Hyacinthus 'Woodstock' has spikes of fragrant, warm grape purple flowers.

Hydrangea integrifolia is a rare evergreen climbing hydrangea from Taiwan and the Philippines.

Hydrangea quercifolia 'Gatsby Pink' is an oakleaf hydrangea forming creamy white cones that flush to pink and turn to dusky pink to lavender-pink with age.

Hydrangea quercifolia 'Sikes Dwarf' is a compact oakleaf hydrangea with fragrant, conical flower heads of white with pink overtones.

Hydrangea quercifolia 'Toy Soldier' is a compact oakleaf hydrangea with a profusion of upright white to green conical heads.

Hymenocallis (Ismene) 'Advance' resembles a spidery, white daffodil with a round corona, long, thin filaments, yellow stamens, a greenish yellow throat, and stubby, narrow petals.

Imperata cylindrica 'Red Baron' is one of the most dramatic of grasses with brightly coloured red and green foliage.

Ipheion uniflorum 'Alberto Castillo' is a choice cultivar with larger, white, star shaped flowers scented of violet.

Ipheion uniflorum 'Tessa' has lavender-pink flowers with deeper-coloured midribs with yellow centres and sweet fragrance.

Ipheion uniflorum 'White Star' has pure white star-like flowers with a greyish-white central midrib on each petal which surround yellow centres and sweet fragrance.

Ipheion 'Jessie' is the darkest blue of the starflowers with sky blue to mid blue petals with a central royal blue stripe.

This Ipheion mix offers shades of blue, lavender-pink and white all with a sweet fragrance.

Iris chrysographes 'Black Form' has pure black iris flowers.

Iris ensata Dinner Plate 'Blueberry Pie' has large, 6 inch wide, purple blooms with violet strokes and yellow centres.

Iris ensata Dinner Plate 'Cupcake’ has white flowers with delicate purple and yellow centres. Blooms can reach 6 inches wide!

Iris ensata Dinner Plate 'Eileen's Dream’ has rich, warm purple, double flowers accented with yellow signals.

Iris ensata Dinner Plate 'Harlequinesque’ has flamboyant white flowers splashed with fuchsia and blue with yellow throats.

Iris ensata Dinner Plate 'Ice Cream’ has periwinkle-blue flowers with white margins. Blooms can reach 8 inches wide!

Iris ensata Dinner Plate 'Jell-O' has large, 6 inch wide, double purple blooms with white veining and yellow centres.

Iris ensata Dinner Plate 'Tiramisu’ has large, 6 inch wide, double white blooms speckled and edged in lavender with yellow centres.

Iris ensata 'Gold Bound' is an elegant Japanese iris with large, pure white, open-faced flowers with flashes of yellow.

Iris ensata 'Queen's Tiara' has pure white falls detailed with fine, purple veining and short purple standards.

Iris ensata 'Rose Queen' is a beauty with elegant, lightly blousy falls in shades of pink, lavender-pink, lavender, and dark pink with a flash of yellow.

Iris foetidissima is an evergreen, shade tolerant species with pretty flowers and dramatic displays of orange seeds in autumn.

Iris foetidissima 'Citrina' is an evergreen, shade tolerant species with pretty pale yellow flowers and bright orange seeds in autumn.