Confused about Preen application

[Blueindigo1954]

I am in zone 5. I have struggled a lot with weeds coming up during spring in my flower garden. I was advised to apply Preen before the weeds start sprouting. I suppose I should have done that during Fall.

I have bought some zinnia and Siberian wall flower seeds and like to mix them with garden soil and throw in the flower garden.

If I apply Preen now, wouldn’t it stop the flower seeds to grow also?
I understand the application of Preen should be done *after* the flower sprouts are about 2” tall but the weeds start sprouting before the flower seeds sprout:

So I am confused about when to apply the Preen. Could anyone please enlighten me on this ?

Thanks

 

[Oliver Buckle]

You are right, applied now it will stop your flower seeds germinating. Preen breaks down in the soil over a few months though, so if you apply it well before you plant the seeds you want you should hit most of the weeds that come before them. That should have been November or early December for the first lot of Preen to plant now. Not many seeds will arrive between December and mid February. Then when the ones you want have germinated you can use it later to keep free from seeds that arrive .
Sorry, you missed the boat a bit this year, suggestions :-
Apply the preen to the garden to get the weed seeds. Sterilise some soil in the microwave, or otherwise and germinate your seeds in that in containers, then plant them out in the garden. Or plant the seeds in short lengths of gutter so you can slide them out into shallow grooves when they are germinated. I say short lengths, if they are too long the soil tends to stick and not slide out nicely, you could probably get something nearer the random effect like that.