the good and the bad - HELP!

Good morning everyone! Last year I was so inspired by all of your wonderful pictures and by the gardens I visited that I redid my iris area and planted lots of new ones. I tilled in lots of sand for better drainage and my iris seemed to do wonderfully over the winter. Yesterday I went out and weeded and noticed some things that have me concerned. I would love to hear any advice you all might be able to give me.

first concern... I have noticed that some of my leaves have started showing spots already. I seem to remember that there is something you can spray them with to get rid of this disease or virus? What would you recommend?

my second concern is the bigger one - a lot of my iris have some rot going on. I didn't notice until I was up close weeding. Is this something that might kill the whole plant?

The iris area is at the bottom of a bed that has a gentle slope. I thought adding the sand would help. The top part of the bed is full of daylilies. It's a little hard to see in this picture but the iris stretch across the bottom next to the road where it is the hottest.

My little bit of good news is that I had my first iris bloom yesterday on TRAJECTORY. I guess as far as the rot thing, I will wait and see what happens. I may need to think about moving these to a different higher location. :-<

Again, I would be grateful for any advice!! wahh!

Lily: I'm far from an expert, just started growing irises last June. I can't tell for sure but your pictures look like the r/z are planted too deep. It might be just your pictures. Are they above the dirt ?

Hi betterbloom! Thanks for the suggestion. I went out and took a picture of a cluster of some of mine. The rhizomes are half out of the soil. The picture I posted above showing some rot was taken from the back of the plant. The rhizome is stretched out the other way and the leaves are hiding it. I finished my weeding today and after pulling off the rotten fans they look better today but my guard is up lol. Plus we are supposed to be getting a big storm sometime - its been predicted all week and hasn't hit yet though. :-&

Does this look like an ok planting depth betterbloom? I appreciate you helping! I'm pretty new to iris too. This is going to be my second year and my first for most of the iris planted last year.





This message was edited Mar 30, 2007 4:49 PM

Lily,
They look okay to me, but like I said I'm pretty new to irises myself. Maybe someone will come along and help you out. I live in the desert but don't plant anything in the sand. I'm guessing someone from your zone might be able to help you out more than I can. I don't have problems with rot , the sun here fries everything !

It sounds like its perfect for iris where you are. Have you tried any of the Pacific Coast iris? I swoon over pictures I see of those but know better than to try them here.

I was so surprised to find out that you all don't get plagued with iris borers west of the Mississippi! Between the humidity and the wet springs and falls its challenging to grow some of the newer hybrids here. I had some old pass along iris that were given to me about 7 years ago and they seemed fine. When I took those out and planted all the new ones I was surprised to see that they didn't seem as hardy. But the same holds true for daylilies which I am a lot more familiar with.

I heard some say that they buy from supplies in their region because they grow better, don't know for sure if it's true or not. I know I don't buy irises from that part of the U.S. just because of iris borers. Even tho they can't survive here I don't want to take any chances. I only have two people that I get my irises from and Iam happy with them so far so I stick with them.
I just started on daylillies so don't know how they will grow here. I imagine if the nursery sells them they will do alright.

Do you get snow or ice in your part on TN ?

Lily,

Your irises look like they're planted at a perfect depth to me, though they do look like they are planted a bit too close for optimal health. Fungal leaf spot, which is probably what you have in that first pic, is easily spread from plant to plant when infected leaves are blown against each other or when fungal spores are splashed between plants during rainfall or overhead watering. That's one reason why it's best to leave generous spacing between irises when you plant them; it slows down the spread of leaf spot. Also, leaves stay healthier when they have excellent air circulation around them and plenty of direct sunlight, both of which are diminished in close plantings.

There are several strategies to avoid or minimize leaf spot in addition to keeping irises properly spaced:

1) Avoid overhead watering.

2) Remove and trash or burn (do NOT compost) infected leaves or parts of leaves whenever spotting appears.

3) Spray healthy leaves with alternate fungicides every 10-14 days throughout the rainy season. You must first remove unhealthy leaves or parts of leaves because most fungicides are preventative, not curative.

As far as rot is concerned, it's not at all uncommon to see rot in an early spring garden when the soil is particularly damp and cool and the plants are stressed after a long winter. I personally don't treat for rot because I prefer not to grow irises that require coddling in my climate. Often a rotter will spontaneously recover once the soil warms up and dries out, but sometimes the rot will spread and take out the whole clump. I don't sweat it either way. In your situation, though, I'd make a point of moving those irises onto higher, drier ground where they'll stay healthier.

Laurie

Thanks for all the great advice everyone.

Hi phicks - yes we get snow and ice here. In fact in spite of our current warm temps, it is not that unusual for us to get snow in April.

Hi laurief - thanks for all the great advice. I will go get some fungicide tomorrow. Is there any particular kind you recommend switching back and forth? I don't water the beardeds at all so I'm ok there. I was relieved to hear that a little rot is not unusual in the spring before it warms up. That was what I was hoping to hear. If I do lose a lot I will move them all (AAARUGHHH). If things stabilize I guess I'll be ok.

Hi betterbloom - I have heard people mention someone in Ky who specialies in rebloomers. I may just give her iris a go.

