Only January, Yet Already Time to Sow Seeds?

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It’s only January! Surely it’s too soon to sow seeds? Source: worldartsme.com, rdkate.blogspot.ca & mzayat. com

The new year has barely begun, yet now and over the coming month it’s already time to start certain seeds indoors.

This is a very select group of especially slow-to-mature plants. January is far too early for most seeds (think March or April instead), but you need about four to five months of indoor culture to bring the following plants to the right state of growth for outdoor planting.

  1. Agastache (Agastache foeniculum)
  2. Datura (Datura metel)
  3. Fairy Snapdragon (Chaenorrhinum origanifolium, syn. glaerosum)
  4. Lisianthus (Eustoma grandiflora)
  5. Spike dracaena or cabbage palm (Cordyline australis, syn. indivisa)
  6. Tritome (Kniphofia )
  7. Tuberous Begonia (Begonia × tuberhybrida)

No Easy Feat!

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Artificial light is almost essential for seeds started in January. Source: laidbackgardener. blog

Starting seed in January in the Northern Hemisphere is not simple. The days are short, the sun is weak and, in many areas, the weather is gray more often than sunny, meaning light is seriously lacking. Also, temperatures in front of the average windowsill are cool, yet almost all seeds need warmth—and fairly even temperatures—to germinate well. As a result, you pretty much have to start these under artificial lights, such as fluorescent or LED plant lights, and in the warmest part of your home.

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Germinate the seedlings under glass, possibly over a heating pad, as above. Source: www.amazon.fr

Always start winter-sown seeds “under glass” (under some sort of transparent covering) to maintain high humidity and stable temperatures and in a room that is at least moderately warm (72 to 75˚ F/21 to 24˚ C) or place the seed containers on a heating pad (one specifically designed for plants). Use a timer to set the day length of your lamp at 14 hours to simulate the long days of summer and place the containers of freshly sown seeds about 6 to 12 inches (15 to 30 cm) below the lamp. Now, wait patiently for germination to occur. (One reason that certain seeds need early sowing is that they are slow to germinate.)

Seeds That Require a Cold Treatment

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Many tree, shrub and perennial seeds need a cold treatment before they will germinate. Source: laidbackgardener. blog

January (or December or February) is also a good time to start seeds that need a cold treatment (cold stratification) to germinate well. This group includes most trees and shrubs from cold and temperate climates, but also many perennials and even a few annuals.

These seeds will not germinate until they have received a given number of days of cool, moist conditions, from as little as one or two weeks to four months or more, information you would (hopefully) find on the seed pack.

The number of weeks given is the minimum requirement for that species, but there is no maximum. So, if you keep seeds that need, say, a two-week treatment in the cold for two months, that’s not a problem. That’s nice to know, because the information on the minimum cold treatment for seed X is not always available, especially for seed you harvested yourself. If you don’t know, I suggest giving seeds of perennials a six to eight-week cold treatment: that’s usually enough. For trees and shrubs, I’d recommend three months.

Simply sow these seeds in a container as you would any other, then seal them inside a clear plastic bag and pop them into the refrigerator or cold room for at least the minimum number of weeks. Afterwards, move them to a warm, well-lit spot, on a windowsill or under lights, for germination to start.

100 Seeds That Need a Cold Treatment

Here are 100 plants that germinate best with a cold treatment (there are thousands of others!). Check the seed envelope or the seed supplier’s web site for more information.

