulch can help your plants grow faster with fewer insect and disease problems.
You can apply a granular fertilizer on top of the mulch. Water in. It will make its way to the plant roots. Or you can apply a liquid fertilizer on the foliage and the mulch.
Be sure to only place mulch on top of your soil rather than plowing it in. Let the soil organisms be your “plow” and bring the nutrition into the soil for you as they digest it.
Always wear a mask and gloves when handling soil, compost or potting mix. Rinse gloves afterwards. Open bags of potting mix slowly and in a ventilated space. Direct the opening away from the face to avoid inhaling the mix.
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.