Blue Gum Eucalyptus Seeds

Description

• Blue gum seeds are easy to find because they are preceded by masses of pompomlike, creamy yellow flowers. The seed capsules form at the base of the flowers, where they stay after the flowers fade and fall away. They are roughly 1/4 to 1 inch in diameter with a conical shape and a crisscross indentation on the flat end. When newly formed, the seed capsules are waxy with a bluish color but they will turn woody and brown as they mature and dry out.

Gathering Seed

• Blue gum trees fruit in summer, although the seeds take several months to fully ripen and should not be gathered until later in the year. Most of the seeds will ripen roughly 11 months after the capsules form, although it may be sooner or later, depending on the climate. Gather them before the crisscross indentation at the end fully splits open, but after the hull has completely dried out and turned brown. Avoid immature seed capsules that still have their bluish, waxy hull.

Processing Seed

• Although the capsule might be mature, blue gum seeds need more time to ripen before they can be safely stored and germinated. Place the seed capsules inside a pillowcase or paper bag and set them in a warm, dry place outdoors to dry for one week. Shake the bag periodically to remove the seeds from the capsules. Ripened blue gum seeds are dark brown with a slightly rough or wrinkled seed coat. Discard any seeds with obvious problems, such as discoloration, holes or moldy spots.

Seed Storage

• Blue gum seeds remain viable in short-term storage if they are kept in an appropriate container under the right conditions. Any airtight container will work as long as it is clean and dry. The seeds may harbor insect eggs and should be stored with a mothball containing paradichlorobenzene, which will repel and kill most insect pests. Keep the seeds in a cool, dry area out of direct sunlight. A linen closet works well. Healthy blue gum seeds will germinate reliably for up to 10 years if they are properly stored, although they become less viable over time.

Germination

• Summer is the best time to germinate blue gum seeds, although they must first be chilled at 40 degrees Fahrenheit for two months to break their dormancy. The seeds require light to germinate, so cover them only with a scant layer of sand. Because the seeds are surface-sown, they must be watered using a spray bottle to keep from washing them away. Healthy blue gum seeds will sprout in two to four weeks if they are kept at temperatures of 70 to 85 F, at which point you can move them to a sheltered area outdoors. Blue gum eucalyptus is considered invasive in some areas, so check before you try to propagate it.