Garden Basics with Farmer Fred

242 Biochar. Roof Rats.

December 02, 2022 Fred Hoffman Season 3 Episode 242
Garden Basics with Farmer Fred
242 Biochar. Roof Rats.
Show Notes Transcript Chapter Markers

You may have heard the term, “biochar”, being used in gardening circles. What exactly is “biochar”? And why is it being added to more and more soil products that you could find at the nursery? We will find out. Also, Roof Rats! They’re not just for your attic anymore. If conditions are right, they will invade your fruit and nut plants outdoors, and in some instances, move out there. We have control tips for roof rats, and how they differ from other rodents you might find in your garden.

We’re podcasting from Barking Dog Studios here in the beautiful Abutilon Jungle in Suburban Purgatory. It’s the Garden Basics with Farmer Fred podcast, brought to you today by Smart Pots and Dave Wilson Nursery. Let’s go!

Previous episodes, show notes, links, product information, and transcripts at the home site for Garden Basics with Farmer Fred, GardenBasics.net. Transcripts and episode chapters also available at Buzzsprout

Pictured: Rat Gnawing on Prickly Pear Fruit

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Biochar Info
Biochar
International Biochar Initiative
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GB 242 TRANSCRIPT Biochar. Roof Rats.

[00:00:00] 

Farmer Fred: 

Garden Basics with Farmer Fred is brought to you by Smart Pots, the original lightweight, long lasting fabric plant container. It's made in the USA. Visit SmartPots.com slash Fred for more information and a special discount, that's SmartPots.com/Fred.

Welcome to the Garden Basics with Farmer Fred podcast. If you're just a beginning gardener or you want good gardening information, you've come to the right spot.


 You may have heard the term, “biochar”, being used in gardening circles. What exactly is “biochar”? And why is it being added to more and more soil products that you could find at the nursery? We will find out. Also, Roof Rats! They’re not just for your attic anymore. If conditions are right, they will invade your fruit and nut plants outdoors, and in some instances, move out there. We have control tips for roof rats, and how they differ from other rodents you might find in your garden.


We’re podcasting from Barking Dog Studios here in the beautiful Abutilon Jungle in Suburban Purgatory. It’s the Garden Basics with Farmer Fred podcast, brought to you today by Smart Pots and Dave Wilson Nursery. Let’s go!


 Have you heard about Biochar? We're gonna be talking about a soil amendment that may save you a lot of money when it comes to fertilizer, as well as improving the soil. What is biochar? How long has it been around? Let's talk with Milt McGiffen. He is an Extension specialist down at UC Riverside, who has been studying biochar for a long time.  And Milt, let's talk about some biochar basics. What exactly is biochar? 

[00:01:43] 

Milt McGiffen:

That's a good question. Biochar is produced by burning something that's high on carbon. Usually some waste product only. You don't exactly burn it. You make it into a charcoal. So when you make charcoal,  if you burn a fire, you give it plenty of oxygen so that you get a lot of heat back and it burns quickly. 

When you do that though, the fire will eventually go all the way to ash and all that carbon that's in it goes off into the air, which is carbon dioxide. One trick to making charcoal is you starve it of oxygen. So when you do that, you're gonna give it some heat and you might do a little bit of burning and get the heat up, but you start it of oxygen and you get a chemical decomposition of it so that you hopefully end up with something that's pretty much pure carbon. 

So if you're talking about what people think of as pure biochar, You, what they would give you as a description of it is basically pure carbon. So it's gonna be sheets and sheets of carbon, very similar to graphite  structure.

[00:02:36] 

Farmer Fred: 

And for the untrained eye, they might think it's charcoal.  

[00:02:41] 

Milt McGiffen:

 Yeah, sure. It's a type of char.  Not all charcoal is biochar. The biochar is a type of charcoal. That's exactly right. 

[00:02:48] 

Farmer Fred: 

 So basically this is slow cooked dead trees, if you will.  

[00:02:51] 

Milt McGiffen: 

Pretty much, yeah. They make from sewage. They make it from all sorts of carbon. It's basically, you just need something that's got a lot of carbon in it. 

And then you need to go through the process we call pyrosis, which is what I just described, where you're heating something with no, or very little oxygen in it.

[00:03:04] 

]Farmer Fred: 

Biochar has been around for centuries. How did they do it? Way back when?

