You can dry it by hanging it (like flowers) or you can just let it dry in your vase. If you let it dry while in water, there is a higher chance that it will discolour and turn brown so I usually dump the water out of my vase when the eucalyptus starts to look a little dry. That said… it doesn't always dry beautifully.
How long does seeded eucalyptus last?
Seeded Eucalyptus is grown outside and may have some naturally occurring blemishes. Expected vase life is an average of 8 days with proper care and handling.
How do you preserve seeded eucalyptus?
Store the eucalyptus in a dark, cool, dry spot to let it preserve. Make sure that it's not in direct sunlight. The eucalyptus will take two to six weeks to fully dry. You'll want to check on your eucalyptus every few days.