Aphids are bad bad. Easy to squish by hand if you don't want to use chemical (malathion) spray or strong hose blast that may break flower stems.

But I'm suspicious it may be scale. They require more of a scrape motion to clean off. Their shells are not fully hardened this early in the year.

Thanks. I garden organically so malathion is not an option. Any suggestions for how to verify that what I am seeing is scale? I sprayed them all with dilute soapy water earlier. Should I just take a moist paper towel to them if it is scale?

Ladybugs are your organic answer to aphids.
You can either order them online or some nurseries carry them.
As long as there is food in your yard, the ladybugs will stick around and devour all the aphids.
They are amazing!

Good luck and happy gardening!

Terry,
Aphids can be green, red or black --- you can see little legs with a magnifying glass --- they are more oblong than round. They are capable of moving. The soapy spray will knock them to the ground where they will die.

Scale are more like rounded limpets (?) --- they anchor in place. On iris this is up and down the center of the leaf. Often you see a whitish stuff in conjunction with scale. Usually they appear later in the season. The sprayed soapy mixture will not remove scale (maybe if they are really really young). A paper towel would be too soft. Your finger nails or a credit card work well.

Terri, I have had the occasional aphid outbreak over the winter and this spring. When I notice them on a group, I get out my aphid spray. It is a spray bottle(16oz) in which I put a tablespoon of canola oil and about 3/4 teaspoon dishsoap. I then fill to the top of the bottle with water. I squirt til it drips off the leaves. It seems to keep them from worsening.

I do agree that they are not devestating to the iris but they do leave quite a visual impact on the leaves after they suck away for a while.

Good luck,
Meredith

Aphids are soft with tiny legs. Scale have a hard shell and no legs.
Laetitia