Thanks again all - you have really helped!

if your beds are close to the road you might be geting salt and what ever else they use on the roads paul

I'm in TN too and here because of our humidity we do have to watch for iris rot that strikes predominately in the spring. If I catch it in time, I just pull the dirt around the rhizome away and scrape out the rotten part. Other than letting the air get to the iris rhizome, I don't treat iris rot with anything. If caught before too much of the rhizome has rotted away, they usually recover for me on their own with this method. Air circulation and sunshine seems to be the best cure for iris rot.

I think cathysplants has hit it on the nose. Iris do NOT like wet or muggy conditions - they need to stay dry on well drained soil with good circulation and sun. Little water is better than too much.

Sorry, Lily, but I can't recommend specific fungicides because I don't use them myself (not safe around my 4-legged family). I do know that Daconil is commonly used for leaf spot, and I'm sure any garden center could supply you with other fungicides, as well.

Laurie

Thanks again everyone. Yes, I suppose salt could be a problem phicks. I'll have to watch and see what happens.

cathysplants, your advice sounds great to me! I hope the rot clears up on its own. I'm gad I added so much sand too.

Thanks Steve - if this area doesn't work out for tall beardeds I might just turn it into a japanese louisianna bed. Every fall seems to bring with it big changes made in the garden lol.

Thanks again Laurief. I will take your advice.

Lilyfantn
Leaf Spot can be treated with just about any fungicide that is effective against this disease ( see your local garden center) usually applied early growing season but you can trim and apply now.

For Rot prevention Raised beds, add pea gravel if soil is too heavy along with your compost and sand. pH is a big this with rot and adding lime before the wet season really gets going can make a difference. giving your iris and allowing air flow also helps prevent rot as the leaves dry out better. There is also a possibility of grubs. Not just Iris borers but white grub, wireworms and other parasites that can be drawn to iris. Merit which is in Bayer Season long grub control takes care of most of these. Wireworms can be stubborn and you may need Triazicide which I use with the Bayer

Some Rot Treatments: As early as this rot is you might also want to try, do not laugh, listerine 1:1 and pour it over the rhizome after you pull infected leaves and scrape away any mush (use glove when you are doing this as this stuff is nasty). You can also try comet or other with bleach after cleaning I have used both and both are effective, listerine is just easier for me.


Hope this helps
Anita

When/if I see rot, I scrape out all the rot with a teaspoon till the rhizome looks good and clean, like a cut up raw potato. Then I rub comet/ajax well into the place where I've cut. Depending on the time of year. If pre bloom time, I leave the iris in the ground so hopefully it will bloom. If after bloomtime, I dig it up, doctor it and replant somewhere else. I don't use fungicides. Space and air are really important for iris.

Up here in Manitoba I always plant new rhz. so thy face the sun. They love to bake in the summer. I'm talking about bearded iris here, siberians and others are treated differently.

inanda

Oh thankee thankee thankee all! what great advice! I have started already. You guys are all super! I stopped by Lowe's on my way home from work and got some Daconil. I sprayed all the beardeds when I got home. After dinner I went out and trimmed off all of the leaf spot. Tomorrow after work I will go back out and do the teaspoon scraping comet cleanser thing. I don't know if its my imagination, but they look a whole lot better already. (at least I feel a whole lot better lol)

I will remember to do the lime application next February. This year I sprinkled the beds with Cooley's spring mix which I mixed in with bone meal and some super phosphate. last fall I did the same thing except with Cooley's fall mixture.

We just had quite a bit of rain so hopefully things will drying up again.

Again, I can't thank you guys enough.

You want the rain to get the granular things you've sprinkled into the ground. So be happy about the rain. Just not too much rain.

Inanda - good luck. Am sure everything will be fine.

Lily - when you spray the daconil next time you need to use a stickative or at least some dish soap in the spray or the stuff just rolls off the shiny leaves. You are supposed to retreat every 7-10 days alternating another fungicide. This is after you get rid of affected leaves. I can't remember the name of the other fungicide but I'll get it for you tomorrow when I go to the shed. The real trick is to start spraying early so you don't end up having to do all the work of getting rid of sick leaves. The spot won't hurt your iris supposedly though. It just makes them ugly.

I went out to the shed. I alternate Ortho Disease Control with Lily Miller Disease Control (with Daconil). The Ortho has a different fungicide. I spray three weeks in a row early in the season and then every other week unless there is activity. Needless to say, leaf spot is a HUGE problem here.

Thanks Doss! I got more daconil today and will look for the Ortho too. Everything is on hold now as we are just starting a long cold snap. :-< It is supposed to go down to l9 in the next few days. When things get back to normal I will continue. On the bright side, that should discourage the already present aphids lol.

Wow - I'm surprised to hear you also have a leaf spot problem in Ca. I thought it was dry enough there to be negligible.

It would be dry enough if we didn't have to irrigate. If we didn't have very warm days followed by very cool nights it would help too. Mine are all on a sprinkler system and that's part of the problem but I can't water a perennial garden with a drip system. Tried that too. We are very prone to mildew on our roses too even without sprinkling.