Olearia axillaris – Coastal Daisy Bush Growing Guide

Getting to Know Olearia axillaris

Prized for its eye-catching foliage and useful form, this hardy shrub offers growers many ornamental and practical landscaping applications. Its overall form is dense and compact, featuring branchlets that are aromatic and narrowly lanceolate with attractive egg-shaped edible leaves.

I’ve covered countless Australian native shrubs but this species is honestly a thing of beauty and elegance within gardens. Forming a part of the Olearia genus, species axillaris, the plant is also a part of the daisy family, Asteraceae. It is endemic to many of the coastal regions of continental Australia. 

Its common names include wild rosemary and the coastal daisy bush, the latter of which refers to the shrub's delicate daisy-like flowers which are also edible to some extent. Regarding its preferred climates, it is a very hardy and adaptable species that can suit most Australian conditions. 

However, it cannot tolerate extremely cold or wet conditions. Within gardens, this evergreen shrub is considered fast-growing, typically reaching about 1 to 3 metres tall and wide.

Landscaping Applications with Olearia axillaris

The plant offers a wide variety of uses within residential gardens, regardless of their size. It is most commonly used in group plantings for gap-filling purposes but it can also be used as a feature specimen in smaller spaces. 

Moreover, its growth habit makes it ideal for use as a screening or hedging plant. (See our roundup of Australian native hedging plants for a wide variety of options.)

Additional planting benefits include excellent soil erosion control and naturally, this seaside species is a perfect addition to coastal gardens. Lastly, if you lack the proper space in your garden beds, coastal daisy bushes can be reliably grown in pots.

How to Grow Olearia axillaris

Propagating Olearia axillaris

Propagation of this species can be reliably carried out using seed or stem cuttings. Seeds can be collected from the ripened achene fruits after flowering or more viable seeds can be purchased from reputable online seed vendors nationwide. 

Cuttings should be taken from a healthy parent plant and can be taken at any time of the year.

Propagating Coastal Daisy Bush from Seeds

• Sow seeds in spring or autumn in temperate climates to avoid overly hot or cold conditions.
• Prepare seed containers by filling them with a quality porous seed-raising mix.
• Surface sow the seeds then mist to help them lodge themselves into the mix.
• Sprinkle a light layer of seed-raising mix over the seeds if required to hold them in place. Avoid burying seeds deeply.
• Place the seeds in a warm shaded or semi-shaded location. 
• Mist as needed to keep the soil warm and moist but try to avoid allowing the mixture to dry out or waterlogging the growing mix.
• Ideal germination temperatures are around 15°C to 20°C.
• Germination should occur within 14 to 42 days in good conditions.

Wild Rosemary Propagation Using Cuttings

• Using sharp and sterile pruning shears, take healthy stem cuttings from the parent plant that are at least 10 to 15 centimetres in length.
• Prepare containers filled with a quality propagation mix or potting soil then water very lightly to make the soil slightly moist before planting. 
• Remove some of the foliage from the bottom section of the cuttings (5cm or so) then dip the cuttings into some rooting hormone for edible plants. Then, plant the cuttings directly into the mix. 
• Place the cuttings in a warm and sheltered location that gets some indirect sun and shade. Ideal temperatures for cuttings are around 20°C to 22°C. 
• Water as needed to keep the soil moist but never wet. 
• Allow cuttings to establish themselves properly before transplanting. They usually root within 4 to 6 weeks.

Planting and Growing Conditions for Olearia axillaris

As mentioned, this shrub is a great soil-binding species that can be used in many different positions in gardens so long as its basic growing conditions are met. 

Preferred Sun Exposure

This plant requires full sun positions to thrive and look its best throughout the year. Try to position your shrub in a spot that gets as much full sun as possible. This will ensure the foliage remains vibrant year-round and that the blooms are as prolific as possible.

Ideal Soil Conditions for Olearia axillaris

Coastal daisy bush will thrive in light to medium well-drained soils. While it can tolerate different soil types, it prefers sandy or sandy-loam soil in gardens. 

Boosting Soil Before Planting

If you have denser, heavier soil than that mentioned above, you can help boost the viability of your soil by thoroughly digging in some sand or loam soil before planting. This will help to ensure adequate drainage and soil moisture levels. 

Quick Tips for Growing in Pots

• Always use well-draining containers filled with quality and well-drained potting mix.
• Prune potted specimens frequently to maintain shape, size and tidiness.
• Potted plants usually require more frequent watering as well. 
• Place your potted shrub in a position that still gets as much full sun as possible.

