Protecting Iris from Voles

Please, I'm looking for some advice. The vole population in my gardens is unbelievable and I've fought a major battle with them. I have lots of experience protecting my Hostas, shrubs and bulbs from those beasties, but not Iris.

This year (for the first time) I had a number of established Iris not return and I'm assuming it's the voles. The shape and growth patterns of the Rhizomes makes them somewhat unsuitable for hardware cloth pots. What does everyone do? I will miss my lovelies and don't want to lose more. Thank you.

I had major damage this year from voles but they didn't bother the Iris--mostly just my daylilies. They eat all the roots and almost killed everything. Did you use some kind of a killer on them?

hugeposiepatch, My gosh, I'd heard that they don't eat daylilies. OH NO!!!! I've seen them hide under my DL, but they've never damaged any. I used several poisons, but the #'s killed never kept up with the #'s born. They quickly learn to avoid the poisons, so you have to keep changing types. Unfortunately, putting poison out also kills their predators.

Someone else said to try mousetraps. She said it was the only way to get them. Use slices of apples for bait. I cleaned my gardens up--I had groundcovers around my daylilies--I took them out. I don't seem to have as many voles anymore but I am still watching.

hughposiepatch, I tried that last month. First with pnutbutter, then apples. 40 traps were all sprung & food gone, but no dead critters!!

Yes, I have removed all ground covers too. They are there!!!

A friend stick poisen in PCB pipes so feral cats can't get at it. They used to sue traps with peanut butter in the holes but obviously gave that up.

My neighbor has a sewer ditch along side her front yard. Last year when I would walk by it, you could see the voles running by it. I was trying to kill the grass in my own yard-so I laid plastic and then covered it up with mulch. I think that is how I got so many of the voles in my yard. When spring came this year--there were tunnels everywhere in my gardens--mostly around my newly planted daylilies from last year. I was sick--I hang out in my gardens all summer--they are what I live for. Any ideas to get rid of the voles--then I am willing to try. Anything new I plant now--limestone goes into the hole--I read somewhere that voles don't like small sharp stones, so I am trying that. I hope it works. I didn't try the mouse traps but was thinking about it. I also heard that oyster shells would work if mixed in with the planting holes. I may try that too.

~~Sandy~~

The owner of a local garden center here advocates a repellant that contains castor oil. http://www.allrepellents.com/category/vole-repellent/
I think it's another brand he sells, but he states clearly in a recent weekly column that of the three or four popular deterrents, castor oil is the most effective. http://forums.gardenweb.com/forums/load/hosta/msg0912371024956.html

Steve, I hate to be a spoil sport, but I used many castor oil based products, including a complete drench of the entire property, not just beds. It was not effective at all. So I did it again, 3 times, with 3 different castor oil products. Nada.

The gravel products helped a lot with the bulbs. But the Iris Rhizomes are both above and below ground and that is a problem. What are other Iris growers doing? I never noticed them bothering Iris before. I'm assuming that's what killed my Iris. DO VOLES EAT IRIS????

They eat the roots, so you lose the rest of the plant.

I've never had problems with voles bothering my Iris or Daylilies, but they sure did a number on my Lilies and Tulips. They've mostly been a problem for me when I have mole problems- they use the tunnels to get to the bulbs. I tried Castor oil products with success, but I think it only works for moles, and needs to be reapplied after rains. The best line of defense for me has been cats.

We don't have moles, so no tunnels. They also like to run on top of the ground under the snow. We do have chipmunks, time for DH to get the bottle of fox urine & put it down their holes.

stormyla. EEEK new info!!!
Thinking as an engineer, now, instead of a plant person: maybe you could rent a Ditch Witch, dig 3 ft trenches criss-crossing your property and separating it into a number of isolated squares. Fill the ditches with the very sharp gravel they hate. Then, one at a time you could dig each of the squares out. Make sure it was free of critters, replace the dirt and ... oh, never mind.

I wonder if they like scotch bonnet peppers? Diatomaceous earth? Cats?

