Do I have to remove the mulch

==>>> not unless you want to do endless weeding ...

you have 2 choices .. imo ... [i think i added a third]

winter sow.. or start your seedlings elsewhere .. and then move them into your gorgeous bed ... of course.. you would start by collecting the seed as it ripens ...

or.... you make a one foot by 6 inch wide bare earth place.. sow the seed.. and in spring.. move them around when they are small and young ...

in years.. as your mulch start to break down.. you will be able to get some seedlings on top ... but if that happens.. you will also be getting weed sprouting.. which is usually when you would add a new layer of mulch ...

one other idea.. would be to have a nursery bed...

ken

Thanks ken, I like the idea of a nursery bed!

The general idea of mulch is to suppress seeds germinating. So yes, Ken's advise is apt.

btw ... you posted this in the perennial forum ... and you planted perennials ...

and now your asking about self sowing annuals ....

which is just fine ... but how exactly do you define your garden.. whats your goal ... you can surely have both together.. but then you have to figure out how to do it ....

e.g. the mulch is perfect for perennials.. but now you confused about reweeding annuals ...

again.. winter sowing of perennials might be your next step for those ..

ken

I started my perennials from seeds in pots of growing medium. Plenty of other plants have grown all around them with zero help from me. I put down mulch 4-5" thick over corrugated cardboard. That doesn't even slow them down. I'm thankful for the plants that reseeded; I've given up on the invasives.