Category — Pests

Ricinus communis ‘Carmencita’: the spectacular castor bean pods almost obscure the inconspicuous flowers, just visible below.

Sad news. Gophers and castor oil do mix. At least in some gardens.

Last report, I was experimenting with saturating some cutting-flower bed soils with castor oil solution. This had worked for me before in my tulip beds, where I didn’t water in summer.

I was also keeping tabs on a friend’s garden: she planted castor bean plants around the perimeter of her garden in New Mexico, and had good results keeping gophers away. Unfortunately, this doesn’t seem to be working in her garden here. Gophers are happily working away amongst these castor bean plants. (They are ‘Carmencita’ plants, by the way, for those of you who just want to grow them because they look so cool.)

I had a theory going for awhile: the studies attesting to the efficacy of castor oil sprays on the soil were done by the University of Michigan. And the woman who recommended it in Gardener’s Supply (a catalogue where I’ve found lots of useful and interesting, well, garden supplies) is also from the midwest.

So my theory was this: in the midwest, where it rains all summer (to excess, this summer), the soil is always moist. The midwest also has a lot of naturally fluffy soil (where it hasn’t been eroded away by bad agribusiness practices). That means that there are green things growing in fluffy moist soil all over. So a gopher has a choice between plants in fluffy moist soil without nasty castor oil, or with it. Any sensible gopher would choose without.

In my dry-summer area, though, the only place you see green plants in summer is where people are watering or where there’s a creek. And while there are some deposits of naturally fluffy soil, they are few. Clay, decomposed granite, and composed granite are the lot of most of us. If we want fluffy soil, we have to work at it. So in my area, if a gopher wants nice fluffy easy soil to burrow through, and moisture and plants, it’s most likely going to find them in a garden. And nowhere else.

The thing that throws a wrench in this theory is the New Mexico story. New Mexico has dry summers, too, and as far as I know is not known for fluffy soil. (If I’m wrong about this, let me know.) So why did the castor bean plants work there? Was it just that the gophers hadn’t found that garden yet? (It does take them awhile.) Or something else?

Life is an ever-turning mystery.

Another friend of mine, who has a master’s in agriculture, gave me some things to think about when I relayed this story to her. Was the type of gopher different in the places where the castor oil was effective? That could be crucial. Do all cultivars of castor bean have the same amount of toxins? It is often true that medicinal plants that are bred to have better looks lose some of the medicinal qualities. (Yarrow is just one example of this.)

I took her advice and delved a little deeper: it turns out the University of Michigan study was for moles, not gophers, and Glenn Dudderer is testing it as a chipmunk and squirrel repellent.

But, you will notice, not as a gopher repellent. And even as a mole repellent, castor oil seems to have gotten mixed reviews: Mole Patrol is now the latest in anti-mole materiel. And even the Gardener’s Supply catalogue now concentrates on moles and downplays the gophers when it comes to castor-oil repellents.

Even though it might not be the heavenly gopher cure-all, castor bean plants are really beautiful. Just be aware that, though the oil is edible, and has many medicinal uses, every other part of the plant is highly poisonous. (In fact, I read a gruesome true story of how a woman poisoned her husband by putting the crushed-up beans in his food. Truly a case of an unfortunate U.S. cultural trait: kill first, talk about it later.) Don’t plant them where small children can investigate the pretty seedpods and attractive leaves.

If you have success in keeping gophers out of your garden with castor bean plants or castor oil, let me know. I’m still trying to figure out why they work in some circumstances, and not others.

References:

Gardener’s Supply catalogue

Herbalhut.com, “Natural Animal Repellents”

Michigan State University Extension: Pests

Prinses Irene tulip–one of the many garden plants gophers like to eat. I haven’t found a way to make gopher mounds look artistic, and I refuse to make the effort it would take to get a picture of a gopher. So this picture is a memorial to the tulips I’ve lost to gophers.
How can I love you when you won’t go away?
This summer I’m doing an experiment. I was going to make a raised bed in the sun for cutting flowers, with chicken wire on the bottom to keep the gophers out. This is a common local remedy for gopher invasion, and it generally works until the wire rusts out.

