Saving and Starting Perennials Seeds

For the More Advanced Gardener, Perennials 101

For hybrid selections of things like Daylilies (Hemerocallis) or Hosta, just be aware that the resulting seedlings are not likely to resemble the parent plant.  Seed saved from a ‘Stella de Oro’ Daylily, for instance, will probably not produce the same constant-flowering, dwarf plant with golden-yellow flowers.  Instead, a range of shades will result and most will not inherit the repeat flowering gene, which is a recessive trait.  Plants that result might well be garden-worthy and attractive, so if you’re curious to see what might happen, go ahead and try it!

In late summer and fall, many kinds of perennials begin to form seed heads, and gardeners often ask us how to go about collecting seed to start their own plants.

 

Seed pods should begin to change from green to a tan or brownish colour, and develop a brittle or papery texture when the seeds inside are ripe.  Gathering too soon may result in non-viable seed.  If you wait too long, certain kinds of seeds will drop from the heads or pods, be blown away in the wind or gobbled by birds, so watch the heads carefully for just the right moment to harvest.

Place collected seedheads into brown paper bags and store in a dry, ventilated location for a few weeks to ripen further and continue drying.  Don’t forget to write the name of the plant on the seed bag!

Once the heads are dried, seeds can be cleaned from the chaff by dumping into a pie plate and using your fingers to break apart the pods or heads. Kitchen sieves of various sizes are sometimes handy to sift the actual seed from the other dried bits of plant material. Gently blowing the lighter chaff from the seed is an ancient and effective way to clean small batches.

If your only seed starting experience has been with easily germinated vegetables or annual flowers, more patience is going to be required when it comes to growing perennials from seed successfully. Some types germinate within days, others take several weeks, and a large number of perennials require what is called stratification — basically, simulating the conditions that exist outside over the winter. These types of seed are sometimes described as “cold germinators”.

The usual trick is to place the seed with some moist, sterilized commercial seeding mix inside a plastic bag, then storing it in a refrigerator for a period of time to break down the natural chemical germination inhibitors within the seed. A typical period of time is about three to four months. Then the seed is sowed as usual and started indoors under lights. Another approach is to sow the seed in late fall in pots, then leave it outside in a protected (but unheated) coldframe for the winter.

Here are few helpful links to get you started:

  • Starting Perennial Seeds by Canadian author Douglas Green. Great information, with easy-to-understand but thorough details.
  • For the Advanced seed starter, Tom Clothier’s terrific Perennial Seed Germination Database has an extensive listing of perennials along with the specific germination requirements to get your seeds off to a good start. It even includes many of the trickier native woodland plants that need stratification and other seed treatments. If you’ve ever sowed perennial seeds and nothing happened, here is the place to find your answers.

EASY GERMINATORS: These seeds are great ones to get started with, especially if you plan to sow seeds indoors under lights. None require any special cold treatment. Just sow as for tomatoes or peppers but allow 6 to 12 weeks for germination:

Achillea (Yarrow), Alcea (Hollyhock), Alyssum (Perennial Alyssum), Anthemis (Perennial Marguerite), Aquilegia (Columbine), Arabis (Wall Cress), Armeria (Thrift), Aster, Aubrieta (Rock Cress), Aurinia (Basket-of-Gold), Bellis (English Daisy), Campanula carpatica, Campanula persicifolia (Bellflower), Catananche (Cupid’s Dart), Centaurea (Cornflower), Centranthus (Red Valerian), Cerastium (Snow-in-Summer), Coreopsis (Tickseed), Cynara (Cardoon, Globe Artichoke), Dianthus (Pinks, Carnations, Sweet William), Digitalis (Foxglove), Doronicum (Leopard’s Bane), Echinacea purpurea (Purple Coneflower), Echinops (Globe Thistle), Erigeron (Fleabane Daisy), Erysimum allionii (Siberian Wallflower), Gaillardia (Blanket Flower), Geum (Avens), Gypsophila (Baby’s-Breath), Helenium (Helen’s Flower), Hesperis (Dame’s Rocket), Heuchera (Old-fashioned Coral Bells), Kniphofia (Torchlily), Leucanthemum (Shasta Daisy), Liatris (Blazingstar), Limonium (Sea Lavender), Linum perenne (Blue Flax), Lunaria (Money Plant, Silver Dollar), Lupinus (Lupine, best sown directly outside in late spring), Lychnis (Campion), Malva (Mallow), Monarda (Beebalm), Myosotis sylvatica (Forget-me-not), Origanum (Oregano), Papaver (Poppy), Physostegia (Obedient Plant), Polemonium (Jacob’s Ladder), Potentilla (Cinquefoil), Rudbeckia hirta (Gloriosa Daisy), Salvia (Perennial Sage), Stachys (Lamb’s Ears), Tanacetum (Painted Daisy, Feverfew), Thymus serpyllum (Mother-of-Thyme), Verbascum (Mullein), Verbena, Veronica most tall types (Speedwell), Viola hybrids (Winter Pansy).

