This question is one many gardeners ask every year, and there seem to be different answers from even the most experienced sources. When you care a lot about your soil health, plant growth, and the overall look of your garden, how to use mulch in the Fall is an important topic.
There are two approaches to what to do with existing mulch:
Remove all the old mulch, lay down a thin layer of compost, and then place newly purchased mulch on top.
Leave the old mulch to deteriorate into rich organic matter and place new mulch right over it. (This one is certainly easier!)
Here are a few questions to think about when deciding which approach is best for your garden. Then, you can purchase the right amount of bulk or bagged compost and/or mulch to give your garden a beautiful Fall look, and prepare your soil for next year's growth.
What Is Your Mulch Made Of?
Mulch comes in a variety of materials from rubber to organic wood chips, and our post, "What's the best type of mulch?" can help you determine which type is best for you.
If you're currently using something that doesn't break down over time, you don't need to replace it! In this case, it is particularly important for you to pull off the existing mulch, put down some compost, and then put the old mulch back. Your garden requires additional nutrients every year and, since the mulch isn't providing these, you need a compost or soil amendment to help.
We recommend natural, wood mulches, and these require replacing them every six to 12 months. Bulk mulch is quite affordable and sustainable, so you can replenish or replace it every spring, Fall, or whenever you prefer to do aesthetic upgrades to your flowerbeds.
How Much Has Your Mulch Deteriorated?
All-natural mulching materials break down over time. The speed depends on everything from treatments and soil makeup to how much rain you got during the year.
If your existing layer has all but disappeared into your topsoil, there is no need to scrape it up before adding a fresh layer. In this case, you may not need to add compost because the mulch may have provided the nutrients and organic matter that your soil needs for next year. (Using a soil test is the only way to know for certain.) If the mulch is particularly compacted, shows any sign of unhealthy mold, weed growth, or insect activity, getting rid of it (or, at a minimum, scraping it off and reapplying it) may help.
Whatever you choose, you will need to add at least some mulch to your garden to ensure that your soil has the right amount of mulch on top to protect it during the winter months. In a flower bed or around shrubs and trees, the ideal depth is approximately two to four inches; anything thicker than this and rainwater might not get through to the roots. Before adding more, however, fluff up the existing layer with a rake or your hands to determine the correct amount--you may need much less than you think.
With great bagged mulch and bulk mulch options around Manassas, VA, you should be able to find an affordable and quality mulch that works for you.
Do You Want to Improve Your Soil Quality?
As organic mulch breaks down, the nutrients flow into the soil below it. In fact, the bottom portion of your mulch, where it touches the soil, may already be becoming a natural, garden-made compost.
If you have not done anything to improve your soil's health recently (or ever!), then you should make sure to improve your soil quality between planting seasons. Our local soils in Northern Virginia tend to have a lot of clay, and the organic matter in compost will be especially important to help break it up. In this case, it makes sense to buy bagged or bulk compost near you and add a thin layer to your garden. In this case, you can remove the old compost with a rake (but do not throw it away!), lay down the compost, and then put your old mulch back over top of it. You can then top the garden bed off with a fresh layer of mulch. This fresh layer helps make it look pretty buy also ensures you're getting the benefits from your mulch.
In most cases, there is no need to remove all your old mulch before laying down a new layer in the Fall. Over time, natural landscape mulches will add their nourishing organic elements to the soil and make your garden's soil healthier. Top things off with the best bulk or bagged mulch near you to help your yard look its best, and to cut down on maintenance tasks and water needs throughout the year.