I love avocado trees, and I sure love my son Miles, but toward the end of the summer his placenta tree started to lose leaves and then lose more leaves and then have some die back on branch tips, so I got emotional in a way I never have toward a tree. I’ve killed many trees over the years; it’s part of the learning process. But the prospect of killing the avocado tree that I planted over my son’s placenta upon his birth felt like failing as a father.
I dug around the base of the tree with my hands to find the problem. Was it a disease? Could I even save it? A healthy avocado tree has roots with white tips poking up into the mulch or leaf litter beneath it, but I found none. So I dug deeper. I found only a few roots. Where were they? Then my fingers poked into a cavity, I wiggled them in the air pocket, and I knew immediately where the roots had gone — or more accurately, who had eaten them. I followed the gopher tunnel more than halfway around the base of the tree. A gopher had eaten over half of the tree’s root system. A tree that loses roots sheds its leaves in order to bring its top into balance with its bottom.
I had never been angrier at a gopher. I immediately set every trap I had.
At the same time, I felt grateful that the buck-toothed varmint hadn’t finished off the tree entirely. Only a few weeks prior, another gopher had eaten to death a young Hass avocado tree I had planted in another part of the yard. Until the killing and damage to these two avocado trees, the Hass and Miles’s Sharwil, I had thought of the gophers in my yard as being a real threat only to my vegetables, which they had been attacking from day one. But now I had to patrol the rest of the yard where the fruit trees are too?
It’s appropriate that Miles and his Sharwil avocado tree would surprise us and require us to adapt. Miles was so calm and sleepy in his first few months of life that we were worried, and now — at one year old — he’s so loud and stubborn that we’re a little worried in a different way. In that photo at the top — our annual “pose with your placenta tree photo” — he squirmed out of Ursula’s lap to roll around on the ground and run toward me to grab my camera.
As for his placenta tree, I did catch the cause of its problems.
But only after a protracted hunt. So I’m adapting my methods and diversifying my arsenal.
The Cinch trap on the bottom represents my latest acquisition. The Cinch trap’s main benefit is that you don’t have to dig a big hole to set it. I have grown so tired of making craters around the yard in order to set pincer and box traps, especially within the vegetable beds. (I’ve also grown tired of standing near an active feeder hole to try and get a shot at a gopher’s head. Waste of time.) The Cinch trap can be inserted into a small surface opening to the gopher’s tunnel network. I’ve found it very effective so far. (Here are some videos that have helped me use it properly, done by master Cinch trapper Thomas Wittman.)
I dug around Miles’s Sharwil tree today to check for roots, to see if any had grown back in the past month or two since eliminating the gopher, and found some white tips. Hurray! Happiest I’ve ever been upon seeing avocado roots.
My lesson going forward is to immediately set traps whenever gopher presence is detected in the yard. There is more at stake than just plants.
Joel Salatin advises that you wake up every morning aiming to attack the weak link on your farm. That could be soil fertility, irrigation, labor efficiency, anything. The weak link in our yard has been — for a couple years now — a proliferation of earwigs and pill bugs. They grew in numbers as I spread more and more mulch under trees and around vegetable beds. They eat holes in strawberries, eat holey the leaves of peppers, eggplants, basil, and onions, and they eat the cotyledons of every single germinating seed. There is not even one species that they allow to germinate and grow up. This has necessitated that I grow all vegetables from seedlings purchased at the nursery, and this is the worst consequence of all, not being able to grow from seed.
Another piece of advice from Joel Salatin is to make a liability into an asset. The bugs have been a liability to me and my garden, but to chickens they are delectable food, an asset.
I can’t describe the pleasure I have found lately in watching the chickens devour these bugs. It is inordinate, sadistic, unalloyed, and I don’t apologize for it. It comes from a desire for revenge, true, but it also comes from seeing how happy I’m making the chickens, and just as much it comes from closing a resource loop, if you will. The bugs, which were once only a detraction, a cost, a liability, are now a resource, being put to use as feed for hens that will convert them, ultimately, into food for us in the form of eggs.
I’ve built a mobile pen so I can locate them over a patch of garden, focusing them on finding and eating all of the bugs in that particular 32 square feet, and constraining them from munching on any of the surrounding plants.
Yesterday, I left them over a bed where there had been strawberries. They didn’t eat every bug, but they ate most of them such that these basil seedlings that I put in today — after I moved the pen down the bed — should survive any damage the few remaining pill bugs might cause.
Keeping the pen rotating through the garden consistently ought to reduce the bug population overall enough for me to successfully grow from seed again soon. My future looks like this: I’ll have seeds germinating unmolested, chickens well fed, eggs, and even a further asset of manure. It’s only a shame that I waited so long to add the chickens in order to make use of the earwigs and pill bugs and fortify the yard’s weak link.
UPDATE, July 4: The basil seedlings have grown perfectly without any bug damage at all despite the presence of a few remaining pill bugs and earwigs as mentioned above.
Spent the last couple weeks in Oregon and Washington, and came home to notice a lot of leaves missing from an Early Girl tomato plant. Figured a hornworm had done some munching, but when I went to find it I found a second, and then a third, and then I kept finding more until I’d thrown this many on the ground beside the plant:
On one plant! Remember how big these guys are too — each one is the size of your finger, or bigger.
They were in heaven until I showed up. Now they are in the stomachs of the neighbors’ chickens.
UPDATE: Over the last couple days, I’ve found six more! That’s twenty hornworms on one tomato plant, and counting. And the plant is still growing like gangbusters in this late summer / early fall heat.