  1. Abies (fir)
  2. Acer (maple, mosts species)
  3. Aconitum (aconite)
  4. Alchemilla (lady’s mantle)
  5. Allium (ornemental onion)
  6. Amelanchier (serviceberry)
  7. Aquilegia (columbine)
  8. Asclepias (milkweed, some species)
  9. Astrantia (masterwort)
  10. Baptisia (false indigo)
  11. Buddleia (butterfly bush)
  12. Caltha (marsh marigold)
  13. Caryopteris (bluebeard)
  14. Cercis canadensis (redbud)
  15. Chelone (turtlehead)
  16. Cimicifuga (bugbane)
  17. Clematis (clematis)
  18. Cornus (dogwood)
  19. Corydalis (fumitory)
  20. Delphinium (delphinium)
  21. Dicentra spectabilis, now Lamprocapnos spectabilis (bleeding heart)
  22. Dictamnus (gas plant)
  23. Dodecatheon (shooting star)
  24. Echinacea (purple coneflower)
  25. Eremurus (foxtail lily)
  26. Eryngium (sea holly)
  27. Eupatorium (Joe Pye weed)
  28. Filipendula (meadowsweet)
  29. Forsythia (forsythia)
  30. Fragaria (strawberry)
  31. Fuchsia (fuchsia)
  32. Gentiana (gentian)
  33. Geranium (perennial geranium, cranesbill)
  34. Goniolimon (German statice)
  35. Helianthemum (rock rose)
  36. Helianthus (perennial sunflower)
  37. Heliopsis (false sunflower)
  38. Helleborus (Christmas rose)
  39. Hemerocallis (daylily)
  40. Heuchera (coral bells)
  41. Hibiscus moscheutos (perennial hibiscus)
  42. Hypericum (St. John’s wort)
  43. Iberis (perennial candytuft)
  44. Ilex* (holly)
  45. Incarvillea (hardy gloxinia)
  46. Iris (iris, many species)
  47. Kirengeshoma (waxbells)
  48. Knautia (knautia)
  49. Lathyrus (perennial sweet pea)
  50. Lavandula (lavender)
  51. Leontopodium (edelweiss)
  52. Lobelia (hardy lobelia)
  53. Lonicera (honeysuckle)
  54. Macleaya (plume poppy)
  55. Magnolia* (magnolia)
  56. Malus (apple, crabapple)
  57. Mazus (creeping mazus)
  58. Mertensia (Virginia bluebells)
  59. Muscari (grape hyacinth)
  60. Myrrhis odorata (sweet cicely)
  61. Nepeta (catmint)
  62. Oenothera (evening Primrose)
  63. Opuntia* (beavertail cactus)
  64. Paeonia* (pivoine)
  65. Penstemon (beard-tongue)
  66. Persicaria (fleeceflower)
  67. Persicaria orientalis, syn. Polygonum orientale (kiss-me-over-the-garden-gate)
  68. Phlox (phlox)
  69. Physalis (Chinese lantern)
  70. Picea (spruce)
  71. Platycodon (balloon flower)
  72. Primula (primrose)
  73. Pulsatilla (pasque flower)
  74. Quercus (red and black oaks)
  75. Ranunculus (buttercup)
  76. Ratibida (prairie coneflower)
  77. Rosa (rose)
  78. Rudbeckia (black-eyed Susan)
  79. Sambucus (elderberry)
  80. Sanguinaria (bloodroot)
  81. Sanguisorba (burnet)
  82. Saponaria (soapwort)
  83. Saxifraga (saxifrage)
  84. Scabiosa (pincushion flower)
  85. Sedum (stonecrop)
  86. Sempervivum (houseleek)
  87. Sidalcea (prairie mallow)
  88. Staphylea* (bladdernut)
  89. Stokesia (Stokes’ aster)
  90. Syringa (lilac)
  91. Thalictrum (meadow-rue)
  92. Tiarella (foamflower)
  93. Tricyrtis (toad-lily)
  94. Trillium* (trillium)
  95. Trollius (globeflower)
  96. Tsuga (hemlock)
  97. Vernonia (ironweed)
  98. Veronica (speedwell)
  99. Viola (violets)
  100. Vitis (grape, some species)
*Some species in this genus require a double cold stratification: that is, two cold treatments separated by warm one, to germinate well. Try two to three months of cold followed by two months of warmth, then again two to three months of cold. When you expose them to warmth after these repeated treatments, most will germinate quite readily.

Good growing!20180103 ENG worldartsme.com, rdkate.blogspot.ca & mzayat.com.jpg

6 Perennials for Spectacular Fall Color

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Cushion mums are as spectacular in bloom as any summer perennial. Photo: Rachel Kramer, flickr

You thought the gardening season was over by September and all you had to do was hang up your gardening tools? Think again! Thanks to climate change, in most regions autumns are longer and warmer than ever and that has extended the flowering season well into November, often even December.

