Preserving Flowers with Glycerine

This method is more suitable for foliage than flowers, but certain flowers with “bracts” (modified leaves), such as Hydrangea and Molucella laevis (Bells of Ireland), will glycerine well. Grasses are also very successful, as is Gypsophila and Alchemilla mollis. Conifers also produce some lovely results.

Evergreens can be preserved all the year round, as long as they are kept reasonably warm, but deciduous material should be preserved between the end of June and mid-September. New spring growth will not take up the solution, nor will leaves which are turning colour in Autumn (Fall). Foliage should always be mature when preserved.

The colour of foliage preserved in glycerine is usually brown, but different types of plant material will glycerine to different shades of brown, from straw colour, through olive, to tan to nearly black, and every shade in between! The time of year that material is glycerined, and the light levels will also make a difference to the finished colour. For example, Beech leaves will preserve to a different brown when glycerined in July, than they will in August, and if they are kept in the dark whilst being preserved, they will turn a deep olive colour, but if done in light, they will turn tan colour. Experimentation is the name of the game! Laurel, White Poplar and Garrya elliptica leaves all turn black when glycerined, which is a lovely contrast in colour, from, for instance, Molucella laevis (Bells of Ireland), which turn very pale straw colour. One way to test what colour foliage will turn when glycerined is to pick a leaf and allow it to dry naturally. Whatever colour it goes will be roughly the colour it will turn when preserved. Autumn is the best time to observe this process, as the results are more accurate.

Pick your foliage, and remove any damaged leaves, as these tend to show up even more when glycerined, and is a waste of glycerine! Cut the stems at an angle, and split woody stems about an inch up the stem. It is important to condition your plant material before glycerining to be sure they are drinking, as the glycerine solution is thicker than water, and will often clog stems, resulting in wilting. Place the stems in warm water, and let them drink for a couple of hours, or preferably overnight, before placing in the glycerine solution.

To make the glycerine solution, mix two parts very hot water with one part glycerine and stir thoroughly. Hot water must be used as glycerine is heavier than water, and will sink to the bottom if cold water is used. Allow the mixture to cool off until it is just warm before use. **SPECIAL NOTE – The solution can be re-used time and again. Just sieve it through a fine sieve (or a pair of old tights!) to remove any debris, and re-use it or add it to a fresh batch. Although it turns brown after use, this is perfectly normal, and won’t affect the finished results.**

Once conditioned, place the stems in the glycerine solution. The time it takes to preserve the plant material very much depends on what type of plant material is being used. Some things such as Cotoneaster horizontalis will be ready in about 30 hours, whilst things like Aspidistra elatior may take two or three months! Check the material daily, you will be able to see the brown glycerine solution being taken up the veins of the leaves, and when it reaches the top, it’s done! Don’t allow material to stand in the solution any longer than necessary, as this will result in the glycerine “bleeding” from the leaves, and this can cause a black sooty mould to form, as well as being very messy…..