I was at a hosta farm today,, and each and every plant he had ,,,had a plant in a plastic pot, and sticking up out of the ground about 2",,he said it was due to voles...,,he had hundreds of varities,,very impressive! good luck!

D-lilly, All of my hosta and shrubs are in hardware cloth cages and my bulbs are all planted with Permatil. It's the odd shape and the "walking" growth patterns of the Iris Rhizomes that presents the challenge. Also, it's more complicated because part of the Rhizome is above the soil. This is the first year that they bothered my Iris and whole sections are gone. I have not noticed any damage to, or missing Dayliies.

Steve, I applied Diatomacious Earth to my beds twice last summer. It pretty much wiped out the grasshopper and ant popuations which sent the frogs onto greener pastures and the grasshoppers around to the back of my house!!

Hughposiespatch, you can also use chicken grit.

I only had 7 Japanese irises, and now have only 5. There is actually a hole in the ground where they used to be. I am so mad. Was expecting them to bloom for the first time this year and now they are totally gone. I think I am going to try the mouse traps and see what I catch, as there are holes all over my garden, so not sure if moles, voles, mice or chipmunks. They also cut all my clematis stems right at the base of the plants. Looks like someone took scissors and just cut them all off. At least new shoots are coming up, but the irises are totally gone. I like the suggestion from Steve812 about the Ditch Witch. LOL.

Mshadow, moles generally make mounds of dirt around the openings to their runs Voles just make holes. Voles will use the tunnels already dug by moles and ground hogs, or will dig their own. Voles will migrate from one spot to another in your lawn & beds.
Voles hate to be out in the open. Don't leave any debris for them to hide under. Don't plant any dense ground covers. Do not use thick mulch. Here's some good reading:

http://voles.com/

I had a problem with some sort of subterranean mammal eating my iris and rose foliage above ground. Almost every day there was new evidence of attack - usually new leaves. Bought and applied "Repels All" granules http://www.arbico-organics.com/1287601.html Saturday. Using the garden hose, I flushed a considerable amount - maybe a cup - down into the almost endless 2" diameter burrow. Have looked for but not found any further damage in three days. It's a start. Only downside so far is that now the bottoms of my shoes reek of garlic and peppermint.

I am going to have to try that Repels All on my gophers -- which I am willing to bet is what you have. They have been eating my iris like crazy though everyone says they don't. I have trapped them from time to time, so I know it is gophers. That could be your problem, too.

Someone was saying on the Hosta forum that peppermint oil was very effective against rodents.

I am just about ready to give up gardening. I don't know what else to do. I got new plants this year and now the voles (that I thought were gone) are eating all my new white root growth. What else can I Do???????????????

Try wafferin in side PCB pipe to keep it away from pets.

Is warfarin (rat poison and also a blood thinner for people with heart problems...) available at home centers? How is it labelled?

I don't use it as don't have the problem. I was passing on information from a person who does. I'm sure it is available, name? ask at the desk.

Yes, you can buy it at any home depot. Look for things called all weather bait type rat and mouse killer. It comes in little green chunks.

That rat and mouse killer stuff worked for a while but now they (the voles) won't eat it just all my new white root growth. I am trying crushed oyster shells, limestone and screen from windows. I hope this helps. If not, I have this big yard sale in July. I sale all of my plants off.

Hughposiepatch, I have used hundreds of $ worth of rodent poisons. Remik, Tomcat, Warfarin yada yada. They all work for a few days, but you are also killing their predators. After about a week the voles get wise and then won't touch the poison du jour. You have to keep rotating them and you are only reducing, not eliminating the problem. They mate every 2 weeks and have as many as 13 beasts per litter.

The only ways to protect your plants are to plant them in hardware cloth pots with chicken grit or permatil mixed in the top 2 inches of soil. Leave at least 2" of the pot above ground. Then dig a 4" wide & 4" deep moat around the pot & fill it with the grit. Do Not mulch over the grit.