[00:03:09] 

Milt McGiffen: 

 Probably Mother Nature's been making biochar for a long time. We just didn't see it that way. And if you think about it, fire's a big part of our ecosystem out here in the west. The Midwest has very deep black rich soils. Some of that's because they had grassland growing there, but some of that's because the grassland burned and it went into a form of carbon that's persisted in the soil. 

So biochar itself has probably been around a long time. But then you invent the airplane and people start flying over the Amazon and you realize it's not this uniform sheet of green, that there's some places that are a lot darker  than others. And when they saw that, they then sent in some agronomists into the jungle and they started digging soil pits, you know what? Soil scientists look at the soil. The areas where they were dark green. You could see that, that they're black and that the soil is black for six feet down. or, If you dig it in the other places where you didn't have this dark, you got a typical tropical soil where it just is a very thin layer of top soil, and then it's, very light colored on down. 

So something that happened in those areas of the dark green. The natives had done something a long time ago, and the native peoples, what they'd done was they varied, they did slash and burn agriculture. So  you slash down the trees, you put 'em in a big pile. And you try to burn 'em. 

It doesn't burn completely because they're, it's wet in the Amazon to begin with and you've got these green trees. So you basically went into pyrolysis with a lot of that. You made a lot of charcoal, and then they just incorporated that back into the soil. The natives, then the Native Americans then died off because of the diseases, but they left behind that charcoal. 

And so those areas became overgrown with vegetation as their want to do in the tropics and the vegetation flourished in those particular places. So then when the soil scientists went down and dug in, what they discovered was that these were manmade, obviously had a lot of charcoal in it, and it was something that the natives had done, maybe 500 years or more maybe even thousands of years before, they had dug these pits to check it out. 

 So whatever the natives did, It persisted for a long time and it really increased plant productivity, and that's basically the origin story most people give for biochar. It turns out though, that a lot of cultures have used charcoal in agriculture for a long time. There's even  a US publication, US government publication, on using charcoal in agriculture, and. All sorts of things. The Japanese have used it for a long time. It's been around, it's been used. We may not have understood it all that well, but we did have it.

[00:05:40] 

Farmer Fred: 

As you said, the biochar improves the soil. It doesn't break down like compost or commercial fertilizers will. 
 So from the aspect of the farmer who's looking to save money, there's a money saving benefit right there. You're going to have a very nutritious soil at less cost.  

[00:05:59] 

Milt McGiffen: 

Yeah. It should persist for years and years after that, once you put it in. 

[00:06:05] 

Farmer Fred: 

What sort of soils would benefit most from an application of biochar? I would think that it would raise pH, so it would be most beneficial on a very acidic soil.  

[00:06:14]

 Milt McGiffen: 

Yeah, the most obvious things in acidic soil. Now, biochar has evolved over time. At one time it was, there really wasn't much post process, you would just make charcoal and that was it. And they basically made charcoal. 

Now there's a lot of post-processing with it. So you can get biochar that's neutral or pH adjusted or what have you. And so for our soils, you can get around that. But as far as soil types here that are gonna improve, be improved by it, I would think a lot of ours would improve simply because they're low in carbon. 

 That's always been a thing with us and trying to raise the carbon content's difficult because most of the things we put in the soil don't persist more than a few months cause it's warm and we water the soil and they just get chew up by the microbes 

[00:06:54] 

Farmer Fred: We're talking to Mil McGiffen, extension specialist at UC Riverside about the benefits of biochar. 
But there may be some drawbacks when we come back. The possible problems with using biochar coming up. 

[00:07:17] 

Farmer Fred

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[00:09:17] 

Farmer Fred

We're talking with Mil McGiffen. He's an extension specialist at UC Riverside. He is a specialist on biochar. He's been talking about the benefits of biochar, but there is the possibility of some drawbacks, including the translocation of harmful gases to plant roots.  

[00:09:33] 

Milt McGiffen: 

There's been different studies about gas evolution by biochar, but I don't know of anything that's quite like what you described. You must be referring to a particular study. So what study is it you must have read?  


Farmer Fred: 

The study I did take a look at before we started our chat was from the University of Illinois-Urbana Champagne, where they did a study called “Using Biochar as a soil amendment for sustainable agriculture”. 

