As the growing season progresses, the home gardener and large scale grower are often faced with garden pests and even diseases. Often times, we feel as if the battle is never in our favor, and we end up leaving the season feeling defeated.
Red Barn Acres practices organic growing policies, following closely the guidelines set forth by Eliot Coleman, a pioneer in organic growing. We are not USDA Certified Organic nor do we ever intend to become certified (a lot of the USDA guidelines fall below our own personal high standards). We are often asked how to control pests or diseases, and while we’ve been growing our own food for quite some time, there is always something to be learned, especially if we have never dealt with the issue at hand before.
We only use OMRI certified sprays when all other forms of intervention have failed. We manually check our plants for infestations or signs of a looming infestation every few days. We use blue and yellow sticky traps to monitor the pests at hand. We even hand pick pests off of plants, too! Right now, we are dealing with Cucumber Beetles snacking on our plants and produce and have been hand-picking them off the plants and smooshing them or throwing them into a bucket of water.
Below you will find a list of some common pests and the organic solution.
The Tomato Hornworm is probably the most common pest in the home garden. Every year it seems like these guys show up and decimate a whole garden of tomato plants in one night. They devour the leaves, stems, and fruit of the tomato plant. I have also seen them on pepper plants, egg plant, and tomatillo plants. It is easy to tell if your garden has been infested by these little devils by the feces they leave behind (dark brown or black “pebbles” or dark green “pebbles” if they’re recently gorging) on the leaves of your tomato plants.
The good news is, they’re easy to spot and easy to rid from your garden. My go-to plan of attack is to remove them from the plants. I am not a huge fan of the way they feel when I touch them, so I usually just cut the branch off that they are on. My favorite way to get rid of them is to knock them off into a bucket of water. Usually, they hide from the sunlight during the day under the leaves of the plant. I have better luck looking for them at night with a bright flash light.
Tomato plants release a chemical when eaten, and therefore make the worm itself bitter tasting, which the worm uses as its first line of defense against predators. These guys are not tasty snacks to birds, chickens, or other animals. Trust me, my chickens look at them and run away, and I am sure they wonder if I am trying to trick them! Other people stomp on them, creating a green goo in the soil.
The Tomato Hornworm does have some natural predators, like ladybird beetles will feast on the young tiny worms, green lacewig larvae also feast upon the young worms. There are also wasps, braconid wasps to be exact, that will lay its eggs inside the body of the worm and eventually the wasp larvae will eat the tomato worm.
There are a few organic chemicals you can use that are not harmful to the plant, the environment, the soil, or humans. One of those is BT (Bacillus thuringiensis) which is a naturally occurring bacterium, which is found in the soil and it causes diseases in some insects, especially the leaf consuming worms. BT works by paralyzing the digestive system of the insect that feeds upon the leaf of a treated plant. Another option is spinosad, which contains the bacterium Saccharopolyspora spinosa . It was discovered in 1982 in a Caribbean rum still. Spinosad works as a neurotoxin in many insects. It causes the insect to become overly excited to the point of exhaustion, and finally death. Spinosad should only be sprayed at dusk on a calm evening, after all beneficial insects have left for the day.
As for our farm, we use Spinosad and BT when needed. We spray Spinosad on plants in the brassica family (cabbage, kale, broccoli, cauliflower, brussels sprouts) to prevent cabbage worms from destroying our plants. We only spray at the beginning of the season when the plants are young and from then on, we monitor the plants for damage. We also use it on our tomato plants when hand picking the worms has made no change in the worm population.
According to the Old Farmer’s Almanac, cabbage worms are the same pests as “imported cabbage worms” . The adult butterflies are often called Cabbage Whites or Small Whites. These guys are commonly found on broccoli, cabbage, kale, cauliflower, kohlrabi and other plants of the brassica family.
There are also cabbage loopers, which look a lot like cabbage worms but do not have legs in the middle of their bodies. They are yellow-green in color. They do the same amount as damage as the cabbage worms and are controlled in the same ways.
The damage the cabbage worm does is usually only cause for concern when the plants are small with not much leave mass. If the plant is closer to adult size, the damage done by cabbage worms usually does not effect the plant.
Above is a photo of the damage done by cabbage worms (a large infestation it looks like!) Fortunately, there are many organic ways of removing and controlling the worms. One way is to hand pick them off the plants (of course, the insect must meet its demise or it will find its way back). You can also use yellow sticky traps to attract the butterflies that will lay the eggs on the underside of the plant’s leaves.
Another option is spraying BT or Spinosad, as mentioned above in the Tomato Hornworm section. There is also an old farmer’s anecdote where you dampen the leaves of the plants and sprinkle with corn meal. The worms then eat the cornmeal and the meal swells within their digestive tracts causing them to “explode” and die.
I think that Squash Bugs are probably the WORST pests. These guys do MAJOR damage, and if you do not catch them in the early stages – laying eggs – and those eggs hatch, it just goes down hill from there. Last year, we lost an entire pumpkin crop as well as all our zucchini and melons to these guys. It was NOT pretty. The adult bugs have piercers that they pierce into the plant leaves and stems and suck the juice or liquids from the plants, causing them to turn yellow and brown. Healthy plants may not succumb to the piercing and loss of liquids as much as unhealthy plants, but a large enough infestation can cause some serious devastation. The photo below shows the beginning signs of a squash bug infestation.
