AUTUMN colour is one of the joys of highland gardening, but anybody can create their own autumn foliage for flower arrangements by preserving leaves in a mixture of glycerine and water.
Picked and glycerined while plants are in active growth, leaves will turn from their natural colour to beguiling shades of tan, brown, red and purple as the glycerine gradually replaces the moisture in the leaves.
Foliage treated in this way become slightly glossy and looks amazingly lifelike and natural. It also lasts indefinitely.
Evergreen and deciduous leaves can be glycerined successfully, also some flowers and seed heads.
All you need to get started is glycerine ($4 per 100 millilitre bottle from pharmacy or health food store), some fresh leaves and a large container that’s can carry one metre long branches.
Leaves need to be as full of water as possible before you begin, so collect branches first thing in the morning and soak in a bucket for a few hours. A couple of three-centimetre slits in woody stems will assist absorption.
Glycerine is too thick and viscous to be absorbed as is, so needs diluting at the rate of one part glycerine to two parts water. Tough leaves like laurel, camellia and evergreen viburnum may require a half and half mixture.
Use almost boiling water and stir well or the glycerine will sink. Fill the container to about 10-15 centimetres, immerse the branches and put in a dark, dry place.
The time it takes foliage to absorb the maximum amount of mixture depends on the species: last March my red oak leaves took a fortnight.
Leathery evergreens can take eight or nine weeks, though strangely enough tough old eucalyptus takes only about a week.
Leaves are ready when all of their original colour has gone. Check regularly: sometimes you can see the colours changing as the glycerine progresses through the plant.
Don’t leave foliage longer than necessary or it will start dripping. On the other hand if it begins wilting after removal from the solution, hang upside down and gravity will do the rest.
Left-over solution can be re-used, but add half a teaspoon of disinfectant to prevent mould.
You absolutely must pick leaves while the sap is rising, so start thinking now about what you’d like to preserve this summer and collect it within the next couple of months and well before the onset of autumn colour.
Inside branches are better than outer ones as they are less likely to be damaged or discoloured. Good evergreens for preserving include spotted laurel, box, cotoneaster and the incomparable leaves of Bull Bay magnolia.
Attractive deciduous leaves include pin, scarlet and red oaks, maples with attractive fruit such as box elder maple and sycamore and hornbeam.
