The guide below compliments our flower seed sowing guide, with additional information on height, sun exposure, bloom time and toxicity to cats, dogs and people.
| Height | Sun exposure | Flowers | Toxic? | |
| African daisy (Arctotis stoechadifolia) | 30 cm | Full sun | Late spring/early summer | Non-toxic |
| African daisy (Osteospermum spp.) | 30 – 90 cm | Full sun | Early summer | Non-toxic |
| Alyssum (Lobularia maritima) | 7 cm | Full sun/partial shade | Spring to autumn | Non-toxic |
| Amethist flower (Browallia spp.) | 30 – 90 cm | Full sun/partial shade | Summer/autumn | Toxic |
| Aster (Aster spp.) | 30 – 120 cm | Full sun | Late summer/mid autumn | Non-toxic |
| Baby’s breath (Gypsophila spp.) | 15 – 90 cm | Full sun | Summer/autumn | Non-toxic |
| Balloon flower (Platycodon grandiflorus) | 30 – 90 cm | Full sun/part shade | Late spring/summer | Toxic |
| Bear’s breeches (Acanthus mollis) | 90 – 120 cm | Full sun/part shade | Late spring/summer | Unknown |
| Bee balm (Monarda didyma) | 90 – 120 cm | Full sun/dappled shade | Late spring/early summer | Non-toxic |
| Begonia (Begonia spp.) | 15 – 60 cm | Part shade | Mid summer/autumn | Toxic |
| Bellflower (Campanula spp.) | 120 cm | Full sun | Spring/mid-summer | Non-toxic |
| Bells-of-Ireland (Moluccella laevis) |
100 cm | Full sun | Summer | Non-toxic |
| Black-eyed Susan (Rudbeckia hirta) | 60 – 90 cm | Full sun/part shade | Late summer/autumn | Toxic |
| Bleeding heart (Dicentra spectabilis) | 75 – 90 cm | Part/full shade | Late spring/summer | Toxic |
| Blanket flower (Gaillardia x grandiflora) |
40 cm | Full sun | Early summer/autumn | Non-toxic |
| Boltonia (Boltonia spp.) | 150 – 180 cm | Full sun | Late summer/early autumn | Unknown |
| Borage (Borago officinalis) | 50 – 90 cm | Full sum/part shade | Early summer/early autumn | Cats and dogs, not humans |
| Bugloss (Anchusa capensis) | 60 cm | Full sun/part shade | Summer | No |
| Butter daisy (Melampodium paludosum) |
20 – 40 cm | Full sun | Summer | Unknown |
| Butterfly flower (Schizanthus spp.) | 30 – 50 cm | Full sun | Spring to autumn | Non-toxic |
| Butterfly pea (Clitoria ternatea) |
3 metres | Full sun | Mid to late summer | Non-toxic |
| Butterfly weed (Asclepias tuberosa) | 30 – 60 cm | Full sun | Late spring and summer | Toxic |
| Calendula (Calendula officinalis) | 80 cm | Full sun | Spring and summer | Non-toxic |
| Californian poppy (Eschscholzia californica) | 20 cm | Full sun | Late spring to summer | Non-toxic |
| Candytuft (Iberis spp.) | 30 cm | Full sun | Spring and summer | Toxic |
| Canterbury bells (Campanula medium) | 60 – 90 cm | Full sun/part shade | Summer | Non-toxic |
| Cape jewels (Nemesia strumosa) | 30 cm | Full sun/part shade | Late spring to autumn | Non-toxic |
| Carnation (Dianthus spp.) | 30 – 50 cm | Full sun | Late spring to summer | Toxic |
| Catnip/catmint (Nepeta spp.) | 30 – 50 cm | Full sun | Late spring to autumn | Non-toxic |
