P -- good source of pollen
N-- good source of nectar
* -- excellent for bees

Ribes *NP Blackcurrant, and flowering currant, redcurrant, white currant, gooseberry.
Romneya coulteri *NP fragrant flowers of the tree poppy with huge white & and yellow flowers (up to 6" across) July to October.
Rosa P a remarkably easy rose to grow
Rosmarinus Officinalis *NP Rosemary. White through mauve flowers on this popular herb. Planted in Mediterranean gardens as a welcome to visitors.
Rubus *NP Blackberry, Raspberry, Bramble.

 

Salix *NP (especially S. alba) Willow. Important source of early pollen and nectar from the male flowers
Salvia NP commonly referred to as Sage
Saxifraga NP The Latin word Saxifraga comes from Latin saxum, "rock", and frangere, "to break". These plants are known for their ability to settle in the cracks of rocks.
Scabiosa NP Common Names are Small scabious and pincushion flowers
Scilla NP of bulb-forming perennial herbs in the Hyacinth family
Sedum *N Ice plant, Stonecrop. Tiny flowers borne in vast profusion, often late autumn and early spring. Important nectar source.
Sidalcea NP Sidalcea resemble miniature hollyhocks, with clusters of upright stems bearing pink mallow-like flowers from early to late summer. Common Name Checkerbloom
Skimmia NP The flower buds look like pink flowers and slowly develop during late autumn before finally opening to reveal the small white flowers in late winter.
Stachys NP Lambs' ears is a well-known ground-covering perennial, popular for its soft, fluffy foliage.
Stransvaesia *NP White hawthorn-like flowers in June, berries August/September.
Symphoricarpos NP common names in English are Snowberry, Waxberry. It is a member of the Honeysuckle Family
Syringia NP common name is lilac