I just started trying the preen this season. My understanding from reading the label is that you have to eliminate all the weeds first and then apply the preen. I applied it to my new beds but I'm still seeing weeds coming up so perhaps I'm missing something with the application. I keep picking them out as I see them sprout up.

Julia

I've been using it for three years. It is wonderful. You have to weed first, though. You will get an occasional weed, but I rarely have to pull any. I do put it on rather heavily though. The Preen hasn't hurt my daylilies.

kay

I use Preen in all my gardens. It won't kill grass and weeds that are already growing. Preen stops seeds from germinating.
Round up is what kills vegetation and it will kill all plants, including your daylilies. I cover my plants with paper grocery bags and then do a controlled spray if the grass is thick. If it's not thick, smother it with mulch like newspaper or as some on this forum have suggested, use cardboard.
I like to weed my flower beds in early spring, sprinkle on Preen then cover with clean straw. I have very little trouble with weeds, even into the next spring. I also edge my beds with a shovel to try to keep the grass out in the first place. That can be a challenge.
Hope this helps.

Nancy VB

I have been using Preen around daylilies for years with no problem. This year is different! The Preen has been changed & is now not working in my flowerbeds. It seems like they took the Preen from more of a pellet form & turned it into more of a fine particle form. Not working this year for me. I have wrote the CO. but have yet to hear from them. After 5 years of weed free beds it is hard to go back to picking weeds out & tiny tree seedlings. The price of Preen is not cheap so I won't be buying it anymore.

If you have a grass problem in your beds, the Ortho Grass-B-Gone or Ornamec Grass Killer can be over sprayed in the daylily beds without harming the lilies. I used that earlier this year in a bed that had developed a serious crabgrass problem and that bed is now grass free.

Linda

Linda: Did the sprays change any of the daylilies bloom colors?

Julia

I haven't noticed the spray causing any color change with the grass killers I mentioned.
Linda

That was my question for daylily growers. I just made a new daylily bed for my newly purchase daylilies from online. These were mature plants. So would preen hurt or shock a transplanted daylily?

No, Preen won't hurt them. Just be aware that Preen won't kill existing weeds--it just stops the weed seeds from sprouting. Also it won't work on all weeds, such as asiatic dayflower.