 And they point out in their summary that yes, there is a lot of value to using biochar, especially as far as saving money on fertilizers and improving the soil. But there may be, and they weren't positive on this, but there may be some chemical contaminants that biochar usually contains. Small amounts of phytoxic and potentially carcinogenic organic compounds such as PAHs, which I believe are polycyclic aromatic hydrocarbons. Therefore Full environmental risk assessment is necessary before widespread adoption for biochar as a soil amendment can be recommended according to their report. 

[00:10:37] 

Milt McGiffen: 

That's the only time I've ever heard somebody say you need a full scale risk assessment  of biochar. The truth is, we're heading that way with fertilizers in general anyway. 

[00:10:46] You could get certain contaminants depending on what you make biochar from and how you're making it. Generally speaking, it's not been much of a problem. Like I said, if you do get biochar from someone, it's not gonna be pure carbon or what we would think of as pure biochar. By law in the state of California, if you wanna sell, you wanna put on your bag that this is biochar, you wanna sell it to somebody that way, it's gotta be at least 60% carbon. 

 So then technically the rest of that could be ash, and the ash could have a variety of different things in it. It would really  mostly depend on what the feed stock was and then how you made it. The ash also could be good. Potassium. You do the potash test. The reason it's called potash test is it goes back to the old days when they got potash from wood ash, so that extra ash in there could add a lot of potassium to your soil, but it wouldn't be biochar. 

So you might have those problems, but beyond That's really out there as far as it having a toxic, an effect like that. You could make it in theory from feed stocks where maybe you had a lot of painted wood or something like that, and I could see you would have a problem, but otherwise we really haven't seen that. 

[00:11:51] 

Farmer Fred: 

One source of biochar that has a lot of promise are the millions of dead trees we now have in California's mountains due to the drought. And of course farmers are always churning up old orchards to plant new orchards and vineyards. So there's a lot of potential as far as a source for the biochar, isn't there? 

[00:12:09] 

Milt McGiffen: 

Yeah. It's a nice marriage because we don't know what we're gonna do with all this excess wood. And if you drive through the Central Valley these days, you can see there's places where there's acres of old trees, Piled up in just big piles. and you can't burn it. burning's very restricted in the valley these days. 

So what you're gonna do with this wastewood's a good question. And then you have essentially a Tinder box up there in the Sierras because you have many dead trees from the years of drought. They're hard to get to. They can't really lumber them out, apparently they're not good for lumber, or at least the cost to take 'em out is prohibitive. 

So the idea of turning all that into biochar is very attractive as well. And then there's the other thing that most, any of the other methods of doing something with wood, you're eventually, it's eventually gonna end up as being carbon dioxide, and that of course contributes to global warming. So with biochar, it's a way of converting the wood into something that would actually help the soil and also sequester carbon for a long time and take it out of the atmosphere. 

[00:13:04] 

Farmer Fred: 

Using biochar would, of course, be a sustainable practice. Is it an organic practice?

[00:13:11] 

Milt McGiffen: 

Yes.  everything you use the short answer to is it organic or not, is you need to talk to your certifier. Because that's really the person that whoever's certifying your field's gonna make that determination. 

But there are a number of biochars that are registered with OMRI and with the U S D A organics program. So you would want to work it out before you start using it, whether it's acceptable practice, but there are ones that are perfectly fine for use in organics and a lot of organic people I know do use it.  

[00:13:37] 

Farmer Fred:

 Is there much resistance to biochar from the government or the national resources conservation service?  

[00:13:45] 

Milt McGiffen: 

There's a number of people in both of those agencies that are doing things with it. We have a very good person in the governor's office named Mike McGuire, that does a lot of things with biochar. He has been very helpful to us. 

We work with the nrcs people on biochar. They have not given it a ringing endorsement, that would be fair to say. And they've not included in the Healthy Soils program to them. They feel it's still a little too risky. (Studies are currently being funded in California to study it). It hasn't been proven enough to me. It's been used for centuries. It's as uniform as compost is. 
 So to me, I would just rate it pretty much the same as compost. It as far as safety of practice, that it's gonna depend on who's making it and where you get it. But if you have reasonable procedures, it's fine. And we know that it has very good benefits for the soil. So to me it should be included in that group. 
 But it is new for us. We haven't been using it very long. Maybe a decade or so, so I get it, but they have worked with us at different  times.

