If you had mulch like stone, plastic, etc., this is not biodegradable material. We are only speaking of materials such as bark, leaves, straw, etc.
The answer depends on whether last year’s mulch is still in good condition to be used again or whether it is no longer useable and becomes waste.
How do I tell if the mulch is still good?
You can determine that by scooping up some in your hands. If it breaks down into fine particles and is hard to distinguish from the earth in the garden, it is time to replace it. If it has retained the look and feel of when you bought it, you can most likely reuse it, UNLESS you had disease problems in your plants, flowers and/or bushes last year.
How do I re-use Mulch? Do I have to buy new as well?
First gather up the old mulch and set it aside in order to prepare the area you are going to do planting. Then if you have compost you want to add to the soil, do so and work the compost into the soil and then plant your seeds or transplant the plants, flowers and shrubs you have recently bought for this year – then and only then re-apply the mulch you have over the top.
What if I am still not sure if the mulch is still useable?
You spend a lot of time preparing and then growing your garden in order to get the results you want. If you are unsure, be aware that you can still use the older mulch. BUT, you would work it into the existing soil as organic matter so it can work along with the compost. And buy new mulch to apply over the new seeds and transplanting you are doing for this season.
What about “Living Mulches”?
This kind of mulch is used to cover your vegetable garden or flowerbeds to protect them from winter’s harsh elements. You can reuse it the same way you would use questionable mulch from last year. Sow it into the earth below as it contributes nutrients to the soil.
How do I dispose of old mulch?
You can check with your city or community to see what guidelines you must follow to dispose of mulch.