Horticulture John W. Jett, Horticulture Specialist WVU Extension Service May 2005 Plant pH Preferences Due to variations in soil and climate authors do not always agree about the pH preferences of crops, but the following is a range that should be acceptable. Ornamentals and Houseplants pH 4.5 Anemone Iris kaempferi Autumn Gentains Mecanopsis Gentian pH 4-5 – 5.5 Aspidistra Orchid (most) Azalea Pachysandra terminalis Camelia Parlour palm (Aspidistra) Columnea pH 5.5 Auricaria Pitcher plant (Nepenthes) Cactus (most) Primrose (Primula) Crassula Urn plant (Aechemea) Norfolk Island pine (Auricaria) pH 5.5 – 6.0 Amaryllis Anthurium Bilbergia Butterfly flower (Schizanthus) Calliopsis (Coreopsis) Christmas cactus (Zygocactus) Cissus Clary (Salvia) Clerodendron Creeping fig (Ficus pumilla) Croton Dracaena Dumb cane (Diffenbachia) Flamingo flower (Anthurium) Gardenia Iresine Kangaroo vine (Cissus) Maranta Monsteria Pandanus Pepperomia Philodendron Phlox Pick a back (Ptolmeia) Prayer plant (Maranta) Rubber plant (Ficus) Silk oak (Grevillia) Swiss cheese plant (Monsteria) Tradescantia Zebrina pH 5.5 – 6.75 Begonia Clarkia Chrysanthemum Cineraria Flame nettle (Coleus) Fuchsia Gloxinia (Sinningia) Grasses (Agrostis sp) Lupin Marigold (Tagetes) Mother in law tongue (Sanseveria) Pansy (Viola) Poinsettia (Euphorbia) Sanseveria Slipperwort (Calceolaria) Violet (Viola) pH 5.5 – 7.5 Cosmos (Cosmea) Indian shot (Canna) Nasturium (Tropaeolium) pH 6.0 Campanula Clivia Crassula Fittonia Grevillia Gynura Hoya (wax flower) Michelmas daisy (Aster) Neomarcia Plumbago Poor man’s orchid (Schizanthus) Primula Purslane (Portulaca) Rose (Rosa) Shrimp plant (Dredgerella) Snakeskin plant (Fittonia) Swainsonia Tuberose Waterlily (Nymphea) pH 6.0 – 6.5 Alyssum Programs and activities offered by the West Virginia University Extension Service are available to all persons without regard to race, color, sex, disability, relig- ion, age, veteran status, political beliefs, sexual orientation, national origin, and marital or family status. Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Director, Cooperative Extension Service, West Virginia University. West Virginia University is governed by the Board of Trustees of the University System of West Virginia. pH 6.0 – 6.75 African violet (St Paulia) Baby’s breath (Gypsophia) Bird of paradise (Strelitzia) Bougainvillea Burning bush (Kochia) Busy lizzie (Impatiens) Calendula Candytuft (Iberis) Carnation (Dianthus) Coleus Columbine (Aquilegia) Coral bells (Heuchera) Cyclamen Daffodil (Narcissus) Dahlia Delphinium Easter lily (Zantedeschia) Gladiolus Hollyhock (Althea) Narcissus Primrose (Primula) Red hot poker (Kniphophia) Salvia Scabious Snapdragon (Antirrhinum) Spring gentian (Gentiana verna) Stock (Mathiola) Sunflower (Helianthus) Tobacco (Nicotiana) Tulip Viola Wallflower Zinnia pH 6.0 – 7.5 Ageratum Avens (Geum) Feverfew (Chrysanth) Impatiens Iris Ladys slipper orchid (Cypripedium & Paphiopedulum) Lillies (Lilium) Lobelia Petunia Verbena pH 6.75 Aster Bachelor’s buttons (Ranunculus) Bearded Iris Bleeding heart (Dicentra) Cockscombe (Celosia) Coconut palm (Cocos) Daisy (Bellus) Euphorbia Foxglove (Digitalis) Freesia Gerbra Godetia Larkspur (Delphinium) Marigold (Calendula) Oleander (Nerium) Orange (Citrus) Polemonium (Jacobs Ladder) Portulaca Pyrethrum Spurge (Euphorbia) pH 6.75 - 7.5 Annual Phlox Asparagus fern Bluebell (Scilla) Cherry pie (Heliotrope) Crocus Day lily (Hemerocalis) Fern, maidenhair (Adiantum) Flax (Linum) Forget me not (Myosotis) Geranium (Pelargonium) Hyacinth Iceland poppy (Papaver) Lily madonna (Lilium candidum) Love lies bleeding Morning glory (Ipomea) Oxalis Pelargonium Pepper (Capsicum) Peony Pink (Dianthus) Poppy (Papaver) Snowdrop (Galanthus) Star of Bethlehem (Campanula) Sweet pea (Lathyrus) Sweet William (Dianthus) Ornamentals and Houseplants - continued Trees and Shrubs pH 4.5 Bilberry (Vaccinium) Chillean pernettya (Pernettya) Flame of the forest (Pieris) Hydrangea (Blue) Ledum London season (Zenobia) Phyllodoce Pin oak (Quercus palustris) – tree Sweet gum (Liquidamber) - tree pH 4-5 – 5.25 Azalea Camelia Rhododendron pH 4-5 – 6.0 Heather (Erica) Magnolia - tree pH 5.25 Conifers (most) - tree Pine (Pinus) - tree pH 5.25 – 6.0 American Laurel (Kalmia) Arucaria - tree Birch (Betula) – tree Boronia Californian lilac (Ceanothus) Cinquefoil (Potentilla) Dogwood (Cornus) Hemlock (Tsuga) - tree Leucothoe Leptospermium (Tea tree) Photina Rosemary (Rosmarinus) Snowbells (Stryax) Strawberry tree (Arbutus) – tree Sweet fern (Comptonia) Wintergreen (Gaultheria) pH 5.25 – 6.75 Holly (Ilex) - tree pH 5.25 – 7.5 Crab (Malus) - tree pH 6.0 Balsam fir (Abies) - tree Juniper (Juniperus) - tree Monkey puzzle (Auricaria) – tree pH 6.0 – 6.75 Almond (Prunus) – tree Antler tree (Rhus) - tree Apple (Malus) - tree Ash (Fraxinus) - tree Fuchsia Hawthorn (Cretagus) - tree Hydrangea (Pink) Lavender (Lavendula) Passion flower (Passiflora) Pear (Pyrus) - tree Plum (Prunus) – tree Privet (Ligustrum) Quince (Chaenomeles) Rose (Rosa) Yew (Taxus) pH 6.0 – 7.5 Clematis Currant, flowering (Ribes) Daphne Eucalyptus - tree Forsythia Grape vine (Vitis) Jasmine (Jasminum) Laurel (Prunus laurocerasus) Lilac (Syringa) - tree Mezeron (Daphne) Mulberry (Morus) - tree Poplar (poplus) – tree Rock rose (Cistus) Senecio Stags horn (Rhus) - tree Veronica (Hebe) Vine (Vitis) Willow (Salix) - tree Witch hazel (Hamamelis mollis) pH 6.75 Box (Buxus) Douglas fir (Pseudotsuga) - tree Genista Hibiscus Rose of Sharon (Hypericum) pH 6.75 - 7.5 Abele (Poplus alba) – tree Acacia - tree Adam’s needle (Yucca) Arbor vitae (Thuja) – tree Barberry (Berberis) Blackcurrant (Ribes) Boston Ivy (Parthenocissus) Bridal wreath (Spirea arguta) Butterfly bush (Buddleia) Cherry (Prunus) – tree Cotoneaster Deutzia Diervilla (Wygelia) Escallonia Euonymus Firethorn (Pyracantha) Golden bells (Forsythia) Golden Rain (Laburnum) – tree Guelder rose (Viburnum) Honeysuckle (Lonicera) Hydrangea (white) Ivy (Hedera) Japonica (Caesalpina) Jews mallow (Kerria) Maple (Acer) – tree Mock orange (Philadelphus) Myrtle (Myrtus) Peach (Pumus persica) Rose mallow (Hibiscus) Spanish gorse (Genista) Spirea St. John’s wort (Hypericum) White poplar (Poplus alba) – tree Wisteria pH 4-5 – 5.25 Bilberry Cranberry pH 5.25 – 6.0 Blackberry Chicory Gooseberry Pineapple Potato Rosemary Sage Strawberry pH 5.25 – 6.75 Apples Rhubarb pH 6.0 Aubergine Eggplant Rye pH 6.0 – 6.75 Almond Bean, broad Bean, climbing Bean, runner Brussels sprouts Carrots Climbing bean Courgette Endive Kale Lemon Lentil Marrow Olives Parsley Pear Pumpkin Raspberry Shallots Soyabean Squash Swede Thyme Watermelon pH 6.0 – 7.5 Bean, French Broccoli Cabbage Capsicum Cauliflower Celery Cherries Chives Corn Cucumber Currants Garlic Horseradish Lettuce Mulberry Mustard Onions Parsnip Peach Peas Peppers Plum Radish Sweet corn Tomato Turnips pH 6.75 Bean, lima Cantaloupe, melon Kohl rabi Orange Quince Salsify Scorzonera Swiss chard pH 6.75 - 7.5 Alfalfa Artichoke, Jerusalem Asparagus Avacado Barley Beet, sugar Beetroot Grape vine Leek Mushroom Pecan Spinach Watercress Vegetables, Fruit, Herbs, and Food Plants