| Description | Description | Month Flower |
| |
| NEPETA (Catmint) |
| |
| | Hairy, aromatic leaves. Spikes of blue, white, yellow or soft pink flowers. | 6-9 |
| |
| OENOTHERA (Evening Primrose) |
| |
| | Terminal racemes of yellow or pink, cup-shaped flowers. Some species bloom at night, some have coloured foliage. | 5-9 |
| |
| ONONIS (Restharrow) |
| |
| | Flowers pink pea-like, stems thorny, requires good drainage. | 6-8 |
| |
| ORIGANUM (Ornamental Oregano) |
| |
| | Small aromatic foliage with white, pink or purple flowers. | 5-9 |
| |
| PANICM (Panic Grass) |
| |
| | Tall prarie grass with long, wide panicles. | 8-9 |
| |
| PAPAVER (Poppy) |
| |
| | Perennial poppies of varying colours and sizes. | 4-10 |
| |
| PENSTEMON |
| |
| | Foxglove-like flowers in red, pink, white or blue. We have one of the largest collections in the country. | 6-10 |
| |
| PERSICARIA (Polygonum, Knotweed) |
| |
| | Spikes of red, pink or white flowers. Some species have good autumn colour. | 6-9 |
| |
| PHLOMIS |
| |
| | Sage-like hairy leaves, with whorls of hooded yellow or lilac flowers. | 6-10 |
| |
| PHLOX |
| |
| | Red, Pink, blue, or white showy, sometimes scented flowers. | 4-9 |
| |
| PHYSALIS (Chinese Lantern) |
| |
| | White flowers with yellow eye, orange-red lanterns in autumn. | 9-11 |
| |
| PHYSOSTEGIA (Obedient Plant) |
| |
| | Terminal spikes of white, purple or pink flowers on 4-angled stems with lanceolate leaves. | 7-9 |
| |
| PHYTEUMA (Horned Rampion) |
| |
| | Rounded clusters of violet-blue flowers with linear, basal leaves | 6-8 |
| |
| PLANTAGO (Plantain) |
| |
| | major | 6-10 |
| |
| PLATICODON (Balloon Flower) |
| |
| | Attractive, large campanulate, pink, white or blue flowers. | 6-8 |
| |
| POLYGONATUM (Solomon's Seal) |
| |
| | Arching sprays of white bell flowers, fruits blue-black. | 5-6 |
| |
| POTENTILLA |
| |
| | Single or semi-double red, orange or yellow flowers | 6-9 |
| |
| PRUNELLA (Self-heal) |
| |
| | Low growing with white or pale violet whorls of hooded flowers. | 6-8 |
| |
| PULSATILLA (Pasque Flower) |
| |
| | Leaves fern like, flowers nodding, cupped shaped, silky seed heads. | 3-4 |
| |
| RHEUM (Ornamental Rhubarb) |
| |
| | Large ornamental foliage with tall flower spikes. | 6-7 |
| |
| RUDBECKIA (Coneflower) |
| |
| | Large golden-yellow daisy flowers with a dark centre. | 7-9 |
| |
| SALVIA (Sage) |
| |
| | Spikes of blue, violet or purple flowers. | 6-9 |
| |
| SANGUISORBA (Canadian Burnet) |
| |
| | Cylindrical , errect spikes of creamy-white or maroon flowers on stems. | 7-10 |
| |
| SCABIOSA (Pincushion Flower) |
| |
| | Domed pincushion flowers of burgundy, violet-blue, or ivory-white. | 6-10 |
| |
| SEDUM (Stonecrop) |
| |
| | Flat flowerheads of white, pink, mauve or purple, loved by bees and butterflies. | 6-10 |
| |
| SIDALCEA (False Mallow) |
| |
| | Small spires of red or Pink mallow flowers. | 6-9 |
| |
| SOLIDAGO (Goldenrod) |
| |
| | Loose sprays of small bright yellow flowers. | 7-9 |
| |
| STACHYS (Lamb's Ears) |
| |
| | Low growing with silver-grey, felted foliage. Some have showy flower spikes. | 7-8 |
| |
| STIPA (Feather Grass) |
| |
| | Dense clumps of narrow leaves with large loose panicles of dainty plumes. | 6-9 |
| |
| STOKESIA (Stoke's Aster) |
| |
| | Aster-like flower heads of white or blue with interesting lettuce-green foliage. | 7-10 |
| |
| SYMPHYTUM (Comfrey) |
| |
| | Ornamental coloured foliage with blue and white flowers. Good ground cover. | 4-5 |
| |
| TANACETUM |
| |
| | Mat forming, with pinnate, silver-grey leaves. White daisy flowers. | 6-8 |
| |
| TELLIMA |
| |
| | Rosettes of heart-shaped, scolloped, purple leaves with spikes of pink fringed, green flowers. | 5-6 |
| |
| THALICTRUM (Meadow Rue) |
| |
| | Fern-like foliage with heads of fluffy, purple, pink or white flowers. | 6-8 |
| |
| TIARELLA (Foam Flower) |
| |
| | Lobed, maroon-tinted, hairy, ovate leaves. Fragrant, white flower spikes. | 5-6 |
| |
| TRADESCANTIA (Spiderwort) |
| |
| | Iris-like foliage with white, blue, pink or purple flowers. | 6-9 |
| |
| TRICYRTIS (Toad Lily) |
| |
| | Glossy, dark green leaves. Star-shaped, white, purple-spotted flowers. | 6-10 |
| |
| VERBASCUM (Mullein) |
| |
| | Rosettes of felted foliage and tall spikes of yellow, white, pink or mauve flowers. | 6-9 |
| |
| VERBENA |
| |
| | bonariensis-Tall, rigid stems, topped with clusters of scented, mauve flowers. | 7-10 |
| |
| VERONICA (Speedwell) |
| |
| | Spikes of blue, white, or red flowers. | 5-7 |
| |
| VERONICASTUM (Culvers Physic) |
| |
| | Spires of small blue-purple flowers. | 6-9 |