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Plant guides · A to Z

Plants starting with O.

25 guides

  • Oak Quercus

    Oaks are iconic, long lived trees that serve as cornerstones for many ecosystems. They come in a wide variety of...

  • Oat Avena sativa

    Oats are a classic cereal grain that you can easily grow in your garden for both beauty and harvest. They thrive in...

  • Obedient plant Physostegia virginiana

    The obedient plant is a charming perennial that gets its name from the way its flowers stay in place when you push...

  • oceanspray Holodiscus discolor

    Oceanspray is a lovely native shrub that puts on a show with its cascading clusters of creamy white flowers. It's a...

  • Ocotillo Fouquieria splendens

    The Ocotillo is a striking desert shrub that looks like a bundle of thorny sticks for most of the year. It quickly...

  • Okra Abelmoschus esculentus

    Okra is a warm season vegetable that thrives in sunny garden spots. It produces beautiful hibiscus like flowers...

  • Old man cactus Cephalocereus senilis

    The old man cactus is a striking succulent known for its long, shaggy white hairs that cover its columnar body. It...

  • Oleander Nerium oleander

    Oleander is a stunning evergreen shrub known for its beautiful, long blooming flowers. It thrives in warm climates...

  • Olive tree Olea europaea

    The olive tree is a beautiful, slow growing evergreen with silvery green foliage that brings a Mediterranean feel to...

  • Onion Allium cepa

    The onion is a popular biennial vegetable grown for its edible, pungent bulb. It is a staple in gardens worldwide...

  • Opium poppy Papaver somniferum

    The opium poppy is a stunning annual known for its papery, delicate petals and attractive seed pods. It thrives in...

  • Opposite-leaved golden-saxifrage Chrysosplenium oppositifolium

    This charming little plant loves damp, shaded spots near streams or in wet woodlands. It forms low mats of bright...

  • Orach Atriplex hortensis

    Orach is a lovely, fast growing leafy green that brings a splash of color to the garden. It is a hardy annual that...

  • Orange Daylily Hemerocallis fulva

    The orange daylily is a hardy perennial known for its trumpet shaped blooms that open for just one day. It is a...

  • Orange hawkweed Pilosella aurantiaca

    This charming perennial is known for its vibrant, fiery orange blooms that really stand out in a garden. It spreads...

  • Orange Jessamine Murraya paniculata

    Orange Jessamine is a lovely evergreen shrub known for its glossy, dark green leaves and highly fragrant white...

  • Orange jewelweed Impatiens capensis

    This charming native plant is famous for its bright orange, spotted flowers that dangle like little jewels. It loves...

  • Orchard grass Dactylis glomerata

    Orchard grass is a hardy, cool season perennial bunchgrass often found in pastures and meadows. It is well known for...

  • Oregano Origanum vulgare

    Oregano is a hardy, aromatic herb that brings a wonderful Mediterranean flavor to your kitchen. It thrives in sunny...

  • Oregon Grape Mahonia aquifolium

    Oregon Grape is a lovely evergreen shrub native to the Pacific Northwest. It features glossy, holly-like leaves and...

  • Oriental bittersweet Celastrus orbiculatus

    Oriental bittersweet is a vigorous, deciduous woody vine known for its aggressive climbing habit. It produces small,...

  • Ornamental Onion Allium

    Alliums are charming bulbs that bring unique, globe shaped blooms to your garden. They're part of the onion family...

  • Ornamental Pineapple Ananas comosus var. bracteatus 'Variegatus'

    The ornamental pineapple is a striking tropical plant known for its vibrant, spiky foliage and small, decorative...

  • Osage orange Maclura pomifera

    The Osage orange is a tough, deciduous tree known for its unique, bumpy, grapefruit sized fruits. It was...

  • Ox-eye Daisy Leucanthemum vulgare

    The ox-eye daisy is a cheerful wildflower that brings a classic meadow look to any garden. It is a hardy perennial...