[00:14:38] 

Farmer Fred: 

 Are you optimistic about the future of biochar?  

[00:14:41] 

Milt McGiffen: 

Yes. And for the simple reason that there's only so many ways you can dispose of organic waste. And when you start doing the math on how you're gonna dispose of this waste, where you're gonna put it. 

 Are you going to contribute to the greenhouse gas problem or are you going to decrease the greenhouse gas problem? Biochar starts looking pretty good. It may be a while, but it does look good and we are seeing people do it. We start seeing people getting the equipment to just do it right on their own farm. 

 If this ever got subsidized, By the government as something to use, maybe subsidize it under greenhouse gas reduction program or something like that. It would really take off. The problem with it is there just isn't a lot of money. That's basically where you are and that's generally true of all the waste products. 

 You don't see a lot of research and other things in the compost either. For that simple reason. There just isn't a base of funding to do it. But when you start doing the math on it logically, what are you gonna do with these waste products? Biochar stands up really well. 

[00:15:40] Farmer Fred: We've been talking with Milt McGiffen, he's an extension specialist at UC Riverside. 
I think we'll call you Dr. Biochar.   

[00:15:47] Milt McGiffen: Geez,  that's lovely.

[00:15:47] 

Farmer Fred:  

He's optimistic about the future of biochar as a soil amendment to decrease fertilizer use, as well as improve the quality of soil. And it has a bright future. 

[00:16:00] 

Milt McGiffen: 

There's a lot of sources for information on biochar, but probably the best clearinghouse for all of them is the International Biochar Initiative. 

So if you just Google IBI or International Biochar Initiative, you'll eventually come to their webpage (https://biochar-international.org). They have a lot of white papers. They review the scientific literature every month. They have experts on there. They do webinars. If you join and become a member, you get access to the webinars, things like other things that other people don't, but there's a lot of free stuff there too. 

So just by doing that, you'll find them. There's a number of other sources on the web and I do a biochar blog, which anybody can join in on. Probably going to IBI is your best one-stop shopping place for information on biochar.  

[00:16:40] 

Farmer Fred:

  Milt McGiffen. Thanks for a few minutes of your time.  

[00:16:44] 

Milt McGiffen: My pleasure. 

[00:16:50] 

Farmer Fred: 

It’s harvest time for one of my favorite fruits to grow, the Japanese persimmon. This versatile, beautiful, nutritious and tasty fruit makes for a great holiday gift as well. In Friday’s Beyond the Garden Basics newsletter, Warren Roberts of the UC Davis Arboretum tells us all about the Japanese and American persimmons. In the newsletter, we have cultivation tips as well as a recipe for drying persimmons, which make for an outstanding gift.

For current newsletter subscribers, look for the Persimmon Primer podcast and newsletter, in the Friday, Dec. 2 edition of the Beyond the Garden Basics newsletter, it’s in your email. Or, start a subscription, it’s free!  Find the link in today’s show notes or sign up at the newsletter link at our homepage, garden basics dot net.
 

[00:17:44]

Farmer Fred: 

This next chat involves roof rats. And it will be particularly useful for those of you with large yards, or acreage, or even a small farm, in which you have a large orchard. And for those of you suburban dwellers who might have a few citrus trees, well, you know the damage that rats can do to that fruit. But it’s not just the fruit. Roof rats, especially, can girdle your backyard citrus trees, dramatically shortening their lifespan. If your yard is large or your yard is small, and you have roof rats, we have tips, courtesy of University of California’s Ag and Natural Resources farm advisor Rachael Long. We recorded this a few years ago, right after a rainy winter, too. 
 

Farmer Fred: 

A lot of homeowners are getting concerned and asking the question: who's eating my citrus? And it's not just eating the fruit, it's just eating the rinds, which is very unusual. And some of the culprits are being traced back to, include roof rats. Guess what? Roof rats are now in orchards. They're in pistachio and other nut orchards, as well.  They're burrowing and nesting in the ground, chewing on irrigation lines, causing extensive damage and a lot more. We're talking with Rachael Long UC Cooperative Extension Farm Advisor based in Woodland, California. And Rachael, why aren't these roof rats in roofs? What are they doing in the field? How did they get there? 

