Fill your adjustable hose end sprayer with milk, set the dilution to 3 ounces per gallon, and hose it down. Do that every other week. I would not expect immediate results (typical for organic solutions), but I would expect results. Give it 21 full days to cure it.

dchall,

Could you not have written in a few minutes earlier so that I would not have to write an essay on how I solved my problem the hard way??? LOL!! :)

Hollyhocks growing in soils too rich get rust much easier than hollyhocks growing in soils that are leaner and meaner. There are hollyhocks growing wild in some open soil between a parking lot and an alley that get no attention from anyone, including water. These grow profusely with lots of flowers and no rust even though within 3 blocks someone has some, maybe seeded from these, that have rust every year. Much better soil?
The self seeded hollyhocks in one planting bed at the church grow abudantly with no rust but around the corner some self seeded hollyhocks, richer soil, get that rust.
Just my observations.

Hollyhocks we gave the corn meal treatment to last year have no rust this year; the others do. I plan to repeat this experiment.

On the other hand Kimm I think there's something in what you say. People here tell me their grandmothers always had hollyhocks growing beside the house, never fertilized and never heard of rust. I planted hollyhocks in soil amended with compost and fertilized yearly and the rust is terrible. The same people ask me for hollyhock seed or plants and I hesitate to give them any for fear they will get rusty.

how do you make a soil less rich if you hae rich soil where your hh grows?

paulns

FWIW

I have one, old fashioned single blossom that is a tad over 30 years old. It gets a shovel full of 20+ year old horsemanure every year.. No rust

Byron

The type of soil doesn't really matter. I do have some growing in not so good soil. Quite well, I might add.

The problem is when the fungus is present on (in?) the soil, or if you've purchased one with the spores or if growing from seed, have used seeds infected with spores.

why not 1:1 ratio of water:milk?

thank you for all your information. It is pretty bad on all 3 plants and I may try the milk solution and cornmeal in the late summer too. I really don't want to have to pull them out just yet. I've been disposing of the dead leaves and ones I've cut off int he garbage and not composting so as not to spread it to others in the family.

Thanx again
Keri

Keri,
As I began posting three years ago, cornmeal will control hollyhock rust. Now that it is present in your soil you must begin treatment early every spring. The minute that you see signs of the first sprouts, dust the area with cornmeal and repeat every two weeks throughout the growing season. I was not aware that milk also controlled hollyhock rust. Would like to hear more from those who have tried the milk treatment.

Kimm,
That would explain why my HHs have had no rust this year. The first year I planted them I amended the soil like crazy. When they finally bloomed, they got rust. This year I haven't had time to amend the soil as my veggie beds have grown larger and needed more care. No rust! Now it must be noted too that we've had a much drier season and I've also been careful of cleaning up the dead leaves and blooms. But I have seen various plants grow stronger when they have to work at it a bit. Kind of like people. . .

If Nandina says corn meal will work, then it will work. I don't grow hollyhocks, but when I see 'rust,' I just assume that corn meal will be ineffective (as it is in the turf disease of the same name). Compost and corn meal should be on the surface of every garden soil IMHO.

Hollyhock rust does not exist in soil, it completes it life cycle on plant parts only. It may overwinter in the spore stage on plant debris left on top of the soil, but this rust is not "present in soil" as such. This rust is spread primarily from wind blown spores. The link explains it well. Along with proper watering and sanitation, wettable sulfur is an effective fungicide for this disease if applied at the right times.

Here is a link that might be useful: CSU

Another suggestion I read in a gardening book is to accept the rust and grow a different, lower, later perennial in front of the hollyhocks to hide the wreckage.

Wow, I'm learning a lot from this post. I have Hollyhocks this year and watched as my plant went from a bushy, full, healthy plant at the back of the border to almost leafless (because I had to pluck them all off).

I read something about the weed Mallow being a spreader of the fungus...and I have have a lot of that (I now notice)in the spot I'm growing the HHs. The weed has some serious roots (it is impossible for me to dig it up and get it all because I would probably have to get a front-loader and dig up a trench in my yard).
Does cornmeal work as an end-of-the-season treatment too (i.e. amending the soil with it in the fall after cleaning up the bed)?

Thanks all...I have been very disappointed to find a bad case of rust on HHs that were winter sown in 2004 and just coming into bloom now. The foliage was looking fine, so not sure when it started showing signs of rust, as I have been distracted by other areas of the yard needing attention. One plant nearest the downspout against the house, is just covered. I think I would like to just pull them all out of there, but then it is going to leave a very large hole in a border, that I have no idea what I could add this late in the season that wouldn't take all summer to fill in.

BTW, would there be any problem growing delphinium in the same place you had a HH that had rust on it?

One more question...if the rust can contaminate the seed, then where can you possibly find seed that is not contaminated, if most people have it?

