Mimulus x hybridus ‘Bounty Red’ – This Monkey Flower is part of the Bounty Series (which also includes orange, rose and yellow) of perennial Mimulus generally grown from seed. They flower in their first year with brilliant red blooms (with spotted yellow throats) from June to July. It performs best in evenly moist soils. Grows 6-12″ high by 10-12″ wide. Hardy to zone 7.
Centranthus ruber var. coccineus – Also known as Jupiter’s Beard or Red Valerian, this old-fashioned cottage perennial bears fragrant deep crimson flowers (from June to August) that attract butterflies. It is more compact than the species and has greyish-green foliage. This species prefers alkaline soils and can naturalize from seed. Grows 24-30″ high by 18-24″. Zone 5.
Lychnis chalcedonica – Maltese Cross is an RHS Award of Garden Merit winner with domed reddish-orange flower heads from June to August. This species prefers part to full sun and may get a bit floppy when grown in rich soils or over-fertilized. It is a long-lived cottage garden perennial and is best place near the back of the border. Grows 3-4′ high by 18″ wide. Hardy to zone 3.
Penstemon ‘Firebird’ (syn. ‘Schoenholzeri’)- Another RHS Award of Garden Merit winner that came out of Switzerland in the 1930’s. It bears rich ruby red flowers (from June to August) with darker throat striping on white that shows well on mature flowers. The hummingbirds adore this plant and it is often evergreen in milder regions. Grows 2-3′ high by 24″ wide. Hardy to zone 7.
Helianthemum ‘Red Dragon’ – Sun Roses are small evergreen sub-shrubs that are often sold in the perennial section. ‘Fire Dragon’ bears papery deep red blooms with contrasting yellow stamens from May to early August. It is a little more upright than other Helianthemum cultivars and prefers full sun with well drained soil. Grows 12″ high by 18-24″ wide. Zone 4.