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Name: Dr. David
Status: other
Age: 50s
Location: N/A
Country: N/A
Date: 1999-2001 

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: 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 information regarding what you are trying to do. It is just a matter of getting in touch.

Vince Calder

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 side.

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 machine!

Once dried, the clear coat spray paint or the polyurethane should provide the preservation you seek.

Good luck, and thanks for using NEWTON!

Ric Rupnik

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