:-)

rouge plants around your downspout and design a system to manage water run-off:either a "french drain"or rainwater collecting barrels for reuse...
In my view,shifting patterns of precipitation,heat,drought, prolonged waterlogged soils and so forth are some of the issues that will influence how we view wintering over of pathogens, what we grow and where we obtain seeds....Mother Nature is testing our "cleverness"...

Move to Mid west where it is not as wet as Northeast :-)

Now Byron, be nice. We like our Northeast places... well, maybe this year with all the rain we might consider moving... but then again, maybe not. :)

Prairiemoon,

I get HH seeds from plants which I see have no rust which friends or others grow. In terms of commercial seeds, I won't plant the new HH in the gardens for a year, hoping that it will show whether or not it has rust during that time - which they usually do.

Planting Delphs in your old HH area won't be a problem.

tiffy..

Thanks very much for answering my two questions. :-)
So when it is time to trade seeds, do you trade your Hollyhock seeds? I don't have any friends with Hollyhocks, rusty or not. [g]

Still not moving from the Northeast either. :-)

I'm reviving this old thread because my HH has rust and I didn't know what caused it or how to treat it. I'm still confused a bit on the exact cause, as it sounds like some think over watering contributes, plus the fungus and apparently too rich of soil.

I just removed all the effected leaves, did the cornmeal thing, and wonder now if all of my seedlings in pots nearby should be moved to another area of my yard to keep them away from the one with rust?

This was a gorgeous hollyhock before the rust, and I looked up this topic hoping to glean information. I found a lot, but would still appreciate these answers.

-Susan

I have been battling with hollyhock rust lately and it makes me wonder... years ago I took on a garden project where you couldn't stop the hollyhocks from growing in a crushed stone walkway lined with landscaping fabric, I would dig them out as fast as i could an they would always come back!!! Not that I didn't love them, but they were literally in the middle of a walkway, anyway, they were always beautiful with no signs of rust, no place for the spores to harbor maybe???

I am new to the forum and would like to thank all of you with so much knowledge. I have frequented this site dozens of times when trying to find an organic solution to my plant problems or just needed a question answered. I am new to outdoor gardening, I enjoy it greatly. When my Holly Hocks started showing yellow clusters on the bottom leaves, I assumed I had an insect problem, so I came straight to this forum to check. Nope, not insects. Who would have thought corn meal would be a solution. I will remember to put the corn meal in my bed next year. They were doing just fine until we had rain, rain and more rain. I do believe we have set a record with rain fall this year and it has not been good for any of my flowers other than huge bed of Lilly, they seem to like it. Thank you everyone for all the help. I would like to post a photo soon of some beautiful flowers I planted from seed, I planted so many seeds I do not remember what they are, but I adore them and want to plant a lot more of them next year, perhaps someone can identify them for me.

OK how much cornmeal is required for one plant ??????

Approximately how much cornmeal? Thank You

Hollyhock rust is caused by a fungus that overwinters on infected plant parts, which includes members of he mallow family. The spores that cause the infection do not live in the soil but travel through the air. I have noticed that Hollyhocks growing in a good healthy soil have rust more often than Hollyhocks growing in leaner, meaner soils.

Whether cornmeal has any real affect on plant diseases remains to be seen. Although the original research at Texas A & M appeared to have some anti fungal property the same researchers could not replicate that in future research and no one else has been able to either.

How much corn meal is needed to stop Hollyhock rust? Enough to stop it which is an unknown.

kimmq is kimmsr

Hello! I'm new. Just discovered the other day the dread orange spots on my hollyhock plants. Eeek! It began on one of the five plants, seemingly overnight, after a watering the previous evening. Bottom leaves suddenly spotty and wilty. God, the day before all plants were robust and green! I mean, one of the plants already about 7' tall, etc. After discovering this yesterday, I pulled off a ton of affected leaves on all five plants, dying a little death with each pluck. There are other leaves, higher, with a "hint" of rust on them, that I couldn't bring myself to pull off, because, well, you gotta have some leaves on the stalks, don't ya'...? (Sorry, to sound so wounded, but I had planted these two years ago, watched them go crazy with foliage the first year, and then, finally, this year see them get vertical and finally produce some buds, etc. -- they seemed "on the verge" of doing the hollyhock thing, maybe spectacularly.)

Anyway, what can I do NOW? The plants may be too close together, but I hate to dig any of them up, illogical as that may seem at this point. Certainly, the spacing hadn't seemed to interfere with their growth. And today, after yesterday's de-leafing, they still "look" promising. I'm in Tennessee, by the way. Thanks for putting up with this weepy indulgence.

I destroyed all but one or two plants. I put some corn meal around my plants shortly after my first post. I can't see that it helped anything as of yet. Going to try some wettable sulfur next.

How Should the wettable sulfur be applied? Sprayed or dusted?