Caring for Olearia axillaris

Once established, this species is tolerant to drought, fire, wind and salt but is only moderately tolerant to frost. This is why overly cold and wet environments are not suitable.

Apart from that, this native requires only basic care to thrive, offering growers a showy but low-demanding addition to their outdoor spaces.

Watering Needs

Water well after planting until established then minimal supplemental waterings are required. On average, water about once a week in normal conditions and perhaps twice weekly in overly dry and hot conditions. Cut back water in winter.

Pruning Coastal Daisy Bush

This particular species responds extremely well to pruning, hence its excellent hedging and screening abilities. It is encouraged to lightly tip prune regularly throughout the year to maintain a tidy and dense habit. Alternatively, prune more heavily each early spring for a more untamed appearance. 

What Fertiliser to Use

Feed with a high-quality native plant fertiliser in spring and autumn to encourage new vigorous growth and more prolific flowering. Try to use an organic fertiliser for the best results.

Mulching 

You can optionally add a light layer of organic mulch around the base of the shrub in summer to assist with moisture retention and suppress weeds. Mulching is particularly useful in soils that drain very fast.

Pests, Problems and Diseases

Luckily, this is one of those few native species that is very resilient to pests and diseases. In fact, there is hardly any information available that suggests that any pest or disease issues plague this genus and species.

Wild Rosemary Bush Tucker Guide

As mentioned earlier, this bush tucker produces edible leaves and flowers. However, it’s the leaves of Olearia axillaris that are particularly useful in the kitchen.

Early European colonists would go on to suggest the common name, wild rosemary, while also finding the plant to be very similar to that of English rosemary in both its appearance as well as its flavour profile.

Wild rosemary leaves offer a homely and grassy-like smell and flavour profile, perfect for use as a flavourful herb or spice in the kitchen. Traditionally, the leaves were crushed by Indigenous people and then used as an insect repellent or used as a flavoursome herb for cooking.

The shrub’s small cream-coloured flowers are also edible but are mainly used for their decorative characteristics.

Harvesting Wild Rosemary

You can cut off whole stalks as needed from mature plants and then use the sprigs fresh or, chop the leaves and dry them for use at a later time. Dried leaves can also be crushed for use as a herb or seasoning.

Just keep in mind that the strength of the aroma and taste of bushfood herbs tend to fade over time so using them as soon as possible will allow you to reap the full experience from the leaves in the kitchen. 

As a safety precaution, always delay harvests for a few days after fertilising before consuming any bushfood. 

How to Use Wild Rosemary

• The sprigs and leaves are commonly used both fresh and dried to flavour a wide variety of sweet and savoury dishes. 
• Use wild rosemary like normal rosemary to flavour a wide range of meat-based dishes, soups, stews, salads, pestos and much more.
• The sprigs are also especially nice to use on the barbecue.
• You can also dry the leaves and use them as part of a seasoning rub or coating to flavour roasted meats, veggies and even your favourite pizza.
• Lastly, try a small sprig as a garnish in your favourite gin or cocktail.
• The flowers can be used as attractive garnishing for aesthetic platings or decorative cakes and desserts.
• The possibilities are almost limitless with this delicious herb so be sure to experiment and find your favourite configurations in the kitchen.

Olearia axillaris Frequently Asked Questions

How tall is Olearia axillaris?

Being one of Perth’s most vigorous and iconic coastal shrubs, this silvery species is considered fast-growing and typically reaches a maximum height of up to 3 metres in gardens.

What are the uses of Olearia axillaris?

This species is primarily used as a foliage plant that is highly useful for group plantings, hedging and screening, or as a gap-filling feature plant. Its large silvery fronds can offer a highly ornamental influence to your outdoor spaces throughout the year.

How do you propagate Olearia axillaris?

Like most species in the genus, this shrub can reliably be propagated using healthy stem cuttings. 

Can you grow wild rosemary indoors?

It is usually recommended not to grow grey-foliage plants or shrubs indoors as they need full sun to ensure vigorous growth and striking colour in their foliage. This species does and looks its best outside in the garden, positioned in a sunny spot.

What is the common name for Olearia axillaris?

The plant is commonly known as Coastal Daisy Bush or Wild Rosemary, the latter of which is more commonly used in bushfood terminology. 

Is Olearia axillaris an evergreen?

Yes, the plants in this genus are fast-growing and vigorous evergreen flowering plants. They are considered hardy, and suitable for windy and exposed coastal sites.

Looking to add other silvery specimens to your outdoor spaces? Check out some of our favourite white to grey-foliage plants below:

• Dichondra Silver Falls
• Rose Mallee (Eucalyptus rhodantha)
• Flannel Flowers