need i.d. of iris borers, please

i was pulling yellowing leaves off my iris and found a soft rhizome. i poked it and it was rotting. inside the rot was a tiny little worm. is this an iris borer? also, roly polies are eating my iris. i am using triazanon. d.e. did not work.

If the soft rhizome has a really gross smell, then it's iris rot.

Here's a picture and a couple of articles.

http://www.ppdl.purdue.edu/ppdl/weeklypics/Weekly_Picture7-26-99.html

http://hgic.clemson.edu/factsheets/HGIC1167.htm

Sandy

last year i lost about 500 different varieties of iris. mainly, i think because roly polies ate them up. i have these iris on raised rows. i put mulch between the rows. they are sitting on the west side without shade all day. this year i covered the tops of the rhizomes with soil. my soil is clay. a friend in california keeps telling me to uncover the iris. but i am afraid that the heat also dehydrated them last year. another problem i have is this. around the iris garden are several blobs. they appear to be browned meringue and are squishy. usually they are sitting on top of the dirt or between the rows. sometimes it covers a plant. what on earth is this? i guess what i need to know is do i uncover my rhizomes until the spring rains are gone and then should i put, instead of my hard clay soil, maybe potting soil without fertilizer on top to get them through the heat and dryness of summer. i am treating the roly polies with triazinon. and i understood from the first article if i use some kind of chemical to treat the soil i can kill the hatching moths. i have never heard of that chemical. is there another name for it?

I'm afraid I know nothing about the sorts of insect pests or fungi (blobs?) you have to deal with down there in TX. I can tell you, however, that borers do not exist that far south.

If you need to protect your rzs from dry summer heat, I recommend covering them with about 1/2" of unamended, coarse sand.

Laurie

That is a lot of loss. I'm pretty new to iris, but the ones we lost were too wet, planted too deep, or were fertlized with manure.

I have no idea what your blobs are, but I have noticed more bugs on the blooms in areas where there is mulch.

Laurie's suggeation to cover them with sand sounds like a good idea, the clay is probably keeping them too wet. We have very hot summers here and the rhizomes do fine with their tops exposed.

Good luck :-)

Sandy

The worms and roly polies are just cleaning up what's already dead or dying, I wouldn't bother using a pesticide to try to control them. I'd lose the mulch and make sure your iris are in an area that drains well. Find a local iris society chapter and ask them what they do as far as mulch and summer heat.

Here's part of an article I found:

"Pillbugs prefer damp areas, which is why they are often found invading homes through openings close to patio doors, laundry rooms and basements. These bugs feed on decaying vegetation most often found in mulched areas around homes. The damp conditions and decaying organic debris are contributing factors"


Neil

Neil, that makes sense to me. :-)

Sandy

i know the pill bug thing makes sense to everyone but i promise you that they are eating my iris. they eat right into where the leaves come out of the rhizome and then they stop. last summer we had hardly any rain. the only thing that stopped them was me putting the dirt on top of the rhizome and/or triazinon. i always though pill bugs did the clean up too. but they were eating my iris. but the idea re: sand instead of other soil makes sense. that is what i will do. thanks.