| Chamomile (Matricaria chamomilla) | 50 – 80 cm | Full sun | Mid to late summer | Toxic to cats and dogs, not humans |
| Chilean bellflower (Lapageria rosea) |
1 metre | Full sun/part shade | Late summer and autumn | Unknown |
| Chinese aster (Callistephus chinensis) | 30 – 90 cm | Full sun/part shade | Late summer and autumn | Non-toxic |
| Chinese forget-me-not (Cynoglossum amabile) |
40 cm | Full sun/part shade | Summer | Toxic |
| Chinese lantern (Physalis alkekengi) | 40 – 60 cm | Full sun/part shade | Summer | Toxic |
| Chrysanthemum (Chrysanthemum spp.) | 40 – 100 cm | Full sun | Summer to autumn | Toxic |
| Clematis (Clematis spp.) | 2.4 – 3.6 metres | Full sun | Spring | Toxic |
| Cliquefoil (Potentilla spp.) | 30 – 90 cm | Full sun/part shade | Late spring to autumn | Non-toxic |
| Cohosh (Cimicifuga spp.) | 25 – 60 cm | Part to full shade | Late summer to early autumn | Unknown |
| Columbine (Aquilegia spp.) | 30 – 45 cm | Full sun | Spring | Yes |
| Common rockrose (Helianthemum nummularium) | 15 – 30 cm | Full sun | Spring and summer | Unknown |
| Common sneezeweed (Helenium autumnale) | 90 cm | Full sun | Autumn | Toxic |
| Coral bell (Heuchera spp.) | 20 – 30 cm | Full sun/part shade | Spring to autumn | Non-toxic |
| Corncockle (Agrostemma githago) | 30 – 60 cm | Full sun | Summer | Toxic |
| Cornflower (Centaurea cyanus) | 90 cm | Full sun | Spring to summer | Non-toxic |
| Cosmos (Cosmos bipinnatus) | 90 cm to 1.5 metres | Full sun | Summer | Non-toxic |
| Cup and saucer vine (Cobaea scandens) | 1.5 to 3 metres | Full sun | Late summer | Non-toxic |
| Cupflower (Nierembergia spp.) | 5 cm | Full sun/part shade | Mid-summer to mid-autumn | Toxic |
| Cupid’s bow (Achimenes spp.) | 30 cm | Bright/indirect sun | Summer to autumn | Non-toxic |
| Cupid’s dart (Catananche caerulea) | 18 – 28 cm | Full sun | Mid-summer to autumn | Non-toxic |
| Cyclamen (Cyclamen spp.) | 20 cm | Part shade | Late winter to spring | Toxic |
| Dahlberg daisy (Thymophylla tenuiloba) |
15 – 30 cm | Full sun | Summer to early autumn | Toxic |
| Dahlia (Dahlia spp.) | 15 cm to 1.2 metres | Full sun | Late summer to autumn | Mildly toxic to cats and dogs, not humans |
| Delphinium (Delphinium elatum) | 100 – 150 cm | Full sun | Spring and summer | Toxic |
| Echinacea (Echinacea spp.) | 75 – 120 cm | Full sun/part shade | Summer and autumn | Non-toxic |
| Edeiweiss (Leontopodium alpinum) |
15 – 20 cm | Full sun | Late spring and summer | Unknown |
| English daisy (Bellis perennis) | 20 – 30 cm | Full sun/part shade | Spring and summer | Non-toxic |
| Evening primrose (Oenothera spp.) | 90 – 150 cm | Full sun | Late spring to early autumn | Toxic to cats and dogs, not humans |
| Everlasting (Helichrysum bracteatum) | 100 – 150 cm | Full sun | Spring and summer | Unknown |
| False sunflower (Heliopsis spp.) | 60 – 120 cm | Full sun | Summer | Non-toxic |
| Fan flower (Scaevola aemula) | 50 cm | Full sun/part shade | Summer to autumn | Non-toxic |
| Feverfew (Tanacetum parthenium) |
