old-fashioned bleeding
heart, 386
Olympic mullein, 336
Olympic Scotch bluebell, 180
Onagraceae, 217, 275
Onoclea sensibilis, 212, 343,
350
orange coneflower, 301
ordering plants, 381, 388,
389, 39 1
oregano, ornamental
‘Herrenhausen’, 277
‘Kent Beauty’, 276
organic fertilizers, 55, 73
organic matter
adding for good drainage,
33
adding when planting and
transplanting, 49–50
amounts to add, 32, 33, 40,
42–43
building up in soil, 54
choosing types to use,
35–36
in compost, 29, 35–36, 39
effect on plant growth, 15,
34, 41
incorporating in initial
bed preparation, 29, 30,
35, 40, 52, 55
physical, chemical, and
biological benefits of,
34–35
from plants, 54
standards for content, 32,
36
See also soil amendments
oriental fountain grass, 229
oriental poppy, 79, 110, 279,
280
Origanum, 344, 347, 350, 373,
374
‘Kent Beauty’, 276 , 363,
364
Origanum laevigatum
‘Herrenhausen’, 277
Origanum rotundifolium ×
Origanum scabrum, 276
Origanum vulgare, 277
‘Aureum’, 277
ornamental grasses.
See grasses / ornamental
grasses
ornamental oregano
‘Herrenhausen’, 277
‘Kent Beauty’, 276
ornamental rhubarb, 300
Osmunda, 343, 350
Osmunda cinnamomea, 212
Osmunda claytoniana, 212
Osmunda regalis, 212
Osmundastrum
cinnamomeum, 211, 212
ostrich fern, 210, 212
overhangs in site selection,
14–15
overwintering, 131–133Pacific Giant hybrid
delphiniums, 23, 25, 7 6
Paeonia, 79, 350
‘Nymphe’, 278
Paeoniaceae, 278
Paeonia hybrids, 278
maintenance needs lists,
34 9, 351, 355, 357, 358,
359, 366, 376, 377
Paeonia tenuifolia, 279
‘Flore Plena’, 66
painted arum, 130, 166
‘Painter’s Palette’ knotweed,
283
‘Palace Purple’ coralbells, 240
pale purple coneflower, 205
Panicum, 130
Panicum virgatum, 229, 343,
345, 347, 361, 362
‘Cheyenne Sky’, 229
‘Dallas Blues’, 229
‘Northwind’, 229
‘Rehbraun’, 229
‘Shenandoah’, 229
Papaver, 50
Papaveraceae, 200, 269, 279,
29 7, 321
Papaver nudicaule, 280
Papaver orientale, 279 , 350,
354, 357, 364, 366, 369,
37 0, 373, 376, 377
cutting to the ground, 110
deadheading as
unnecessary, 104
‘Patty’s Plum’, 350
parsley family, 65
Parthenium integrifolium, 345
pasque flower, 157
paths, 58, 59
patrinia, 280
Patrinia scabiosifolia, 280 ,
354, 356, 361, 362, 367,
373, 374, 376
peachleaf bellflower, 98, 179
pearly everlasting, 64
pea staking, 76, 382, 384
Pectobacterium carotovorum,
69
Pennisetum, 229
‘Karley Rose’, 229‘Tall Tails’, 229
Pennisetum alopecuroides
‘Hameln’, 227, 229, 347
‘Moudry’, 229, 361, 362
Pennisetum orientale, 229, 361
Penstemon, 350
‘Prairie’ series, 281
‘Prairie Twilight’, 281
‘Red Riding Hood’, 281
‘Riding Hood’ series, 281
Penstemon barbatus, 280 ,
344, 348, 356, 358, 367,
369, 373, 374, 376
Penstemon digitalis, 131, 281
‘Dark Towers’, 281
‘Husker’s Red’, 116, 281
Penstemon ×mexicali, 281
‘Pike’s Peak Purple’, 281
‘Red Rocks’, 281
peonies, 25, 55, 66, 79, 126,
132, 278, 384, 388, 389
Bridal Series, 27 9
‘Festiva Maxima’, 67
‘Mister Ed’, 279
‘Nice Gal’, 67, 279
‘Nymphe’, 279
‘Snow Swan’, 279
‘Vivid Rose’, 279
percolation test, 33
perennial flax, 261
Perennial Plant Association
(PPA) soil standards, 32
Perovskia atriplicifolia, 282 ,
344, 347, 350, 355, 364,
368, 369, 373, 37 4
dividing, 79
‘Longin’, 282
pinching, 122
perovskia / Perovskia, 134,
282
Persicaria, 147, 283, 377
Persicaria affinis, 283
‘Superba’ a.k.a ‘Dimity’,
283
Persicaria amplexicaulis
‘Firetail’, 283 , 349, 356,
359, 371, 373
‘Golden Arrow’, 283
Persicaria microcephala ‘Red
Dragon’, 284, 368
Persicaria polymorpha, 147
Persicaria virginiana
‘Painter’s Palette’, 283, 361,
362
pests and pest control,
63–66, 68–73
“petal droppers”, 104
pH, 32