Tansy is a thorn in the side of many hobby gardeners because it spreads quickly in the garden. However, if you leave it, it serves as a natural plant protection against numerous pests.

In a nutshell

  • Tansy contains the neurotoxin thujone
  • helps against many pests
  • also kills beneficial insects
  • Tansy as a biological crop protection only at certain times and when needed

tansy

Tansy (Tanacetum vulgare) is a species of plant in the genus Tanacetum. As with many species from this plant genus, the genus name says it all in the case of tansy, because the perennial, herbaceous plant is proliferating. Therefore, tansy is often fought as a weed. On the other hand, it acts as a natural crop protection agent.

Tansy as biological crop protection

Tansy contains many essential oils, which are not only responsible for its smell, but also for its function as a natural plant protection agent. Of particular note are the contained thujone, which is also known under the name absinthol. Since the substances are nerve toxins, tansy should only be used as biological plant protection. Consumption of the plant is strongly discouraged as it can cause severe poisoning.

The thujone are also the reason why tansy does not act selectively as a biological crop protection. This means that the application of Tanacatum vulgare not only destroys pests but also beneficial insects. To protect the latter from the toxic substances, consider tansy

  • use only when necessary or at certain times of the year,
  • spray only in the evening (bee flight) and
  • do not dispose of the spray in the compost.

Although thujone becomes harmless over time under UV exposure, the so-called waiting times are between 12 days and a good four weeks. Therefore, fruit from fruit and vegetable plants that have been treated with tansy during this period should be not consume. If the waiting time is outside of fruit formation or harvest time, there is hardly any danger to humans.

dosage forms

Tansy as a natural crop protection is used as manure, tea or broth. The aerial parts of the plant are sometimes used as a contact poison.

tansy broth

For the preparation you need:

  • 300 grams of fresh or 30 grams of dried tansy
  • 10 liters of water

Soak the tansy in water for 24 hours. Then let the mixture simmer for 20 minutes. Cover the broth to cool. When cool, strain off the plant remains. Then express them well.

For pouring, the broth is used undiluted. If it is used as a spray, it usually has to be diluted.

Tip: Since the proportion of the active ingredients is highest in the flowers, you should use flowering tansy. The flowering period is from June to September.

tansy tea

For a tansy tea, pour one liter of boiling water over 30 grams of dried or 300 grams of fresh tansy flowers. After a brewing time of 24 hours, the tea is ready for use.

apply tansy

Because tansy is a neurotoxin, it helps against a variety of pests. Nonetheless, broth, tea, or manure should be used with caution. In acute cases, tansy is used several times in a row and approximately every three to five days. If you are unsure whether you should continue the spray treatment, the rule applies: less is more.

bugs and fleas

Strawberry blossom weevil (Anthonomus rubi) and raspberry beetle (Byturus tomentosus)

The raspberry beetles eat leaf and flower buds. The Strawberry Blossom Picker is after strawberry blossoms. A broth of tansy is helpful against both beetles at the following times:

  • in spring at the time of budding or flowering
  • in the fall after harvest
Raspberry Beetle (Byturus tomentosus)

Fleas (Psylliodes)

Flea beetles are small leaf beetles that can cause great damage to seedlings and young plants by eating leaves. Inject tansy tea or broth twice a week for prevention. In case of emergency, pour with the broth.

Colorado potato beetle (Leptinotarsa decemlineata)

Colorado potato beetles eat the leaves of potato plants, which leads to the death of the plant. A proven measure against the beetles is to put tansy next to potatoes. Because Colorado potato beetles the smell deters the beetles.

mites

Strawberry mite (Tarsonemus pallidus fragariae)

Combat:

  • Sprinkle top and bottom of leaves with tansy tea
  • several times at intervals of three to four days
  • begin in May at the earliest
  • spray again after harvest
  • Minimum temperature: 10 degrees Celsius

Bramble gall mite (Acalitus essigi) and raspberry leaf mite (Phyliocoptes gracilis)

  • After cutting, spray in autumn (once) and in spring (twice) with tansy tea plus algae lime
  • Use broth in spring and autumn, if necessary dilute with twice the amount of water

Currant gall mite (Cecidophyophis ribis)

  • Spray tansy broth undiluted in winter and spring
  • Dilute broth for post-flowering spray once or twice
  • Spray tansy tea before and after flowering

Fruit tree spider mite (Red spider, Panonychus ulmi)

Fruit tree spider mites affect a number of fruit varieties such as

  • Apple
  • pear
  • currant
  • orange
  • gooseberry
  • plum

A broth made from tansy is used against the plague in spring and autumn.

Root mites (Rhizoglyphus sepc.)

If you notice eating meal when storing tubers, dip the bulbs and tubers in tansy tea for 30 minutes.

The preferred host plants are:

  • Lilies, especially leeks (Allium) or lilies (Lilia)
  • freesias
  • hyacinths
  • gladioli
  • potatoes
  • carrots

mushrooms

American gooseberry powdery mildew (Sphaerotheca mors-uvae)

The American gooseberry powdery mildew affects not only gooseberries but also currants. To protect the shrubs

  • mulch with tansy
  • spray a tea mixture of stinging nettle, tansy and field horsetail before they sprout

Powdery mildew (Erysiphaceae)

Powdery mildew fungi attack many ornamental and crop plants. Against the mushrooms comes tansy

  • preventively used as a broth
  • as a tea for injecting infected asters and phlox

plant lice

Aphids (Aphidoidea)

In view of the 800 species of aphids that occur in Central Europe alone, hardly any plants are spared from the pests. Against the plague helps:

  • Control: spray with tansy tea
  • defensive measure for trees: place tansy branches on tree discs

Scale insects (Coccoidea)

Scale insects infest a variety of plants, such as

  • Aralia
  • Figs (Ficus)
  • oleander
  • orchids
  • Palm trees

If you find an infestation, you can fight the plague with a broth made from tansy by spraying the plants with it.

Notice: Since scale insects sit on the underside of the leaves, it is particularly important to spray these plant lice.

root lice

So-called root aphids live in the root area of plants, although they belong to the aphids. Helps against the plague

  • in the bed: Water plants in the root area with tansy broth
  • Potted plants: Expose the root area and water several times with the broth (20 grams per liter) or immerse the roots.

Butterflies (Lepidoptera)

cutworms

The caterpillars of various cutworm species are referred to as cutworms. They feed on the roots of many crops. Helps against the caterpillars:

  • if infested: spray plants with tansy tea or water with tansy broth
  • preventive: immerse young plants in a broth of tansy

Flying butterflies

Using a broth of tansy has a deterrent effect

  • Codling moth (Cydia pomonella)
  • Winter moth (Operophtera brumata)
  • Cabbage White (Pieris brassicae)
Codling Moth, Winter Moth & Cabbage White (from left to right)

frequently asked Questions

Does tansy also help against mites on gooseberries?

Tansy tea is suitable for splashing gooseberries. Use the tea in spring and autumn.

Can I use tansy all year round?

Since tansy tea (broth, manure) also kills beneficial insects, you should not use it as a preventive measure all year round. However, if an infestation occurs, you can use natural plant protection at any time, regardless of the season. This is especially true for aphids, cutworms and root lice.

How long does tansy stock keep?

Rainfarnsud, often also referred to as tansy tea, can be kept for a few weeks. Store the brew in a cool place. It is ideal if you fill the tea in dark bottles.

Category:

Garden pests