How to Grow Australian Native Plants from Seed

Growing Australian native plants from seed is one of the most affordable and rewarding ways to fill your garden with beautiful Australian plants that look stunning and thrive in local conditions. Australian native plants are typically drought hardy (require less water than imported plants), easy to grow and adapted to tough conditions. However, their seeds can behave very differently from common vegetable or flower seeds.

Some native seeds like everlasting daisies (aka paper daisies) germinate easily. Others need special treatment first, such as soaking, hot water treatment and/or smoke treatment. This is because many Australian plants have evolved with fire, drought and seasonal rainfall as natural germination cues.

Why Australian native seeds can be harder to germinate

In nature, many Australian native seeds wait in the soil until conditions are right. For some species, fire is one of the signals that tells the seed it is safe to germinate. Research has found that smoke from burnt native vegetation significantly improves germination in a broad range of Australian native species.

Best seed raising mix for Australian natives

Australian native seeds generally do best in a free-draining seed raising mix. Avoid heavy, soggy mixes, because many native seedlings are vulnerable to rot when they stay wet for too long.

A good native seed raising mix should be:

• Fine enough for small seeds
• Free draining
• Low in added fertiliser
• Able to hold some moisture without becoming waterlogged

A mix based on coco coir, perlite, vermiculite and coarse sand can work well, depending on the species.

Growing Healthier Futures's seed raising mix is ideal for germinating Australian Native seeds, when combined with smoke or heat treatment where required. 

Do Australian native seeds need smoke treatment?

Some do. Many Australian wildflowers, grasses, trees and shrubs benefit significantly from smoke treatment. Smoke contains chemicals that can trigger germination, including a group of compounds known as karrikins. Studies have shown that karrikinolide, a smoke-derived compound, can stimulate germination in a wide range of plant families.

Smoke treatment can be applied using smoke water, smoked vermiculite, smoked seed raising mix or physically exposing seeds to smoke - although this comes with safety risks. For home gardeners, smoke water is often the easiest and safest option.

Growing Healthier Futures offers a liquid smoke treatment in easy to use small pump bottles on our "shop" page. 

How to use liquid smoke treatments to germinate Australian native seeds

For seeds that require heat and smoke treatment, dilute 1 part Growing Healthier Futures smoke water treatment with 10 parts almost-boiling water in a small mug or heat-proof container, and allow seeds to soak overnight or for 12 hours. We do not recommend allowing children to work with boiling water, for safety reasons. 

Then, sow your Australian native seeds as per the instructions on the packet. 

For seeds that do not require heat treatment, follow the same instructions above but with warm water. 

This smoke treatment method has been shown to be an affective way of breaking the dormancy of Australian native seeds that have evolved to be triggered by natural bushfire conditions.

How to sow Australian native seeds

Fill a clean seed tray or small pot with the seed raising mix referenced above. 

For seeds that benefit from smoke treatment, we recommend adding a thin layer of Growing Healthier Futures smoke-infused coco-coir to the top of your seed raising mix. 

Water it first so the mix is evenly moist. Sprinkle fine seed on the surface and only cover lightly if needed. Larger seeds can usually be pressed into the mix and covered to about their own depth.

Keep the mix damp, not wet.

Many Australian native seeds require sunlight to germinate, so keep your tray somewhere with plenty of direct sunlight like a north facing window til, outdoors in a protected space or under a full spectrum LED growlight inside.

Native seeds can take anywhere from days to months to germinate, so patience matters.

If your seeds haven't germinated within a few weeks, don't give up. Watering occasionally with diluted smoke water can boost changes of seed breaking dormancy.

Common mistakes when growing Australian natives from seed

The most common mistake is treating all natives the same. Australian natives are incredibly diverse. A paper daisy, a wattle, a kangaroo paw and a eucalyptus may all need different germination conditions. Paper daisies do NOT need smoke treatment, and in fact smoke treatment can reduce germination rates for some native flowers. 

Other common mistakes include:

• Not using smoke treatment on seeds that need it - Banksias, Hakeas, Anigozanthos (Kangaroo Paw), Grevillias 
• Not using heat treatment on seeds that need it - Acacias (Wattles)
• Using smoke treatment on species that do not need it - eg paper daisies (Xerochrysum bracteatum, Rhodanthe).
• Using rich potting mix instead of seed raising mix
• Burying tiny seeds too deeply
• Giving up too early
• Overwatering
• Letting soil dry out

Heat vs. smoke: they're not the same

It's useful to distinguish the purpose of each treatment:

Hot water / heat: Breaks a hard, waterproof seed coat so water can enter. 

Smoke: Provides chemical germination cues (karrikins) associated with fire 

Both: Some species respond to a combination of heat and smoke, but this is less common than either treatment alone

Final tip

Start with easier Australian native seeds first, such as paper daisies, kangaroo paws and some native grasses. Once you understand the basics, you can experiment with trickier species and pre-treatments.

Growing Australian natives from seed takes a little learning and bit of patience, but it is a brilliant way to create a cost-effective, resilient, stunning and wildlife-friendly garden from the very beginning.

References

Dixon, K.W., Roche, S. & Pate, J.S. “The promotive effect of smoke derived from burnt native vegetation on seed germination of Western Australian plants.” Oecologia, 1995.
Long, R.L. et al. “Detecting karrikinolide responses in seeds of the Poaceae.” Australian Journal of Botany, 2011.
Australian Native Plants Society Australia, “Smoke Germination of Australian Plants.”