Blue rock bindweed (Convolvulus sabatius) is a fast growing perennial plant (annual in colder climate). This is a herbaceous trailing ground covering plant with woody base. The stem and leafs are hairy. Leafs are small, oval shaped with narrow tip, and arranged alternately.

http://icflora.blogspot.com/2017/12/blue-rock-bindweed-convolvulus-sabatius.html

Care
Once established this is remarkably low care plant. Best in full sun it will grow well in containers and hanging baskets as well.

Although it will tolerate dry soils, it performs at its best in a humus rich soil.

Dig a little compost through the soil. plant and water in with a liquid seaweed fertiliser. A little additional water through the first summer will assist with establishment.

Pruning
You can prune the silver bush back in early spring as new growth commences. We suggest a hard pruning every 3 years and a little light pruning every year just after flowering.

With silvery green foliage and white flowers, Convolvulus cneorum lives up to its common name of Silver Bush.

This is an easy care ground cover plant, evergreen, drought tolerant and it forms a small shrub or ground cover plant. The flowers have a buttery yellow eye and the foliage remains attractive year round.

This is a great plat for the dry garden border, use it as a filler, or plant it as a low border. You can also grow the Silver Bush in a container where it adds low maintenance colour.

Summary
Botanical Name – Convolvulus cneorum
Common Names – Silver Bush.
Position – Full sun to Part shade.
Soil – Humus rich, moist, well drained.
Height – Will reach around .6 metres
Spread – Will spread to around .8 metre.
Growth rate – Medium.
Foliage – Silvery green.
Flowers – White.
Flowering period – Summer to Autumn
Drought tolerant – Yes once established.
Frost tolerant – Yes.

https://www.nurseriesonline.com.au/plant-index/perennial-plants/convolvulus-cneorum/