beware pyrethrum sprays

 In early spring my Mum enjoyed the butterflies frolicing among the spires
of colourful blooms on her snapdragons. Then she realised it was not the
nectar they were coming for--the blossoms were being shredded by hundreds
of caterpillers! Not the leaves, just the delicate blooms.

So I sprayed the flower heads with a ready-to-go pyrethrum spray. Two
days later the blooms had turned brown, burnt by the spray! So she cut
off all the flower heads and hoped that more would develop. But ten
days later the spires of leaves showed severe burn and the plants had
to be cut back to near ground level. Maybe there is still a chance they
will reshoot this season.

I didn't see any warning on the pack label that plants could be burnt
by it. I did apply it generously hoping for a quick kill, but didn't
read any caution about being heavy handed. So be warned.

I've suggested Dipel or Success for future combat.
--
John Savage                   (my news address is not valid for email)

 Do you use the spray during the day?

I used a similar spray and it ended up burning my roses - but it was on
account of the sun's heat. If I had done it in the evening or very early
morning it doesn't happen.

BD

 Maybe you burnt them due to the gas being a sort of refrigerant. In
other words youre spraying a bit too close to the plants.
Do it when there is no winf ie early in the morning when theres very
little wind. Then you can spray them with some distance in between.

Blackadder wrote:

 anotehr to consider jonno,

when i used to spray i always did so after the heat of the sun, in the
afternoons or early evenings.

and aerosol cans carry the added down side that the propelants could
cause plant damage.

On Thu, 06 Dec 2007 22:30:16 +1100, Jonno snipped
With peace and brightest of blessings,

len & bev

--
"Be Content With What You Have And
May You Find Serenity and Tranquillity In
A World That You May Not Understand."

http://www.lensgarden.com.au/

 Thats what I meant to say Len, The propellant is a gas, (butane I
believe) and that when its released acts as a refrigerant, It cools
things donw rapidly. Same as filling a gas bottle, you see frost form on
the surface. IE can cause cold burns on plants. The same as heat burns.
Whether there is a difference in early morning or late spraying, I  dont
know...

len garden wrote: