Like its Brassica relatives, cauliflower, Brassica oleracea var. botrytis, is prone to pests that pose a threat to the success of the crop.
And in addition to the damage that pests can cause to developing heads, foliage, and roots, they can also be vectors or carriers of plant diseases that can be detrimental to an even greater degree.
In our cauliflower growing guide, we discuss everything you need to know to grow and care for your own plants.
In this article, we present nine common cauliflower pests and diseases that you will learn to recognize and control. Here’s the lineup. Let’s get in right away!
1. Cross-Striped Cabbage Worms
According to professionals at the University of Massachusetts Amherst Center for Agriculture, Food and the Environment, the cross-striped cabbage bollworm, Evergestis rimosalis, is easily distinguished from other Brassica pests at the egg stage.
This is because it is the only species that lays eggs in clusters that look like flat yellow spots on the underside of foliage.
The larva, or caterpillar, is bluish gray with black stripes on top and solid green below.
It feeds on leaves, working its way up to the heads before maturing into the brown moth with translucent underwings you may notice fluttering around your plants. You can manually pick out caterpillars when you see them, or you can be proactive with biological control.
An effective course of action is the use of moth egg parasites, Trichogramma brassicae. These are parasitic wasps that feed on the eggs before they hatch. This approach works best in cooler regions. This is a process of releasing predators every week after the moths first appear, so that they are in place when the eggs are laid. Small and non-stinging, these beneficial insects live for about two weeks.
Moth Egg Parasites
Purchased wasps are shipped in the egg phase, attached to cards. You hang them near the cauliflower plants, out of direct sunlight, where the moths are active. When they hatch, the wasps search for their prey.
Be careful not to touch the fragile eggs when placing the cards. You can also treat an outbreak with an application of Bt or pyrethrin, the organic pesticides described above.
And you can also attract parasitic wasps to the garden with umbel flowers that have flattened heads covered in tiny flowers.
The cabbage aphid, Brevicoryne brassicae, is a tiny sap-sucking insect that eats through leaves and heads.
It can spread several types of diseases, including cauliflower mosaic virus, and leaves a trail of honeydew that promotes the growth of a fungus that causes sooty mold.
The eggs are laid on the underside of leaves and are so small that you may never see them. However, the telltale clusters of stacked aphids are visible as a yellowish patch.
Start by trying to rinse them off with a steady, steady stream of water from the hose.
If this proves ineffective, use a product such as neem oil, a natural insecticide and fungicide.
Bonida neem oil
Neem oil is organic and is derived from the neem seed. In addition to being a gold standard insecticide for many pests, it is an effective fungicide that is chemical-free and non-toxic to people and pets.
3. Cabbage Moths
According to experts at Michigan State University Agricultural Extension, the cabbage moth, also known as the diamondback moth, Plutella xylostella, is one of the most destructive insects when it comes to brassica crops.
Immature larvae are transparent yellow, but change color as they mature and may have green/yellow, brown, or black stripes. Adults are easily identified by a white diamond on their folded brown wings.
Both larvae and adults are voracious feeders, decimating entire plants. If you notice the moth, look for yellow to green eggs on the undersides of leaves. This is a difficult insect to treat as it has developed resistance to some pesticides. Natural predators include the parasitic wasp, a beneficial insect.
You can try neem or Bt oil, but you may find that they are not effective. It involves planting a barrier of another plant that the pest likes around your brassica. In this case, kale is recommended.
The idea is that these moths chew on the cabbage before attacking the cauliflower. At best, you can enjoy both crops at harvest time.
4. Slugs and Snails
If you see slimy trails and jagged holes with smooth margins, you no doubt have the fleshy gastropods commonly known as snails and slugs in your garden.
From their homes deep in the ground, where they live and lay their eggs, these night-feeding pests emerge.
They are most active when the weather is cloudy, cool and humid, preferring shady places and conditions with excess water.
Suggested remedies vary. Many involve luring gastropods into containers from which they cannot escape, such as
Snailer Snail and Slug Trap.
Choose from a single trap with a month’s supply of bait; two traps with four two-month baits; a two-month bait refill and a pack of five two-month bait refills. They are safe to use around people and pets.
Other treatments include products that contain iron phosphate. They are not toxic to people or pets and cause slugs and snails to lose their ability to feed.
Bonide Slug Magic
This product comes in granular form and is sprayed on the ground around affected plants.
Remember not to overwater. As stated in our grow guide, one to two inches of water per week is generally sufficient in the absence of rain.
