Tanacetum Radiant Deep Pink has glowing magenta flowers with bright yellow centres on compact, upright plants.

Tanacetum Radiant Light Pink has glowing light pink flowers with bright yellow centres on compact, upright plants.

Tanacetum densum var. amani forms evergreen, textured mats of soft, feathery, silver foliage and bright yellow button-like flowers.

Thalictrum 'Black Stockings' is a Meadow Rue with large, flat topped fluffy clusters of lavender flowers on top of tall dark stems.

Thermopsis chinensis 'Sophia' is a lupin relative with canary yellow flowers blooming at the same time as tulips and daffodils.

Trifolium 4 Luck 'Coco Mint' is a darling little groundcover offering vigorous carpets of little shamrocks that are rich burgundy with mint green centres.

Trifolium 4 Luck 'Dark Eye' is a cool ground cover offering vigorous carpets of little shamrocks that are mint green with burgundy centres.

Trifolium 4 Luck 'Green Glow' is a darling little groundcover offering vigorous carpets of little shamrocks that are emerald green with mint green tips.

Triteleia 'Queen Fabiola' offers umbels of up to 25 funnel, star-shaped blue/mauve flowers on wiry stems.

Triteleia 'Rudy' offers umbels of up to 25 funnel-shaped, white flowers with a glowing purple stripe down the middle of each tepal.

Trollius 'Alabaster' has semi double, spherical, soft butter yellow flowers. Globe flowers are very hardy and easy to grow.

Trollius 'Lemon Queen' has spherical, golden yellow flowers. Globe flowers are very hardy and easy to grow.