Episode 10: Wherein Organigirl Introduces You to A Common Enemy of Beets and Chard - The Leafminer

A Bull's Blood Beet. Delicious and colorful. It's no wonder the leafminers flock to them...

Last year I planted some beets in a random plot in my garden.  Despite the plot being completely crawling with earthworms (a sign of good soil, by the way), my beets didn't grow. I take that back - I think two of them grew. Two. I planted a couple rows of swiss chard right next to the beets, so one would think that the chard, which is basically the same plant as beets but cultivated for the leaves rather than the root, would have also given up the ghost. Wrong! The chard grew like mad, and it was glorious, and we celebrated and did funny little harvest dances, and ate chard as if it doing so would bring us eternal youth and good fortune. Our merriment, however, was short lived.

After enjoying weeks of chard in soups, salads, and straight to my mouth, something strange happened. I began to notice little brown spots on the chard leaves. Some of them had holes in them. Some of them looked almost like a fungus had taken hold. And all of the affected plants looked, well, unappetizing.

Leafminer damage on a beet leaf. Would you want to eat something that looked like this? 

As the days went on, I went into mourning. I cloaked myself in nauseating shades of brown to express my deep sorrow - as all gardeners do during times of gardening tragedy. Friends began to wonder what had happened to my green cape, and asked if I was photosynthesizing enough. Neighbors, on more than one occasion, heard my pitiful sobbing and brought be fruit baskets and cheese logs, and offered to have my windows sound proofed. Even the gnomes ceased from making their mischief for a while, leaving me convinced that they were somehow to blame for my predicament (and I'm quite sure, as always, that they were) and feeling a bit guilty. Gnomes have feelings too you know. And I had some feelings of my own. I was utterly distraught.

I recalled the year before, when I had noticed similar spots on the leaves of my beet plants. I had suspected a fungus then as well, but since the damage to the leaves wasn't affecting my beet roots, my curiosity stopped at wondering. This year, however, the same ugly brown spots were making my chard virtually inedible, so I began to scour the internet in search of clues. What I discovered was just plain yucky. 

The spots I was seeing on my chard plants weren't caused by a fungus at all. Instead, tiny maggots were burrowing in between the layers of my chard leaves - eating the insides of the leaves and leaving little trails of emptiness. And poop. (I did warn you about it being yucky at the end of my last paragraph, so hopefully you had taken a moment to mentally prepare yourself. Gardening is a dirty, dirty business you see.)

And who were these little critters that were eating the life out of my chard and leaving their filth behind? None other than the dreadful leafminer. Even now I shudder at the mere thought of them and have the sudden urge to run out to the garden and cuddle all of my veggies close and promise them that everything will be alright - but I think I've given the neighbors enough to talk about already, don't you?

Once I had identified the culprits, I tried to figure out some way to send them packing. I picked off affected leaves (many, many affected leaves) in the hopes of rehabilitating my plants, but to no avail. I even resorted to using...an organic pesticide (which is very much against my Organigirl Code of Gardening Conduct). I covered the chart in a fine layer of Neem spray, and then blanketed them with floating row cover, but it was too late. My chard was overrun with the devilish leafminers, and I finally pulled every last chard plant out roots and all. It was a sad, sad day for Organigirl.

The silver lining in my tale of woe is that there are some preventative measures that you can take to keep your chard and beets from meeting their maker in the same way mine did. Here's the long and short of it.

CROP ROTATION

When you grow plants susceptible to leafminers in the same spot year after year, the problem intensifies rapidly. Why? Because during part of the life cycle of leafminers, the pupae lie dormant in the soil. If they wake up to find their preferred snack all around them, they'll happily grow and multiply - making the problem worse year after year. If they wake up and find, say, carrots, they're going to go searching for a tastier snack elsewhere - and hopefully they'll get picked off by birds or predator insects in the process.

If you're new to the world of growing vegetables, or if you're simply unfamiliar with the concept of crop rotation, you may want to check out my post about it. In addition to the information you find there, you'll also notice that when visiting my vegetable growing guide, the vegetables are arranged by crop rotation category. This is to help you to learn how to easily categorize your crops in order to make rotation easier. 

ROW COVERS

In addition to giving pests the slip by way of rotating crops, you may also want to use row covers to keep leafminers from being able to invade your plants from above. Leafminer maggots will eventually grow to become a type of fly. Those flies lay eggs on the leaves of your chard, beets, and other favorite plants of theirs. Those eggs look like teeny tiny skinny white good-n-plentys (have I ruined good-n-plentys for you now? Sorry.), and they are usually found in clusters. When they hatch, the leafminer maggots emerge and tunnel into your plant leaves. This is how an infestation usually begins, and stopping it before it starts is a great way to ensure that you, rather than the bugs, are enjoying the fruits (veggies?) of your garden labors.

If you're wondering how to install row covers in your raised beds, take heart. A related post is coming soon - complete with pictures and Organigirl brand humor!

Leafminer eggs on a beet leaf. Each white spot on this leaf is a cluster of a few eggs. 

SEASONAL AVOIDANCE

In your area, it's possible that leafminers are only active in, say, the spring. Some gardeners choose to grow susceptible crops during times of the year when leafminers are least active. While this is a great way to minimize crop damage, it also means giving up chard and beets (and sometimes even spinach!) for months out of the year, and that's just not my style. I can't imagine a summer without chard or beets!

Since that terrible summer when I lost my entire crop of chard (it was only last year! It feels like it was just yesterday...), garden therapy has done wonders for me, and my gloomy gloom has turned into a bright and shiny bolting lettuce of optimism (note my poor use of garden metaphor. It's important and you really should note it or you'll forget all about it and have nothing to groan at later. You're welcome). I'm now resolved to make this year in my garden the best year ever for my chard and beets. I'm pulling out all the stops. And all the leafminers - if there are any. But with any luck, they'll get lost, eaten, or repelled while in search of yummy things in my potager - and the yummy things will all be left for me - completely unscathed, and completely delicious.