[00:19:09] 

Rachael Long: 

That's a good question. And so roof rats  just live everywhere. They're very opportunistic and  when they find a food resource, they'll just go for it. So this year in particular has been a really big year. It's the year of the rat , certainly. And and all of these rodents do have cyclical populations. 

 Some years we just do get outbreaks of voles or we get outbreaks of roof rats and other rodents. And I think what happened is last year was such a wet winter and we had tons of weeds that were growing everywhere, producing a lot of seeds, and just provided ideal food resources for that roof rat. 

 And as a result, these other populations just rapidly built up. These roof rats, each female can have three to five litters per year and five to eight young per litter. And so that could be like 40 offspring per rat. And so you can just see that how quickly a couple of rats can build up to hundreds  in a short time. 

[00:20:12] 

Farmer Fred: 

You've been the pest detective on this one, so talk a little bit how you came to the conclusion it was roof rats, because I would imagine that the first suspect would be other rodents or squirrels.

[00:20:22] 

Rachael Long: 

that's what I thought too. So when I got a call to look at a pistachio orchard, I just thought for sure it's gonna be ground squirrels. 
  Because that's usually what it. And I went out there and and just didn't see any ground squirrels. ground squirrels are diurnal, so they're active during the day and I just didn't see any. And when I looked at these holes in the ground they were also way too small for a ground squirrel. 

So ground squirrel holes will be about four inches or more in diameter. And then you usually see a squirrel somewhere. But there was no squirrel, and these holes were about two to three inches in diameter  with a little  pile of nuts around it. And and so I knew that it could not have been deer mice or voles because it was too big for that. 

The deer mice and voles tend to have holes one to two inches in diameter, and these were three and ground squirrels are four. So I just was really scratching my head going, what on earth is this? Because it just was very confusing; it was just somewhere in between. And so I thought about rats. 

 But  I just didn't know what a roof rat would be doing underground, burrowing underground. I did talk to a colleague and she assured me that that roof rats in the country can burrow underground and nest underground. They're above ground and can nest in ground and of course, they’re nocturnal, feeding at night. 
  So that's why I didn't see any.  

[00:21:49] 

Farmer Fred: 

For people who grew up on Bugs Bunny cartoons, they may have thought rabbits might have been the culprit in this situation. But actually rabbits don't dig burrows, do they?  

[00:21:58] 

Rachael Long: 

No, they don't. So that was the question. we actually put out a game camera as well, because we thought maybe we could pick something up. 
 But all we picked up were were rabbits and birds. These roof rats are just sneaky. They're really smart and They hide. And basically if you don't see anything, but you see the damage, then suspect rats. But rabbits, jack rabbits and cottontails, they don't dig and burrow underground. 
 they may just create a little nest like in that and such, but they're not digging and burrowing underground.  

[00:22:29]

 Farmer Fred: 

And then you have the case of citrus trees. And I understand in some situations the roof rats are nesting in the citrus trees, which must be quite a surprise to anybody out there picking fruit.

[00:22:40] 

Rachael Long: 

Wouldn't that be awful to reach in and have a rat jump out at you? So yeah, roof rats are opportunistic and if you have cover year round, like an orange tree, then that can form just the perfect protection for the roof rats during the wintertime. 
 Unlike something like a pistachio orchard  or almonds where the leaves drop in the wintertime, and so they don't have any cover, and that's probably why. Then they'll go underground and burrow and nest underground. But in citrus trees they will nest  in the tree itself. And  what we also see is that not only do they feed on the fruit and typically you'll just find sometimes the hole and then the entire inside of the fruit is eaten. 

And you're just left with a shell. And same with pomegranates. There's been damage by rats and pomegranates, but the worry worrisome thing about rats in the in like orange trees is what they're doing is they're actually stripping the bark off of limbs of trees. And so there's, a sweetness to that. 

 Basically the bark has the sugar conducting part of the of the tree. And the rats are feeding on. But when they strip it they're girdling the tree. And and so you can still have, water conducting up and down but when you take off the park, that, that take, it just basically girdles the tree. 

And a lot of the the trees that rats are nesting and feeding in then have branches that are dying back. And that's a problem because then you lose production for  years.  

[00:24:10] 

Farmer Fred: 

Have you seen any evidence in a mixed planting situation of the roof rats, basically following the crops? 
 When they're done with citrus, they'll move to the next crop that's ripening, be it a nut crop or another fruit.  

