Silva Sulfa Grevillea

Silva Sulfa Grevillea (Grevillea 'Silva Sulfa') is an Australian native shrub for the dry, difficult end of the garden. It builds to roughly 2m tall and 2m wide, carrying soft yellow and cream flowers that honeyeaters and wattlebirds work over daily. Once established it wants almost nothing: no irrigation, no rich soil, and no feeding beyond an occasional native fertiliser.

Why you'll love it

• Birds arrive within weeks. The nectar rich flowers pull honeyeaters into a garden that had none, which is why most people plant a grevillea.
• It thrives on poor soil. Sand, gravel and thin compacted ground all suit it. Rich, heavily improved beds shorten its life.
• Real drought tolerance. After two summers it holds condition through dry spells unwatered, which counts in arid and Mediterranean gardens.
• Coastal and salt tolerant. It handles exposed seaside blocks where most flowering shrubs burn off in the first strong southerly.

Where it works best

Screening and privacy. Plant 1.5m apart for a dense informal screen to around 2m. Grevilleas do not clip as neatly as a lilly pilly, so expect a softer, looser wall of foliage.

Mass planting. On a slope, a nature strip or a dry bank, groups at 1.5m spacing cover ground quickly and need no irrigation once away.

Coastal gardens and feature planting. It suits front line coastal positions, and works as a single flowering accent among rocks and grasses.

Growing Silva Sulfa Grevillea in Australia

Position and climate. Full sun, and plenty of it. Shade produces a thin, sparse plant with few flowers. It suits subtropical, warm temperate, Mediterranean and arid gardens, and it takes light frost only, so hard frosting inland and tableland districts are outside its range.

Soil. Free draining above all else. Sandy, gravelly and poor soils are ideal. On clay, plant high on a raised mound and open the bed with coarse sand or gravel rather than compost, because wet feet and root rot are what kill grevilleas.

Water and feed. Water weekly through the first summer, then only in extended dry spells. Grevilleas are sensitive to phosphorus, so use a low phosphorus native fertiliser in early spring and never a standard garden fertiliser or manure.

Pruning. Tip prune from planting and trim by up to a third after each flowering flush. This is the one job that matters: unpruned grevilleas go leggy and woody at the base within a few years, and do not always recover from a hard cut back.

What to expect when it arrives

This variety is grown as tubestock only, so plants arrive young, usually 15cm to 25cm tall with a well developed root system and no flowers. That is deliberate rather than a compromise. Tubestock grevilleas establish faster and live longer than pot bound advanced plants, because the roots have never circled.

Tubes travel well and should go into prepared ground quickly. Expect little visible growth for two months while the roots move out, then a strong flush, with real flowering in the second year. Delivered Australia wide, with delivery from $29.95 and a minimum order of $300 before delivery, and every plant carries our 30 day healthy plant guarantee.

Plant care guides and related reading

• The complete grevillea care guide
• Native plants with yellow flowers
• Compare varieties in the grevillea collection
• Browse more Australian native shrubs

Common questions

How far apart should I plant it for a screen?

One and a half metres apart in a single row. Grevilleas fill sideways more than upwards, so tighter spacing crowds the bases and thins the lower foliage.

Why is my grevillea yellowing and dying back?

Usually phosphorus or poor drainage. Standard fertilisers and manures poison them, and wet roots bring on rot. Switch to a native fertiliser and check that water drains away from the planting hole.

Does it need pruning to stay dense?

Yes, and it is worth the effort. A light trim after each flowering flush keeps the shrub compact and flowering heavily, while a neglected plant goes woody and bare at the base.