its all about how deep the mulch is...

most seeds need to contact soil .. so if your mulch is so thick that the seed never makes it to soil.. then you would have the reduced germination.. or lack of ... until the mulch start composting itself over the years ...

on the other hand.. to thin.. and whats the use of doing it.. lol ...

so i dont know what to tell you .. about a happy medium ...

what you can do ... is to time out your application of new mulch ... not too early to bury last years seed ... but early enough for the seed in fall to fall on top .. and go rather thin as to thickness ...

though you might not get a thick crop... seed dropped on top of mulch.. some can germinate thru it all ...

and dont forget .. when they are in the second true leaf size.. you can move them around ... especially on a rainy day ...

ken

That whole mulch issue really is a conundrum. You are absolutely right that mulch is very helpful for weed suppression and moisture containment. But it also prevents reseeding of some "perennial favorites." I solve that problem by wintersowing. Any plant that I wish would reseed, I carefully watch for seed to ripen and collect it. Then I sow it in a milk jug in January so it will sprout in time for its traditional spring or summer appearance. Certain especially picky plants, like columbine and larkspur, I do avoid mulching, since they seem to do so much better left completely to Mother Nature.

Martha

Unless it is an exotic annual or perrenial the value of having mulch deep enough you don't to weed seriously negates their ability to reseed. For over the counter seeds what is a couple bucks a year verse weed pulling labour?

SCG

Mulch that prevents weed seeds from germinating is going to prevent your garden plants from germinating. If any plants have special ninja abilities to sprout anywhere, it's the weeds. The plants we actually want are the ones that require effort.

I use mulch. I get little to no re-seeding of the things I want with the mulch, but that's OK. I just sow anything I know I want more of. For me, seedlings have a better success rate if they are in a definite, labeled spot. This way I pay attention to them, water them, notice if something's eating them, and am less likely to step on them or yank them out thinking they're weeds.

I like Ken's idea of leaving a clear space around the reseeders. Sounds like a good compromise.

What I like to do for my beds with good re-seeders in early spring, is just to rake out the left over mulch to the side. Never failed for me :)

Vera

What kind of mulch are you using?

I use cypress mulch, about 1-2" around the plants in question. Some seedlings of other plants grow through, just not the ones I wanted. But I don't know how long those seeds have been there or what random struggle they went through to be in contact with the ground or grow through the mulch.

Although I had wanted automatic self-seeding (because that's what these plants had a reputation for, right?), I guess it never hit me to do manual seeding. I definitely can collect the seeds from the plants, but just never thought about throwing it under the mulch.

Even with buying columbine seeds, I had not heard of the stratification until this year. I was always just planting it in spring since that is typically when people think to plant, and it just would not come up (even sitting another 1 year under the mulch)

I guess it's an example of thinking so narrowly that the other easy solutions didn't even come up.

Thanks for that idea.

This post was edited by gardenper on Sat, Apr 26, 14 at 8:48

I have been lurking here a bit. Hi, I depend on several plants reseeding in my informal garden. Annuals are things grown from seed in my garden. I do not buy them but rarely. I move the mulch out in places that I want seeds to prout during their optimum sprouting time and then re cover after they have a good start. I mulch heavy in early summer for the big heat. Mostly it has broken down by seeding time. I also run a garden claw through th much, shaking things up during the time the dried seeds on the plants have dropped their load. I have no idea if that is a accepted gardening process, but it is mine. I use mostly composted oak leaves as mulch. I do get sprouts of columbine, ipomopsis, poppies, and penstemons. Well, enough that I can then move them to where I want them.

Lots of good ideas above.

I think the removal of mulch early on, thinning, transplanting, and then putting the mulch back later is the only surefire way to get lots of free seedlings AND have mulch to keep down weeds and hold in moisture. That's alot of work, time, and trouble. And timing of both processes is very important.

There are plants whose seeds come up through even thick mulch. Those are some of my favorites: Snowflurry verbena, Penstemon tenuis, Cardinal vine, and Cleome.

Most years I have lots of free flowers that come up in my vegetable beds. I add compost to those beds each year and, a lot of seeds survive the composting process. I just lift those baby plants and put them in my flower beds where I want them.