How to Grow Eucalyptus Seeds
Grow Guide #2834
Family: Myrtaceae
Binomial name: Eucalyptus sp.
Life Cycle: perennial
This 'How to Grow' guide details everything a home gardener needs to know to plant, grow and care for Eucalyptus (Eucalyptus sp.).
When to Sow Eucalyptus Seeds
Eucalyptus is a perennial plant that grows year round in most climates. Use the table below to identify the best time of year to sow eucalyptus seeds in your climate.
JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Cool | ||||||||||||
Temperate | ||||||||||||
Sub-Tropical | ||||||||||||
Tropical | ||||||||||||
Arid |
Preparation
Eucalyptus plants are best grown in full sun. Choose a location that will receive at least 6 hours of full sun each day.
Eucalyptus plants are perennial, meaning they live for several years. Choose a permanent position where plants can grow undisturbed by regular digging.
Eucalyptus plants grow into large plants when mature. Ensure there is space for seedlings to be planted 200-500cm apart so they have space to grow to their mature size.
Eucalyptus plants need a well drained soil enriched with plenty of organic matter. Prepare soil by weeding it thoroughly, digging it over to loosen it and adding aged animal manure or compost. Keep the area free of weeds until planting. Learn more about preparing soil for planting here.
How to Sow Eucalyptus Seeds
Eucalyptus seeds do not require any treatment (eg soaking, stratification) before sowing.
Seeds may be mixed with chaff and the seeds and chaff can be difficult to tell apart. Sow seeds and chaff together.
Eucalyptus seeds grow best when they are raised in trays or other containers and transplanted to the garden once established.
- Fill trays, punnets or jiffy pots with a good quality seed-raising mix, or use soil starter pellets.
- Sow seeds 2mm deep.
- Keep soil moist but never wet or dry.
- Seeds should germinate in around 7-28 days at a soil temperature of 18-21°C.
- Transplant seedlings to the garden once they have their first true leaves and are large enough to handle (usually 5-10cm tall).
- Plant out, spacing plants 200-500cm apart.
Note: Seeds of many native plants are dormant and will not germinate until ideal environmental conditions are met. Follow instructions for pre-treatment and sowing, and be patient; some wild harvested seeds can take much longer to germinate than expected.
Tip: Eucalyptus seeds are quite small. Handle them carefully to avoid them blowing away or being washed away. Mix seeds with sand or fine potting mix prior to sowing or use a seed dispenser, damp toothpick or tweezers to help space them evenly. Press lightly into the surface after sowing so that the seeds make good contact with the soil. Take extra care to make sure seeds and seedlings don’t dry out. Read more about sowing small seeds here.
How to Grow Eucalyptus
Eucalyptus plants may need watering during the growing season. Water when the soil is dry about 5cm below the surface (test this by scratching away a little soil with your finger). Water deeply in the early morning or late afternoon. Avoid watering the leaves of plants to avoid fungal diseases. Learn more about watering here.
If soil was well prepared no extra fertiliser should be necessary. In poor soil or to give your plants an extra boost, application of a low-phosphorus fertiliser or one formulated for native plants can be beneficial:
- Apply slow release fertiliser at the recommended rate when transplanting or when seedlings are 5-10cm tall.
- Apply liquid fertiliser at the recommended rate and frequency while plants are fruiting or flowering.
If growing eucalyptus for cut flowers or foliage, use sharp snips or secateurs to cut branches of the desired length, removing the lower leaves and placing the stems immediately in a clean bucket of water. Learn more about cutting and conditioning homegrown flowers here.
Eucalyptus should reach maturity in approximately 5-20 years.
Common Problems when Growing Eucalyptus
Like all plants, eucalyptus is susceptible to some pests, diseases and other problems. Below is a list of the most common problems gardeners encounter when growing eucalyptus plants:
- Powdery mildew is caused by fungal spores reproducing on the leaves of plants. First showing as white spots on leaves, affected areas can spread quickly to cover the entire leaf surface. While rarely fatal, powdery mildew can reduce yields. Water plants at soil level (not on leaves) to prevent spreading spores, allow good air flow between plants, remove affected leaves and if necessary spray with an appropriate fungicide or homemade spray. Read more here about powdery mildew here.
- Root rot is a disease caused by soil-borne fungi found in wet soil. Plants may be slow to establish, have yellowing or wilted foliage and have soft, brown tissue around the base of the stem and roots. Root rot is often fatal; remove and dispose of affected plants. Reducing soil moisture, adding organic matter to the soil and making sure mulch doesn't touch the stems of plants may help avoid root rot.
- Myrtle rust (Puccinia psidii) is a fungal disease which affects eucalypts, bottlebrush, paperbark, lilly pilly and other members of the Myrtaceae family. Spores are spread by water, wind, insects and animals. Small purple dots appear on leaves, followed by bright yellow spores which fade to grey as they age. Use disinfected tools to prune off affected branches, or treat with an approved fungicide; repeat treatments are usually necessary.