If you don't want to make pots, then plant your plants in 3" thick of Permatil then backfill with dirt and top with Permatil. Dig the same type of moat & fill around the plant. Do not use mulch or ground covers around the plants.

This may sound weird, but do you notice a certain color disappear first? It seems that my pink tulips and daylillies are the first to go. And I have a yellow and white iris that hasn't bloomed for years. I'm thinking the moles are eating them. Anyone else notice this?

The voles got hungry after three days of smelling repellants, and made a b-line for the iris patch. I was transplanting a rose this morning and I heard a munching noise coming from a nearby iris. I saw the foliage vibrating. But nothing was eating it from above ground. Spent a few hours reading about traps and poisons. Trouble is, I live at the edge of a national forest. If I use traps, I'm going to be moving voles for the rest of my life. Not how I want to spend my time. I guess putting protective wire mesh/ pots around all my fleshy root plants and using sharp grit is the only solution...

Thanks for the advice stormyla.

Good luck Steve. It certainly worked with my Hosta, shrubs and bulbs. But the Iris roots are tough, because they keep growing sideways across the top of the earth. I'm afraid that a wire pot with raw edges on top of the earth would shred the new surface Rhizome growth. They certainly shred my fingers when weeding.

Has anyone grown iris in wire pots?

Smashedcactus, No, I don't grow pink flowers. LOL But I did notice that "Ghost Ferns" disappear immediately!!!!

stormyla, Will the voles really eat every plant in the garden? Are there plants they don't like?

Thanks for all the info though! I am going to have to do something if I really want to garden. I have been gardening for over 20 years and never had this kind of problem before.

hughposiepatch, there are more plants that they don't eat than those they do.

They love hosta, bulbs and rhizomes, corms. They seem to go for ferns, corydalis and astilbe. They knaw many shrubs, Rhodos, Laurels, Azaleas, Dogwood, Conifers.

Gosh! Is there anything left???????????

I read somewhere that they didn't like Hellebores? I hope that is true.

Thanks for helping me out!

Sandy

More Pacific Northwest Vole discussion:

http://davesgarden.com/community/forums/t/986953

Kathy

Remember that if your voles eat the poisons and the cats catch them before they die, the cats will also be at risk.

I have vole issues, as well, but I don't have daylilies or many iris, so I haven't encountered that specific problem yet. I have cats outside, and while they catch voles, they aren't able to keep the population down, I don't think.

Garlic is supposed to help. The slugs (and we have big ones here) seem to leave the Hellebores and the Garlic and Onions alone. I'm going to strart using those liberally.

With some exceptions, what I've heard on various threads (and there is much discussion going on about this) is that you have to do multiple things: use traps in PVC pipe and clean and bait them daily, plant Garlic and Onions and othe strong-smelling plants, get rid of your Moles (because Voles use their holes a lot), and let predators help (snakes, cats, ferrets).

I suspect that, by the time we feel we have a problem, the populations are large enough that it's going to take a few years from us to get the vole populations back down again.

Kathy

Katie, They also use Groundhog dens and tunnels.

Thought you all might enjoy this old thread.

http://davesgarden.com/community/forums/t/915474/

I would think that a live blacksnake would be more useful.

I would pay somebody for snakes. I have seen only a few on my property, but I think they'd be good vole catchers.

Great thread, stormyla - I may just try it. Can't hurt.

The voles continue to nibble on my iris and roses. And every day they devour another border pink - lock stock & barrel. And they have nibbled two large artichoke plants to the ground. The good news is that I have more roses and iris than they can eat at once: probably the total growth rate of my decoratives outstrips their ability to eat them by a factor of ten or twenty. But I still lose plants.

Regarding controls, I guess I've changed my mind again. I don't think I'm really going to put all of my decorative plants in metal mesh enclosures. I certainly cannot protect foliage that way.

I wonder,
1) Are there snakes that pose no risk to humans but do pose great risk to voles and rats? Perhaps a nice boa? How would one acquire such a critter?
And
2) Would a ferret be better? Where might one find a ferret who has a taste for vole? Do they pose other dangers?