FOR ADVANCED SEED STARTERS ONLY: These seeds are trickier to handle. Many are tiny, and most require a special cold treatment or absolutely nothing will happen. See the germination link above for specific details:

Acanthus (Bear’s-Breeches), Aconitum (Monkshood), Alchemilla (Lady’s Mantle), Alstroemeria (Peruvian Lily), Anemone (Windflower), Angelica, Arum, Aruncus (Goat’s Beard), Asarum (Wild Ginger), Asclepias (Milkweed), Astrantia (Masterwort), Baptisia (False Indigo), Bergenia, Buddleia (Butterfly Bush), Caltha (Marsh Marigold), Caryopteris (Bluebeard), Chelone (Turtlehead), Chrysogonum (Golden Star), Cimicifuga (Bugbane), Clematis, Corydalis (Fumitory), Crambe (Seakale), Cyclamen, Delphinium, Dicentra (Bleedingheart), Dictamnus (Gas Plant), Dodecatheon (Shooting Star), Eremurus (Foxtail Lily), Eryngium (Sea Holly), Eupatorium (Boneset), Euphorbia (Spurge), Filipendula (Meadowsweet), Fuchsia, Gaura (Butterfly Gaura), Gentiana (Gentian), Geranium species (Cranesbill Geranium), Goniolimon (German Statice), Gunnera, Helianthemum (Rock Rose), Helianthus (Perennial Sunflower), Heliopsis (False Sunflower), Helleborus (Christmas & Lenten Rose), Heuchera hybrids (Fancy-leaf Coral Bells), Hibiscus (Hardy Hibiscus), Hypericum (St. John’s-Wort), Iberis (Perennial Candytuft), Incarvillea (Hardy Gloxinia), Iris species, Jasione (Shepherd’s Bit), Kirengeshoma (Waxbells), Knautia (Crimson Scabious), Lathyrus (Perennial Sweet Pea), Lavandula (Lavender), Lavatera (Tree Mallow), Leontopodium (Edelweiss), Lewisia, Ligularia, Lobelia, Lysimachia (Loosestrife), Macleaya (Plume Poppy), Mazus (Creeping Mazus), Mertensia (Virginia Bluebells), Myrrhis odorata (Sweet Cicely), Nepeta (Catmint), Oenothera (Evening Primrose, Sundrops), Omphalodes (Naval-seed), Penstemon (Beard-tongue), Perovskia (Russian Sage), Persicaria (Fleeceflower), Phlomis, Phlox (all types), Physalis (Chinese Lantern), Platycodon (Balloon Flower), Podophyllum (May Apple), Primula (Primrose, all types), Pulsatilla (Pasque-flower), Ranunculus (Buttercup), Ratibida (Prairie Coneflower), Rheum (Rhubarb), Rodgersia, Rosmarinus (Rosemary), Rudbeckia (Black-eyed Susan, most types), Rumex sanguineus (Bloody Dock), Sanguinaria (Bloodroot), Sanguisorba (Burnet), Saponaria (Soapwort), Saxifraga (Saxifrage), Scabiosa (Pincushion Flower), Sedum (Stonecrop), Sempervivum (Hen-and-Chicks), Sidalcea (Prairie Mallow), Silene (Campion, Catchfly), Sisyrinchium (Blue-eyed Grass), Stokesia (Stokes’ Aster), Teucrium (Germander), Thalictrum (Meadow-rue), Tiarella (Foamflower), Tradescantia (Spiderwort), Tricyrtis (Toad-lily), Trollius (Globeflower), Vernonia (Ironweed), Veronica Dwarf Types (Speedwell), Veronicastrum (Culver’s-root), Viola species types (Violets), Waldsteinia (Barren Strawberry), Zantedeschia (Calla Lily).

NOT WORTH THE BOTHER: The types listed below either will not come true from seed or are so slow it’s not usually worth the wait. Peonies, for instance, can take five years or more to reach flowering size from seed. Instead, start with containers of perennials from your local Heritage Perennials Dealer, or trade for good-sized divisions with gardening friends:

Artemisia, Astilbe, Brunnera (Siberian Bugloss), Convallaria (Lily-of-the-Valley), Crocosmia (Montbretia), Darmera (Umbrella Plant), Epimedium (Barrenwort), Galium (Sweet Woodruff), Geranium Named Selections (Cranesbill Geranium), Hemerocallis Named Selections (Daylily), Hosta Named Selections (Plantain Lily), Houttuynia cordata (Chameleon Plant), Humulus lupulus ‘Aureus’ (Golden Hops), Iris Named Hybrids of Bearded, Siberian, Japanese Iris, Kalimeris (Japanese Aster), Lamiastrum (False Lamium), Lamium maculatum (Creeping Lamium), Lilium species and hybrids (Lily), Liriope (Lily-turf), Lithodora (Lithospermum), Meconopsis (Himalayan Blue Poppy), Ophiopogon (Mondo Grass), Pachysandra (Japanese Spurge), Paeonia (Peony, all kinds), Polygonatum (Solomon’s Seal), Pulmonaria (Lungwort), Sagina (Irish and Scotch Moss), Solidago Named Selections (Goldenrod), Symphytum (Comfrey), Thymus Named Selections (Thyme), Vinca minor (Periwinkle).