Probably not with good results unless it's very well composted (finished). Hardwood mulch has greater than 1000:1 carbon:nitrogen ratio & will tie up all the nitrogen you can give it. Conifer bark, on the other hand, has a C:N ratio closer to 300:1 and because of the goodly amounts of suberin it contains (suberin is a lipid that inhibits micro-organisms from cleaving hydrocarbon chains in woody material) breaks down much more slowly, making N depletion much less a problem.

Al

It depends on the mulch, the size of the particles and consequently the water holding propertys of the mulch.
I know people who plant directly in finely ground ( or chipped) pine bark with OK results...but a little dilute fertilizer is a good idea. But.....why not plant in the soil beneath? Or make a "planting pocket" of soil in the mulch?
Linda C

I'm with Linda - need a little soil around the plant itself. As it grows it will get stronger and be able to handle more - then it can spread into the mulch.

My two cents...
plants need dirt.

Plants need soil with available nutrients. People who have success planting in mulch are using a thin layer of mulch, I suspect, with the plants sending roots down into the soil.

A little soil won't cure this person's planting's ills. Even if he waters adequately, he's actually talking about planting in hardwood mulch, not in the soil. Linda was right about particulate size making a difference when mulch is incorporated into soil. The worst case/scenario for N tie-up, or depletion if you prefer, is planting directly into a hardwood mulch.

E.g I make all my own soils for everything I grow and for other people. I usually use pine bark as the highest % of material that goes into the soils. This year, I was unable to get the composted pine bark I usually use & had to settle for a product called 50-50 mix. It is bark & other woody products, and includes some peanut shells. Using it in the same formula that has yielded spectacular results in past years has left me with symptoms of moderate to heavy N depletion. I normally use a 2-3-1 fish emulsion to water my flowering stuff, but this year, to correct the N problem, I've had to go to 5-1-1 fish mix AND supplement with a high N slow release.

Some research into the suitability of various soil components will confirm that hardwood mulch, unless it's finished compost, is a poor choice as a grow medium.

Al

When is the best time to plant rhodendrums?

Can Rhodendrums survive in Southern Alabama? Is weather a factor? No one seems to grow them there.