A couple of the native plants I put in last fall and winter, 2014:
Monkeyflower, still blooming here in August
The goal is to grow a hedgerow along the dirt road in order to mitigate dust created by cars and give more privacy to the yard and house. I’m using native plants for a number of reasons. They’re beautiful, for one. Also, after a year or two they’ll never ask me for another drop of water. In fact, if we get a wet winter they’ll be established and independent after only the next couple months. Further, they fit in to the larger ecosystem; they belong. So native bees use their pollen, hummingbirds drink their nectar, scrub jays eat their berries, and on and on.
The University of California recently conducted a study of native plant hedgerows on farms, and they found pest control benefits. “Tomato fields adjacent to [native] hedgerows required fewer pesticide treatments than the tomato fields without hedgerows.” Among other reasons, native insects living in the hedgerows fed on crop pests and thereby reduced the pest populations.
As the summer winds down, my mind turns from peppers and peaches to engelmann oaks and purple nightshade and sugarbush and black sage and elderberry and toyon. I’m getting excited to hike around the undeveloped parts of our yard as well as the neighborhood to collect seeds to plant along the roadside and restore the vegetation that likely existed before the road and our house were developed. Buckwheat, sumac, and ceanothus are on my radar, and Cass has already started gathering coast live oak acorns.
About a month ago a neighbor noted how poor my lime tree looked. She said her lemon tree didn’t have those “curly leaves” because she sprays it. A couple days later she brought over a blue bottle of the stuff she uses to spray: Bayer Advanced — Fruit, Citrus and Vegetable Insect Control.
She was right. My lime tree did look ragged, its foliage sparse and damaged from having leafminers the first two years of its life. Citrus leafminers are the insects whose larvae eat zig-zag tracks, or mines, in leaves. The leaves become curled and unsightly after the leafminers exit and turn into tiny moths. The moths then lay eggs which hatch and eat mines through leaves again, and so on.
I’m leery of spraying though. The only time I’ve ever done it was five years ago when I sprayed neem oil on a lemon tree because it was infested with aphids. The tree remained infested with aphids — until I took other measures to control the ants which were protecting the aphids from predators. I’m just not convinced of the effectiveness of many sprays, and I’m always questioning whether whatever short-term benefits they do have might be outweighed by broader, long-term harm.
But my lime tree looked so bad. It had yet to produce a single piece of fruit, and I began to think that spraying might be the only way to control these leafminers and keep the tree alive.
What’s in this blue bottle? Immediately, the active ingredient jumped out at me: imidacloprid. This chemical is the most widely used insecticide in the world. It has also had its use severely restricted by the European Commission starting in December 2013 due to its effect on honey bees.
Bayer CropScience, the developer and primary manufacturer of imidacloprid, both fought this decision by the European Commission and acknowledged the toxicity of the chemical to honey bees on the blue bottle I held in my hands. From the label: “This product is highly toxic to bees . . .” To reduce the risk of harm to bees, the label therefore recommends to “not apply until after trees have flowered or when bees are actively foraging.”
What happens is imidacloprid is taken into a tree’s system so that when a leafminer larva eats into a leaf it consumes some of the chemical and dies. But flowers are also part of the tree’s system, and when bees drink nectar from the tree’s flowers they also consume imidacloprid. They may not die, but there is sub-lethal harm all the same.
My lime tree wasn’t blooming at the time — this was February — but I knew that it was about to have its first bloom of the year. Then I read on the University of California’s Integrated Pest Management webpage for imidacloprid that the insecticide “can move into nectar, so don’t apply prior to bloom.” So the blue bottle’s label says not to apply imidacloprid until after bloom while the UC webpage says also not to apply before bloom. What? My only reading of that is that if you use imidacloprid you’re making a trade off: kill the leafminers at the expense of harming bees.
I gave the blue bottle back to my neighbor, unused.
More important than the health of my single lime tree was the health of the bees in my yard generally. My avocado trees and apricot and peach and orange trees were all about to start blooming too, not to mention all of my vegetables, and I needed these bees to help pollinate the whole yard. It was really a trade off between killing leafminers at the expense of less food throughout the entire yard.
In late February, the lime bloomed and it flushed new growth and it dropped many of its old and leafminer-damaged leaves, and here’s how it looks now:
To my surprise and delight, the foliage is as uniform and vibrant green as I could color with crayons. There are no leafminers apparent anywhere. How could they have been so populous and damaging last year and now non-existent? And how could this have happened without my help?
The UC IPM webpage about citrus leafminers says, “the best course of action is to leave it alone and let the natural enemies of the citrus leafminer feed on and parasitize the larvae in the mines, rather than trying to control this pest with insecticides.”
Natural enemies? These include tiny wasps such as Cirrospilus and Pnigalio species. The UC IPM webpage goes on to explain that they “lay their eggs inside the mine, inside or on top of the leafminer larva. When the parasite egg hatches, the parasite larva consumes the leafminer larva.”
My deduction is that these natural enemies of the leafminers have eaten the leafminers near my lime out of existence.
UC IPM: “In other areas of the world where the citrus leafminer invasion is long established, the experience has been similar: a high level of damage to citrus in the first year or two is followed by decreasing severity due to natural enemies parasitizing or consuming leafminers. These natural enemies, which are already present in the environment, survive by seeking out mining insects in which to lay their eggs. Eventually, the leafminer populations decline as the population of natural enemies increases.”
My lime tree didn’t need my help, and it certainly didn’t need the “help” of imidacloprid. It needed only to be left alone. What if these facts were also stated on the label of the blue bottle of Bayer Advanced?
UPDATE: It’s May of 2016 now, a year after deciding not to spray imidacloprid, and this spring’s flush has just finished on the lime as well as the other four citrus trees in the yard. Not a single leaf with leafminer damage on any of them.
The Bearss lime in May 2016