Name: Dr. David
My wife and I have been trying to preserve thistles
for decoration at Highland (Scot) gatherings, which can be taken home by
those who are likeminded in our passion for the beautiful thistle.
Alas, to date we have not succeeded. Can you offer any insight into
effective preservation of the harvested plant, both the foilage and
preventing the head from bursting. It remains strongheaded even after
being lopped off and continues it's goal of reproductive effort.
You can find many methods of preserving plants, leaves, flowers and the
like by doing a search on the term(s): "preserving flowers", "dried
flowers", and similar terms. I used the search engine: www.google.com and
got a lot of different methods.
One way is the "bury" the specimen in sand to let it dry out, using
paraffin, dehydrating with silica gel. The object is to dehydrate the plant,
flower, seed pod etc. so that it can no longer reproduce. Some of these
sites provide detailed instructions and places to obtain supplies.
If you do not find anything satisfactory by doing such a search, try a local
flower club, horticulture society, botany department at a local college or
university, or even a museum. I am sure there are many resources with
regarding what you are trying to do. It is just a matter of getting in
I have had success preserving cattails, that is,
preventing them from breaking down according to normal
seed dispersal, by using either a clear coat of spray
paint or a lightly applied coat of polyurethane. The
product you choose is applied after the plant has
dried but before there is the beginning of any
breakdown of the seed head. (This is a challenge in
our area as gold finches are on the thistles as soon
as the seeds have matured, for a quick meal)
Once the dried thistles are coated, you should set
them wet side up in an area where the upper side can
dry. A similar coating is later done on the other
Note that using either product will alter the normal
appearance of the plant for display purposes, and, in
my experience, the specimen is likely to attract dust
which must be "carefully" removed in order not to
damage the preserved plant material.
For drying of the material, I have seen the use of
microwave for VERY BRIEF (perhaps 10 seconds or less)
times where the plant material is pressed between
NON-METALLIC pressing medium. You would have to
experiment with various microwave times and pressing
media to establish what best produces the effect you
are seeking. You must be careful not to exceed very
short microwave times so as not to damage your
Once dried, the clear coat spray paint or the
polyurethane should provide the preservation you seek.
Good luck, and thanks for using NEWTON!
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Update: June 2012