[00:24:23] 

Rachael Long: 

Certainly they can move around in fields. And we've seen that. I see that more in something like an alfalfa field where if you disc the field, then the rodents will just, of course they're gonna move out. 

So you're gonna have gophers and voles that are just dispersing everywhere. And I think that you have two things that certainly lead to some natural mortality. When the food resource declines, then the rat population will go down. But I definitely think that they're going to be moving too. 
 I have a colleague that told me he caught in Woodland, that he caught something like 50 rats so far in the last six months. In his in his backyard. And I'm like, Lordy, that's a lot. And so I think they do disperse and once the food is gone, then they'll move somewhere else. 
 

[00:25:12] 

Farmer Fred: The University of California Ag and Natural Resources Department put out a publication about four years ago called, Managing Roof Rats and deer Mice in nut and fruit orchards. What is the difference between a roof rat and a deer?  

[00:25:25] 

Rachael Long: 

So the roof rat is big and much bigger than a than a mouse. 

but they they both can do damage in an orchard. So again, the roof rat, the hole will be about three inches, whereas the deer mouse much smaller, like a house mouse and the holes will be one to two inches in the ground. but they both actually can cause damage. the roof rats really do move up and down trees  and are feeding on the tree and on the fruit. And  then in the ground they're just burrowing underground, not necessarily causing any damage underground. But  the deer mice, they're everywhere too. And they can actually scramble up and down trees, And also feed on  nuts such as almonds, both in the trees and also on the ground. So that kind of surprised me  that actually deer mice can go up and down trees and I'm always surprised by the number of, wildlife that does, move around and go, up and down on, on trees as well. 
 Sometimes I see lizards and trees and I'm like, what are you doing up there? Yeah. So wildlife actually the mice and rodents. So they can move around and certainly cause damage to tree crops and it's rather expensive.  

[00:26:30] 

Farmer Fred: 

 I know there was a study done, I think back in the year 2000, about the cost per acre that deer mice can do, and they pegged it at over $20 per acre to almond orchards in Fresno County due to deer mice damage. 

[00:26:44] 

Rachael Long: 

So they can certainly be damaging. The really critical issue here is that  what I really wanted to let people know about, Is how to identify these different rodents out in our crops so that we can get a jump on them early and control them early before outbreaks occur. 

So that was my intent on putting out a news alert on these, on the rats, was just to say, Hey, this is what the damage looks like. Recognize that. If you can just trap, use snap traps to catch those those rodents and keep them out, keep those populations low because once you get a massive infestation in there, then you can really get a lot of damage, and then control becomes incredibly challenging. 
 So this is just a really a heads up that rodents are out there and just keep an eye on 'em and know how to look for them. Look for the signs of their activity and then control 'em early on to prevent damage. And I always suggest also, barn owl boxes are good to put up for helping to control gophers. and barn owls will also feed on rats, so they can take a lot of rodents and help us out naturally. 
 So that's one suggestion is to put up a barn owl box and use your snap traps and just monitor and know what's out there.

[00:28:00] 

Farmer Fred: 

We have more with UC cooperative Extension Farm Advisor, Rachael Long on how to control roof rats, coming up. 

[00:28:14] 

Farmer Fred: 

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Farmer Fred:

Let's talk about some less toxic methods for controlling roof rats and deer mice. how effective is flooding, if at  
 all?


[00:29:33] 

Rachael Long: 

 Oh, certainly for gophers and for ground squirrels it definitely helps to to suppress the rodents. but now we've really shifted a lot towards the drip irrigation and the subsurface drip. and there you do have rodent problems. Because there you can't flood 'em out. And that's why you have to certainly get in there early and manage 'em and certainly trapping works well.  

[00:30:00] 

Farmer Fred: 

And that  brings up another added cost. If you're fighting a rodent problem, that drip irrigation tubing becomes a target of thirsty rodents, right? 

[00:30:09] 

Rachael Long: 

 Yeah, they do. And in particular sometimes after harvest, like a sunflower seed crop for, that hybrid seed that you're producing, that after harvest and everything is so dry, you do get some cracks in the soil. And  then you have seed out there and you have, voles and deermice and house mice  that are incredibly opportunistic and they just race out and they're feeding on that seed and they drop into the holes, into the cracks, and feed on that drip line. 

 And then they cause little leaks that  then have to be repaired. And that's costly, actually trying to fix all those leaks. So it is a challenge. And then one of my colleagues is looking at ways  to put a little bit of water in the line, maybe after harvest, just to seal up those cracks and and keep the rodents from dropping down and feeding on and nibbling on those lines, because fixing these rodent leaks and those drip lines is expensive and time consuming.   

[00:31:02] 

Farmer Fred: 

you mentioned flooding as a possible control for certain rodent pests. . And you mentioned snap traps for roof rats and deer mice. Are there any other less toxic alternatives?  

[00:31:12] 

Rachael Long: 

So, you do have traps for for gophers as well. 

And there's a lot work being done on gopher control in particular, and ground squirrel contro. These different units that use carbon dioxide or something,  that goes down the hole and takes care of these rodents. 
 So there are our options for many of our rodent pests and  some of these are registered for organic control as well.  I wish there were more options. Some people talk about  releasing cats. My concern about cats, certainly, is that they eat everything so well. 

They may eat some rodents, but they're gonna eat birds and lizards and  snakes or anything out there as well. So that concerns me. people are promoting cats, but cats are not specific on controlling just the rodents. So I wouldn't go that route. But  certainly the traps.
 And some people use barriers, they'll put a fence down and bury it so that and put it like a foot above ground so the gophers and such can't can't go in. Certainly for us, for some habitat plantings or plants, they'll put something around the root so that so it protects it more from the  rodents. You've got tree tubes. So there's multiple ways of trying to control the rodent.  

[00:32:28] 

Farmer Fred: 

So when it comes to roof rats though, there are limited options if you want to try to avoid rodenticides.  

[00:32:33] 

Rachael Long: 

The big thing is with roof rats and rats in general is they are smart, they're very clever, they're shy of anything new and they're very wary. 

 So the roof rats are a challenge. And so essentially, the best thing, certainly for homeowners, are snap traps. And then try that for maybe a few local infestations on a farm. But if you've got an outbreak and you're getting damaged, then you need to go to the bait stations up in the trees for managing the rodents. 

That said, you've really gotta be careful. Know when you can use it, because you can't use it in certain seasons for controlling the rodents. And so that's something to really watch for. And before it gets to that level,  it is really important to think about our wildlife and the natural control that  you can get out there by the birds and raptors, like  the hawks and also the  barn owls.
 And to try to do the local trapping to keep those rats under control. But some years, like this one, is one of the worst outbreaks of rats that we've had in a long time, in many years. And  It's in years like this where you do see a lot of damage, then you do need to be proactive and protect your trees. 

[00:33:46] 

Farmer Fred: 
  And if you want more information about Barn owls, for example, theuniversity of California has some great resources at the UCANR page, and check that out. Also, “managing roof rats and deermice in nut and fruit orchards”. That's available, as well, from UCANR. Check those out online as well. 
It's the year of  the rat.

[00:34:06] 

Rachael Long: 

It certainly is this year, and it’s always the year of something. And last year it was the year of the vole. I had so many voles out here in the country, It was unbelievable. And now we've moved on and it's the year of the rat.  

[00:34:20] 

Farmer Fred: 

Hopefully next year won't be grasshoppers. 

[00:34:22] 

Rachael Long:

 I hope not. Yeah, I haven't seen those. And just knock on wood that that it's gonna be a quiet year. 

[00:34:27] 

Farmer Fred: 

All right, Rachael Long UC Cooperative Extension Farm Advisor based in Woodland. Thanks for a few minutes of your time.   

[00:34:34] 

Rachael Long: 

You're most welcome. 

[00:34:40] Farmer Fred: 

The Garden Basics With Farmer Fred podcast comes out once a week, on Fridays. Plus the newsletter podcast, that comes with the Beyond the Garden Basics newsletter, continues, also released on Fridays. Both are free and are brought to you by Smart Pots and Dave Wilson Nursery. The Garden Basics podcast is available wherever podcasts are handed out, and that includes our home page, Garden Basics dot net. , where you can also sign up for the Beyond the Garden Basics newsletter and podcast. That’s Garden Basics dot net. or use the links in today’s show notes.  And thank you so much for listening.



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