5. Cabbage White Butterflies
Pieris rapae lays yellow eggs on the underside of Brassica leaves. They contain larvae, or caterpillars, which hatch with a voracious appetite.
Also called cabbage worms or green worms, these caterpillars devour the leaves and pierce the heads, ruining entire crops.
>>> See more: how to prevent tomato blight
6. Cabbage Whiteflies
Another pest you may see is the cabbage whitefly, Aleyrodes proletella.
This tiny whitefly and its young scaly nymphs infest the undersides of leaves, feeding on leaf sap and excreting “honeydew” that promotes sooty mold growth.
But while this type of whitefly disfigures a plant’s leaves, it doesn’t damage the heads, so many growers simply tolerate it.
Experts at the Royal Horticultural Society are of the opinion that unless an infestation is severe, it probably won’t need to be treated with pesticides.
However, if you do choose that route, know that treating the undersides of the leaves is a temporary fix, and product instructions should be followed diligently with reference to selecting the right one for the right crop, as well as safe harvest intervals for the crop. app.
An organic approach to eradicating whiteflies includes the introduction of a beneficial insect to the orchard, namely lacewings, Chrysoperla rufilabris.
Adult lacewings feed on whiteflies and caterpillars, making them a valuable addition to the garden. They live for four to six weeks.
7. Cabbage Loopers
Trichoplusia ni is a leaf eater that can chew a crop to nothing in a very short time.
This caterpillar is unmistakable, with its distinctive inchworm-like gait, green body, and white stripe. Adults are brown moths with a distinctive silver figure-of-eight marking.
Small yellowish-white eggs are laid on the underside of the leaves.
Cabbage loops do their worst damage to mature plants, tearing at the leaves and right into the flower heads.
A treatment with organic Bacillus thuringiensis, or Bt, is recommended.
It will not harm beneficial insects such as the tachinid fly, which feeds on various caterpillar pests and is readily available under numerous brand names.
Find Bonide Thuricide in quart, gallon, eight-ounce, and 16-ounce packages.
Or, you can try a home remedy from Sharon Lovejoy, horticulturist and author of “Trowel & Error,” a collection of gardening tips.
She recommends sprinkling the plants with white (non-rising) flour early in the morning. Dew plus flour equals petrified bugs that can be rinsed off the next day.
8. Flea Beetles
The cruciferous flea beetle, Phyllotreta cruciferae, and the striped flea beetle, Phyllotreta striolata, chew through the leaves of brassicas, but usually make shallow cuts that don’t go all the way through the leaves.
You can mostly recognize them by their extra-large hind legs that allow them to jump like fleas.
A foliar spray of pyrethroid is the recommended chemical treatment. This is a synthetic compound not to be confused with natural pyrethrin, which has a botanical derivation.
There is no organic product available for the treatment of flea beetles. However, the use of floating row covers, or planting around the life cycle of the beetles, can be helpful.
You can also try trap growing as a first line of defense with a favorite flea beetle, the mustard beetle.
9. Cabbage Root Maggots
This rootworm, Delia radicum, is the larva of the cabbage root fly.
This tiny brown fly lays tiny 1/8-inch eggs that contain white larvae or maggots. When they hatch, the worms feed on the roots of Brassica crops.
If you see an excessive number of tiny flies around your crops, apply diatomaceous earth to the soil over the roots to discourage egg laying.
And if your plants show signs of distress, dig up, examine the roots, and discard infested plants.
Alternatively, you can try an application of nematodes, Steinernema feltiae, which are microscopic worms that attack soil pests.
NemAttack Sf Beneficial Nematodes
There’s something else you might want to try: a necklace. This is a circle of felt, cardboard, or a similar material that surrounds a plant at ground level to prevent flies from laying eggs near the roots.
Find it at garden centers or make it yourself.
Goodbye Cauliflower Pests And Diseases
Watch for signs of their presence, such as eggs under leaves; caterpillars; hoverflies, brown moths and small white butterflies; as well as chewed foliage and heads.
If the idea of having to monitor and control pests really puts you off when it comes to gardening, wait! Before you put down that shovel, there’s another way.
By placing those floating row covers we mentioned over crops early on, you can greatly reduce the potential for insect damage. They are also helpful when the temperature suddenly plummets or rises above normal. Additionally, you may want to do raised bed or container gardening to minimize the risk of infestation by ground-dwelling insects.
Where there is a will, there is a way, and when you reap that first harvest, your efforts will be deliciously rewarded. Have you dealt with cauliflower pests? Please share your experience with Answer The Question in the comments section below.