The adult bugs overwinter under the shelter of plant debris or other materials in the landscape. When it warms in the spring, they fly around looking for places to mate and eventually lay their eggs. Unfortunately, they lay them on the underside of curcubit plants like squash and cucumbers. Adult females usually show up around June and keep laying eggs through the summer.
The adult females lay eggs in clusters of about 20. The good news is, you can get the eggs off using some tape, the eggs stick to the tape and come off the plant. Their eggs are a reddish color and oblong in shape. They are usually laid in between the veins of the leaf, as seen in the photo. They hatch in about 10 days.
There are a few ways to manage these pests. One way, like mentioned above, is to remove the eggs. You can also crush the eggs with your fingers. Once the eggs have hatched, you can drop the nymphs into a bucket of soapy water and they’ll meet their maker. You can also do the same thing with the adult squash bugs. If you crush the adults, BEWARE! They release an unpleasant aroma similar to stink bug smell!
When all the options above have failed us or we feel extremely overwhelmed, we use an OMRI certified spray derived from the Chrysanthemum plant called Pyrethrin.
My first experience with flea beetles was last year when I could not figure out how I was getting bit all over. Then I discovered these tiny little black beetles all over, and decided to look them up to see what they were. And they act JUST LIKE fleas! They literally jump high and far like fleas do when they are disturbed and their bites feel and itch just like a flea bite.
In gardens, the female will lay eggs in clusters in the soil, in the roots, or leaves of many different plants. They initially feed upon the roots and root hairs of the plants, but this does not cause enough damage to be noticeable. They are commonly found on cabbage, cucumbers, turnips, radishes, egg plant, peppers, tomatoes, potatoes, spinach, and melons. The damage that these little beetles cause can be seen in the photo above.
One way of managing them is to plant a “trap crop” which means you pretty much give the flea beetles something to eat in hopes that they leave your main crop alone. Trap crops should always be planted before you plan to plant the crops which you plan to keep or sell, to insure that the flea beetles feast on the trap crop. The photo to the right shows a trap crop of mustard greens and the cash crop (the crop you wish to sell or keep for yourself) is broccoli. The mustard greens are keeping the beetles busy while leaving the broccoli alone.
Another way to organically manage the flea beetle is to plant companion plants. Companion plants are usually plants that help benefit the main crop plant by either repelling pests and attracting beneficial insects. Bunching green onions, marigolds, and dill are a few examples of beneficial companion plants for brassicas. They help to repel and deter the flea beetles.
The most common way to keep flee beetles off from your cash crops is to use insect netting. Our farm currently does not have any of this (it was mostly sold out when we wanted to purchase it and it is also slightly expensive). Insect netting is draped over your crops before any sign of pests, and touches the garden soil, and is generally held down by bags of stones or logs, or whatever you have to hold the netting in place. It is most commonly used in large market garden operations.
Some other methods consist of using predatory beneficial insects like praying mantis, parasitic nematodes (live in soil), yellow sticky traps, Pyrethrin spray, and Spinosad spray.
In the United States, there are 2 types of cucumber beetles that are quite common. The first, on the left is the Spotted Cucumber Beetle, which is more common on the western and southern parts of the country. The beetle on the right is known as the Striped Cucumber beetle and is very common in the north and eastern states.
The difference between the two is that the Spotted Cucumber Beetle is known to feed on over 200 different plants, including crop plants and non crop plants. The Striped Cucumber Beetle is very keen on cucurbits (cucumbers, pumpkins, etc) and rarely feed on other plants. The Striped Beetle feeds on leaves, stems, and flowers. The Striped beetle lays its eggs near the base of the cucumber plant and then the larvae feed on the roots of the plants. The spotted beetle is more common in the southern states, and will lay its eggs on corn or grasses therefor the larvae are not prone to damaging the roots of cucurbit plants.
The damage done by these beetles happens in a few ways. First, the plants themselves are damaged during feeding, which causes stunted plant growth and slow fruit set. Second, the beetles are generally carriers of bacterial wilt disease. Thirdly, the feeding on the fruits of the plants cause the fruit to not be marketable.
Luckily for us, the beetles have some natural predators that include wolf spiders and ground beetles. I am not a fan of spiders (not one bit!) but I do leave any spiders that are in the garden be. They are doing their job and getting rid of pesky insects. The ground beetles are not often seen, I think they mostly come out at night or when you dig up ground or even when you flip something over that’s been sitting on top of the ground for a while.
Lately, I have been hand picking these little guys off the cucumber plant itself. They like to hide in the blossoms as well as the very new growth at the end of the vine. They suddenly drop off the plant, so make sure you have a bucket or cup or your hand underneath the plant when you go to snatch them. I stick them right on the sticky traps or I smoosh them with my fingers.
You can spray Pyrethrin spray, which is what our last step will be if they get to where we cannot manage them by hand picking them off.