zone 5...weeds ahead of Iris...okay to use Preen ?

Does Preen have a detrimental impact upon Iris growth and bloom ?

thank you

I've never used that one myself, but most weed killers out there, will damage the iris bloom to the point it won't even look like an iris. Other's will cause the bloom to turn white or transparent, or have white streaks, and /or shrink the bloom, and cause the bloom petals to become pointed instead of rounded. Some broad leaf weed killers will almost destroy the iris plant entirely.

Now if they have already been sprayed (or the wind has blown some weed killer onto a nearby iris) and the damage is apparent come bloom season.............. the good news is that the new increases will usually comeback OK and bloom is usually normal too by the following year.

~Margie

Preen is a pre-emergent and doesn't damage mature irises at all, but it also won't do anything to kill existing weeds. It will, however, significantly reduce germination of new weed seeds for a matter of months after application.

Laurie