70 cm | Full sun/part shade | Summer to autumn | Unknown |
| Firecracker flower (Crossandra infundibuliformis) | 30 – 90 cm | Part shade | Spring to autumn | Non-toxic |
| Flax (Linum usitatissimum) | 30 – 100 cm | Full sun | Summer | Non-toxic |
| Fleabane (Erigeron spp.) | 20 – 30 cm | Full sun | Spring to autumn | Toxic |
| Floss flower (Ageratum houstonianum) | 30 – 100 cm | Full sun | Summer | Toxic |
| Forget-me-non toxict (Myosotis spp.) | 30 cm | Part shade | Spring | Non-toxic |
| Foxglove (Digitalis spp.) | 60 – 90 cm | Full sun/part shade | Spring and summer | Toxic |
| Garden heliotrope (Heliotropium spp.) | 10 – 50 cm | Full sun | Spring to late summer | Toxic |
| Gay feather (Liatris spp.) | 90 – 150 cm | Full sun/part shade | Mid to late summer | Non-toxic |
| Gazania (Gazania spp.) | 30 cm | Full sun/part shade | Spring to autumn | Non-toxic |
| Geranium (Pelargonium spp.) |
30 – 90 cm | Full sun/part shade | Spring to autumn | Toxic |
| Gerbera (Gerbera spp.) | 75 cm | Full sun | Late spring to autumn | Non-toxic |
| Geum (Geum spp.) | 30 – 90 cm | Part shade | Spring | Unknown |
| Globeflower (Trollius spp.) | 60 cm | Shade | Mid-spring to early summer | Non-toxic |
| Gloxinia (Sinningia speciosa) | 20 – 30 cm | Part shade | Late spring to autumn | Non-toxic |
| Goldencup (Hunnemannia fumariifolia) | 60 cm | Full sun | Mid-summer to early autumn | Unknown |
| Goldenrod (Solidago spp.) | 60 cm to 2.4 metres | Full sun | Mid to late summer | Non-toxic |
| Goldentuft (Aurinia saxatilis) | 5 – 10 cm | Full sun | Spring to early summer | Non-toxic |
| Hellebore (Helleborus spp.) | 30 cm | Part sun/dappled shade | Winter to spring | Toxic |
| Hibiscus (Hibiscus spp.) | 1 – 2 metres | Full sun | Mid to late summer | Non-toxic |
| Hollyhock (Alcea rosea) | 1.5 metres | Full sun | Summer | Non-toxic |
| Iceland poppy (Papaver nudicaule) | 30 – 45 cm | Full sun | Spring to early summer | Toxic |
| Impatiens (Impatiens spp.) | 1 metre | Full sun | Spring to autumn | Non-toxic |
| Jacob’s ladder (Polemonium spp.) | 45 – 60 cm | Full sun/part shade | Late spring to early summer | Non-toxic |
| Laceflower (Trachymene coerulea) | 80 cm | Full sun/part shade | Spring to summer | Unknown |
| Ladys purse (Calceolaria spp.) | 70 – 90 cm | Full sun/part shade | Early spring to summer | Non-toxic |
| Larkspur (Consolida ambigua) | 30 – 120 cm | Part sun/part shade | Summer | Toxic |
| Lavender (Lavandula spp.) | 30 – 90 cm | Full sun | Spring and summer | Toxic |
| Leopard plant (Ligularia spp.) | 30 cm | Part sun | Late summer | Non-toxic |
| Leopard’s bane (Doronicum cordatum) |
20 – 90 cm | Full sun/part shade | Summer to autumn | Toxic |
| Linaria (Linaria spp.) | 15 – 90 cm | Full sun | Late spring to late summer | Non-toxic |
| Lisianthus (Eustoma grandiflorum) | 15 – 60 cm | Full sun/part shade | Summer to autumn | Non-toxic |
| Livingstone daisy (Dorotheanthus bellidiformis) |
15 cm | Full sun | Spring | Non-toxic |
