I read in many places that pine bark is light weight and heavy rain will wash out the mulch. Can I use two layers? First layer of Pine bark and second layer on the top of Cedar mulch. So the pine bark will decompose and provide nutrition to the soil and top Cedar layer will protect the mulch and keep it in place. Is this a good idea?
Thanks.
Yes. That will work to help keep it in place.
You can also layer the Pine Bark Nuggets with Shredded Pine Bark Mulch, if it is available. I have slight flooding problems during heavy rains, and I have always used that mix. It has worked well.
But, recently the garden centers were out of Shredded Pine Bark Mulch, and I had to substitute Shredded Cedar with the Pine Bark Nuggets in one area. It flooded the next day, and it didn't move, at all.
The only disadvantage is the cedar not breaking down as fast, and providing as much nutrients (as you probably already know). It also might discourage beneficial bugs, to some extent, which is not something I wish to do.
(Edited) I probably should have mentioned that in hurricane season, we have to move our cars to higher ground, so buoyancy of the mulch is a major issue.
Even though I suggested an answer to your question, I am curious about what works best for you and everyone else, too.
Here are some links:
http://safarilandscapedesign.com/landscaping-with-garden-mulch/
http://safarilandscapedesign.com/landscaping-with-garden-mulch/
And here is one that came up from this very site! What are the pros/cons of different mulches?
Be careful using dirt to compost bark. The decomposition process will initially rip a good amount of nitrogen out of the area. If you're mulching over an area with roots near the surface, it could be affected. (Easily countered by feeding, though.)
I haven't had any trouble with pine bark mulch washing away. While Cedar is my go-to (because it interlaces very well and you can turn a blower on it without it dashing off), I've used pine bark nuggets and don't find them any less effective than most mulches. And on the positive side, if you have leftovers you can compost them a heck of a lot easier than shredded cedar.
But yeah - should be fine. If the rains are heavy enough to carry away 2" of tamped-down pine bark nuggets, you have rougher things to worry about and should possibly consider starting to gather two of every animal.
Yes some mulch can wash away but that also depends on the slope of your area with mulch, any edging that might retain said mulch, and how heavy the rain really is.