But being as I’m unhandy and unindustrious, I’ve been putting off the evil hour when I would have to do the building-the-raised-bed part. (The boyfriend in part 1 of this story has long since departed–probably the best thing for both of us.) Me and boards and measurements and tools, well, it’s not a pretty sight. I knew at the least I’d be losing my temper, and that most probably it would take about four times as long as I thought it should.

So when we had some welcome spring rain–well, I just started digging. I’m doing a sort of half-baked version of double digging, where you dig up a crater, then refill it with the soil mixed with amendments, so it fluffs up over the top of the original soil line, providing drainage and good root growth space for the plants.

And I thought, while I have that crater dug out, I’ll just soak it down with some castor oil solution. It leaches in the rain, but I wanted it to leach. I wanted it to go far down into the ground, where it would discourage any gophers in the neighborhood, and send them another direction.

I’d heard you could make your own castor oil solution, and remembered seeing the recipe at answers.yahoo.com. The only thing I did differently was to use a hand whisk and mix the soap and oil in the measuring cup instead of using a blender. Unless you have a predilection for washing equipment, I’d recommend this method, since it only takes about ten seconds to whip them together. Then you add in some water; that takes five seconds more. Put it in a jar with a lid and shake before using.

I put the castor oil solution in my sprayer in the recommended dilution, and soaked the bottom and sides of the cutting bed thoroughly. Later I will soak the upper layers of soil the same way, and I’ll have to keep that up about once a month–not too strenuous a schedule. (Especially since I’m not planning to have a huge flower bed, in keeping with my Nonindustrious Gardener status.) I’ll keep you posted as to whether this experiment works.

Right now the rain is leaching castor oil, I hope, far far into the ground.

 What I didn’t get the first year I tried to grow tulips.

I learned to loathe gophers early in life. My gardening life, that is.

Years ago, my boyfriend and I, still freshly enthusiastic about the back-to-the-land life, built a raised bed for my tulips. I had ordered fifty bulbs for something like $4 from the Michigan Bulb company-this was back before I cared what kind or what grade of tulips I got. I was just happy to get whatever tulips they’d send me at that price, since I was on a tight budget.

We hauled sand from the creekbed in the big truck. We gathered horse manure from the pasture. He built the frame for the raised bed, and I planted the tulips, looking forward to a beautiful spring.

When it came, I had one–count it, one–tulip. When we investigated, we found the rest of the bed was riddled with gopher holes. Gophers love tulips, yum yum. They also got most of our potatoes that year.

That was the year I stopped thinking that I could get along in sweet harmony with all the animals in the forest, just like Snow White. That was the year I began to despise and fear gophers.

Planting in containers has solved virtually all my gopher problems. But I have done some planting in the ground, and for a while I used a commercial preparation of castor oil to soak my soil and keep away gophers. (I found it in a handy hose sprayer bottle in the Gardener’s Supply catalogue. It’s also available at Peaceful Valley Farm Supply ).

(Note: no, I didn’t get paid to make the above links. I really think these are good companies. If in future I do get paid for links, I will link only to places I think are worth your time. And mine. (I don’t get paid for extraordinary use of parens, either.))

The theory is that the gophers don’t like the smell or texture of soil when it’s saturated with castor oil, and avoid it. I had good luck in keeping gophers away, just as advertised.

But the soil I sprayed it on was soil I didn’t water in summer (in my climate, it rarely rains in summer, so the soil is dry except where you irrigate, or where there’s a bog.). It was, in fact, to protect my tulips, which I was daring to grow once again.

By this time I had learned that tulips don’t like summer water, which was good, since the well I was on went to a tiny trickle in summer. I was glad I could grow tulips, and determined that this time the gophers wouldn’t get them.

The problem with this test is that it was only partly conclusive: the gophers didn’t get my tulips this time, but they generally are more attracted to soil that’s watered in summer. When I stopped using the castor oil, they still didn’t get the tulips in that bed.

Next post: new adventures with castor oil. Nothing kinky.