Hi greengardener,
First thing you should do is familiarize with the friendly and knowledgeable folks at the Winter Sowing Forum. Seeds can be sown (almost)any time of year but Winter Sowing has some great benefits that can help anyone grow (amost anything) successfully from seed.

Second item: Don't over amend that bed by your butterfly bush. Both it and the plants you want to put there are happier in less fertile soil; most of them are meadow and/or plains plants and Very adaptable to poor soils. A light mulch after you can tell the seedlings apart from the weedlings will work best; and I would suggest you wait til early spring next year (just when the soil starts warming.

Cheers and Happy Gardening!

Here is a link that might be useful: Trudi's WS website

In addition, you can use the winter sowing method and summer sow right now. I'm winding down my summer sowing to give my perennial seedlings enough time to mature for fall plantout, but I do plan to sow a few more containers this week.

Try it! We will coach you through it on the Winter Sowing forum.

Like you, I had very little luck direct sowing seeds so I followed a friend's advice and tried Park-Starts. It works for me, ten plus years now. You can see Park-Starts and other options for growing seeds under lights at Parkseed.com. Good luck.

I winter sowed for the first time this year and got incredible results. I used the clear gallon milk containers and put them out in Feb. Take a look at the winter sowing boards. These people know what they are talking about. I already purchased a bunch of seeds to put out this winter. I also sowed some annual seeds indoors as well as some outdoors. The outdoor sown seeds took until the end of July to catch the indoor sown seeds. So for annuals you may want to start them indoors if you want that early season showing.

Roy