Try tomclothier.hort.net.... Another thing would be a general description on how to germinate seed... ecgardening.ccc,cornell.edu there is a pdf that is very helpful

There is no way a pre-emergent herbicide can distinguish between weeds and what we may consider non-weeds. They are simply all broadleafed plants and the effect should be the same. That's why it is not recommended to use pre-emergents where you will be sowing seeds or allowing self-sown seeds to germinate. I would attempt using Preen or some other pre-emergent before I'd resort to RoundUp, even in clear areas under the tree canopy. There is some evidence that repeated use of RoundUp across a tree's root system can have damaging effects. I realize you may be dealing with a great many seedlings, but I'd recommend manual removal over and above anything else. I deal with freely seeding maples myself and understand what a PITA it is to get rid of them. Raking up the samaras when they fall would be my first step. The less of these that remain on the ground, the less germination that will take place and many fewer seedlings to deal with.

I have about 200+ Passion flower plants. They are the Passioflora Incarnata. These are the blue/purple. I would be interested in some bulbs. jpotts461@gmail.com

Large seeds are probably better sowed directly where you want the plants to grow. Very tiny seeds can be difficult because of the possibility of drying out. So it depends how diligent you can be, and how organised. Are you going to remember where you sowed things and where you need to keep the area moist? Or are you going to be like me, wandering around the garden in a vague way, trusting to memory, getting side-tracked. And wondering why the ___________ [fill in blank] never germinated. Another thing you have to watch out for is the frustrating cutworm. He is a caterpillar, in his larval stage, and will become a moth. But on the way to getting his wings he spends his time slinking about chomping through the stems of the very plants that you have sown. Like cucumber seedlings. You will see them - both the felled seedlings and the caterpillar - but you won't suspect the caterpillar because of his air of innocence. And he's so smooth and attractive. (You probably only see them though if you've got your hands in the soil, fiddling about.) So, you need to protect the seedlings of things like zucchini, pumpkin, cucumber - all those nice fleshy seedlings. Little seedlings possibly aren't attractive to cutworm. (You can use something simple like a plastic milk bottle with its base removed, and no lid.) So, in summary, the main thing is to keep the area moist. And to know how deep to plant seeds. Little ones are planted very shallow. Big ones, about .5 to 1 inch. Don't walk on them. Don't stand on them admiring the garden. And there is just one exception when it comes to watering: with peas or beans, water at sowing but not again until they have germinated, or they will rot.