The herb feverfew (tanacetum parthenium) is traditionally used to prevent headaches, particularly migranes and my lovely partner in the sustainable life has suffered from that affliction for many years. Thus, when I found out about feverfew we planted some in the front garden. However, in my researches I have found out recently that feverfew flowers also contain pyrethrum and can be used as an insecticide. I do love plants that have multiple uses!
The process to make then usable as an insecticide is very simple –
1. Gather the flower heads - In the morning, cut the flower heads from the flower stalks, evidently the flowers contain more of the active principle in the morning. I just used a pair of household scissors to remove them from the parent plant.
2. Dry the flower heads – I did this by getting my low tech food drier and placing some insect screen over the drying rack to support the flowers. I then set out the cut flowers on the screen so that they were not touching each other. It was easiest to place any remaining flower stalk through one of the holes in the insect screen. This was a fiddly job, but did not take too long and ensured quick drying of the flowers.
Once the drier was set out with the flower heads I placed it on our back deck in the sun, to dry. In reality they probably took half a day but to ensure that they were fully dry I left them in the sun for the whole day.
3. Grind the Dried Flowers to Powder – I’m sure there are a number of ways to achieve this such as using a spice grinder or whatever, but I elected to use my mortar and pestle. This was quite easy and was just a case of placing a small amount of flowers into the mortar and then, over 5 minutes or so, grinding them up to a fine powder. The trick is to not overload the mortar and grind a small amount at a time rather than get lazy and try and do the whole lot in one go.
4. Pack off – the powder is now ready to use so pack it off into an airtight container and label.
To Use
Feverfew powder can be used in any situation where a broad spectrum insecticide is needed but be aware that while it is short lived in activity, it is toxic to beneficial species as well as the nasties, just like any pyrethrum insecticide.
The powder can be used as it is by dusting areas which have insect problems such as fleas in carpet or furniture or chook bedding if there is a mite or lice problem. It can also be used on pets directly as a flea powder.
By placing the powder in a “puffer” bottle it can be applied directly to plants or it can be mixed with water to form a “tea” and applied as a spray.