| Lobelia (Lobelia spp.) | 15 – 20 cm | Full sun/part shade | Spring to autumn | Toxic |
| Love-lies-bleeding (Amaranthus caudatus) | 90 – 120 cm | Full sun | Mid-summer to autumn | Non-toxic |
| Lupine (Lupinus spp.) | 90 cm | Full sun | Early summer | Toxic |
| Madagascar periwinkle (Catharanthus roseus) |
50 cm | Full sun/part shade | Late spring to autumn | Toxic |
| Maltese cross (Lychnis chalcedonica) |
30 – 50 cm | Full sun/part shade | Summer | Non-toxic |
| Marigold (Tagetes spp.) | 30 cm | Full sun/part shade | Summer to autumn | Toxic |
| Marshmallow plant (Althaea officinalis) | 90 cm to 1.2 metres | Full sun | Mid-summer | Non-toxic |
| Meadowsweet (Filipendula ulmaria) |
1 metre | Full sun/part shade | Late summer | Non-toxic |
| Mexican creeping zinnia (Sanvitalia procumbens) |
20 cm | Full sun | Summer to early autumn | Non-toxic |
| Mexican sunflower (Tithonia spp.) |
60 cm to 1.2 metres | Full sun | Summer | Non-toxic |
| Mignon toxicnette (Reseda odorata) | 30 cm | Full sun/part shade | Mid-summer to early autumn | Unknown |
| Monkey flowers (Mimulus spp.) | 15 cm | Full sun/part shade | Summer | Non-toxic |
| Monk’s hood (Aconitum spp.) | 1 metre | Full sun/part shade | Mid-summer | Toxic |
| Morning glory (Convolvulus spp.) |
2 metres | Full sun | Summer to autumn | Toxic |
| Mullein (Verbascum) | 30 cm to 1.2 metres | Full sun/part shade | Spring to summer | Toxic |
| Musk mallow (Malva moschata) |
60 cm | Full sun | Early summer to autumn | Non-toxic |
| Nasturtium (Tropaeolum majus) | 30 – 300 cm | Full sun | Spring to autumn | Non-toxic |
| Nemesia (Nemesia spp.) | 30 – 60 cm | Full sun | Spring and autumn | Non-toxic |
| Nemophila (Nemophila spp.) | 15 – 30 cm | Full sun/part shade (warm areas) | Mid-summer to late autumn | Unknown |
| Nigella (Nigella damascena) | 30 – 45 cm | Full sun/part shade | Spring | Mildly toxic |
| Obedient plant (Physostegia virginiana) | 90 – 120 cm | Full sun/part shade | Mid to late summer | Non-toxic |
| Pansy (Viola tricolor var. hortensis) | 20 cm | Full sun/part shade | Spring to summer | Mildly toxic |
| Pearly everlasting (Anaphalis margaritacea) | 30 – 90 cm | Full sun | Summer | Non-toxic |
| Persian violet (Exacum affine) | 20 – 30 cm | Morning sun | Spring to autumn | Non-toxic |
| Petunia (Petunia spp.) | 30 cm | Full sun | Summer | Non-toxic |
| Phlox (Phlox spp.) | 45 cm | Full sun | Summer to autumn | Non-toxic |
| Poppy (Papaver spp.) | 45 cm | Full sun | Spring | Toxic |
| Portulaca (Portulaca spp.) | 10 – 20 cm | Full sun | Summer | Toxic |
| Pride of Madeira (Echium candicans) | 1.5 – 2 metres | Full sun | Spring | Toxic |
| Primrose (Primula spp.) | 25 – 30 cm | Part shade | Spring | Toxic |
| Purple rock cress (Aubrieta deltoidea) | 10 – 20 cm | Full sun/part shade | Spring | Unknown |
| Queen Anne’s lace (Daucus carota) | 30 – 120 cm | Full sun | Mid-summer to mid-autumn | Toxic |
| Rock cress (Arabis spp.) | 10 – 20 cm | Full sun | Spring | Unknown |
