How to grow waratahs

In the small country town of Robertson in the Southern Highlands of NSW, there’s an unlikely friendship growing between vintage trains and classic Aussie flower, the waratah. Graham explores the Robertson Heritage Railway to find one of the best display of waratahs in the country. Spectacular in bloom with its sweet signature cherry red big plump flower heads, it was proclaimed the official floral emblem of New South Wales in 1962. Through natural selection and breeding programs, today we enjoy endless variations and personalities with never seen before colours, like the rare whites and yellow. Every bloom produced is a masterpiece of nature!

WATCH: Graham explores waratahs at the Robertson Heritage Railway

This magnificent native flower is recognisable to most Australians, with its most well-know type being the Telopea speciosissima, the New South Wales waratah, and its hybrid forms. Given the right conditions, waratahs are a hardy and reliable plant. Check the labels of the plants you buy for any special requirements. There are a number of general rules of thumb that apply to all species.

How to grow

Position

Part sun is best as only a few waratahs tolerate full or afternoon sun. Protect from wind. To ensure good airflow around plants, avoid crowding.

Soil

Waratahs thrive in free-draining, preferably slightly acid soil, with material such as a leaf compost blended in. Don't plant into clay soil as they won't tolerate wet feet. Instead, create a raised planting mound with a suitable soil, or grow in a large pot.

Climate

Waratahs enjoy a sunny spot in the garden away from wind.

Care

Keep waratahs moist but not wet during hot or dry periods. Mulch well with an organic material such as a leaf litter. Waratah's can be know to rot without proper drainage, be sure to also avoid root disturbance.

Keep your eyes out for pests, specifically the macadamia nut borer which appears in autumn to eat its leaves.

Pruning

After flowering, trim the canes back by half their length or three quarters. Established plants can be trimmed back to the swollen base of their trunks, called a lignotuber, to bring on new growth.

Once your plant reaches 10 years old cut back the canes completely to the lignotuber (swollen base).

Watering

Start watering waratahs in spring and stop in late autumn making sure to avoid watering in winter when the shrub is dormant. To reach their full potential waratahs need plenty of water during their growing people (spring and summer) paired with low phosphorus native plant food.

Size

Waratahs need room to strech out their roots and with the right care, waratahs can grow up to the towering height of four metres and three meters wide.

Planting

Rather than digging a large hole and filling it with plating mix or your waratah (which will slowly drown it) be sure to thoroughly dig over the soil and add leaf mulch over the are and in the hole instead.

Varieties

There are several magnificent varieties of waratahs including Brimstone Starfire which can only be propagated by stem cuttings. Another is a yellow form of the Tasmanian waratah crossed with a New South Wales type. The hybrid varieties are more adaptable.

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