| Salvia (Salvia officinalis) | 20 cm | Full sun | Mid-summer to mid-autumn | Non-toxic |
| Satin flower (Clarkia amoena) | 1 metre | Morning sun | Late spring to early summer | Unknown |
| Shooting star (Dodecatheon meadia) | 60 cm | Filtered shade | Mid spring | Non-toxic |
| Sea holly (Eryngium spp.) | 20 – 60 cm | Full sun | Summer to autumn | Toxic |
| Shasta daisy (Leucanthemum x superbum) | 60 – 90 cm | Full sun/part shade | Mid-summer to mid-autumn | Toxic |
| Snapdragon (Antirrhinum majus) | 60 cm | Full sun/part shade | Spring and autumn | Non-toxic |
| Snow-in-summer (Cerastium tomentosum) | 20 – 30 cm | Full sun/part shade | Late spring to early summer | Non-toxic |
| Speedwell (Veronica spp.) | 140 cm | Full sun/part shade | Spring to autumn | Toxic |
| Spider flower (Cleome hassleriana) |
150 cm | Full sun/part shade | Early summer to autumn | Non-toxic |
| Statice (Limonium sinuatum) | 50 cm | Full sun | Summer to autumn | Non-toxic |
| Stock (Matthiola incana) | 20 – 30 cm | Full sun to light shade | Late winter to spring | Non-toxic |
| Stoke’s aster (Stokesia laevis) | 150 cm | Full sun/part shade | Summer | Non-toxic |
| Sunflower (Helianthus spp.) | 30 cm – 1.8 metres | Full sun | Summer | Non-toxic |
| Swan river daisy (Brachyscome iberidifolia) | 30 cm | Full sun | Summer | Toxic |
| Sweet pea (Lathyrus odoratus) | 200 cm | Full sun | Summer | Toxic |
| Sweet rocket (Hesperis matronalis) |
80 cm | Full sun/part shade | Mid-spring to mid-summer | Non-toxic |
| Trumpet flower (Incarvillea spp.) | 30 – 40 cm | Full sun/part shade | Late spring to early summer | Non-toxic |
| Tweedia (Oxypetalum coeruleum) | 100 cm | Full sun | Spring and summer | Yes |
| Twinspur (Diascia spp.) | 25 – 40 cm | Full sun | Spring to autumn | No |
| Verbena (Verbena spp.) | 30 – 45 cm | Full sun | Early summer to autumn | Yes |
| Viola (Viola spp.) | 30 cm | Full sun (part shade in hot climates) |
Early summer to autumn | No |
| Virginian stock (Malcolmia maritima) | 15 – 30 cm | Full sun | Mid-summer to autumn | Unknown |
| Wallflower (Erysimum cheiri, syn. Cheiranthus cheiri) | 45 – 60 cm | Full sun | Spring to summer | No |
| Wild indigo (Baptisia spp.) | 90 – 120 cm | Full sun | Late spring to early summer | No |
| Wishbone flower (Torenia fournieri) | 15 – 30 cm | Part shade | Late spring to early summer | Unknown |
| Xeranthemum (Xeranthemum annuum) | 40 – 60 cm | Full sun | Summer to early autumn | Unknown |
| Yarrow (Achillea spp.) | 60 – 90 cm | Full sun | Summer to autumn | Yes |
| Zinnia (Zinnia spp.) | 120 cm | Full sun | Summer to autumn | No |
Julia is a writer and landscape consultant from Wollongong with a love of horticulture. She had been an avid gardener for over 30 years, collects rare variegated plants and is a home orchardist. Julia is passionate about learning and sharing her knowledge of plant propagation and plant toxicology. Whether it’s giving advice on landscape projects or sharing tips on growing, Julia enjoys helping people make their gardens flourish.