Bulbs (colchicums and autumn crocuses), shrubs (several hydrangeas, seven-son flower [Heptacodium] and common witch-hazel) and many annuals (pansies, snapdragons, hybrid sweet alyssums, etc.) will continue to bloom right through the fall, even sailing through the first light frosts. They won’t stop until a truly hard frost hits. In fact, some annuals, like ornamental cabbage, don’t even start to show color until September. But there are more fall-flowering varieties among perennials than in any other group.

Here are six of the best!

Garden Mums

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Hundreds of years of hybridizing have led to the popular “cushion mum,” with a dense, dome-shaped habit and hundreds of flowers. Photo: pixabay

There are currently about 20 species of Chrysanthemum, commonly called chrysanthemums or just mums, and all are fall bloomers. However, just because they are sold locally doesn’t mean they are hardy in your region.

Many merchants make little difference between florist chrysanthemums (frost-tender varieties) and garden mums (hardy varieties) and sell pots of both in the fall. The two, after all, belong to the same species (Chrysanthemum × morifolium, formerly C. × grandiflorum and Dendrathema × grandiflorum), a complex hybrid with both hardy and subtropical species in its background. Florist and garden mums may therefore appear to be identical, but florist varieties are often only hardy to zone 8 whereas hardy garden mums are solid in gardens as cold as zone 3. That’s a huge difference!

So, how can you tell the two apart in a store display?

In box stores, supermarkets or other non-specialist venues, you can’t. Chances are all the mums they sell are florist varieties, shipped in from the South in full bloom for rapid fall sales. They’re essentially annuals in most gardens. However, garden centers and plant nurseries  usually offer both garden and florist types. To find out which is which, ask about guarantees. Truly perennial mums will have a 12-month guarantee; tender florist mums won’t.

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Hardy chrysanthemum Mammoth Red Daisy is a big one, as large as many shrubs! Photo: Ball Horticultural Company

There are some very good garden mums (i.e. hardy cushion mums) out there, varieties known for their resistance to extreme cold, and this includes the Morden, Minn, Firecracker and Mammoth™ series (the latter was formerly known as the My Favorite™ series and that name may still be used by some nurseries). The four series offer single and/or double varieties in a wide range of colors: yellow, orange, pink, purple, white, etc. The Morden and Minn mums are dwarf plants (12-18 inches x 18-24 inches/30-45 cm x 45-60 cm) covered with flowers from September to frost, while the Mammoth series mums are taller and wide: 3 to 4 feet (100-120 cm) tall and wide. Firecracker series mums (Power Surge®, Showbiz®, Suncatcher®, etc.) are of intermediate size.

All varieties mentioned are hardy to zone 3. Sun or partial shade.

Heirloom Mums

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The most popular heirloom mum is ‘Clara Curtis’. Photo: rosekennedygreenway.org

There are also heirloom mums, also called old-fashioned mums or rubellum mums. They’re a different species: Chrysanthemum × rubellum, formerly C. zawadskii latilobum.

This group includes the well-known ‘Clara Curtis’ (pink, zone 3), ‘Duchess of Edinburgh’ (dark pink, area 4) and ‘Mary Stoker’ (yellow, zone 3), plus half a dozen others. All produce simple daisylike flowers with a yellow center. They reach about 18 to 30 inches (45-75 cm) in height and diameter, depending on the cultivar, but have more finely cut leaves than garden mums and certainly don’t form the dense mounds typical of cushion mums. Instead they have a much more open habit and are even inclined to wander a bit. They’re not really invasive, though, as it’s easy to pull out stragglers if they go too far.

Zone 3. Sun or partial shade.

You can read more about hardy mums here: Chrysanthemums for Cold Climates.

Asters

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New York aster ‘Patricia Ballard’. Photo: dorsetperennials.co.uk

North American fields and forests are full of wild asters in shades of violet and white, but there also are many cultivated asters to be discovered, including New England asters (Aster novae-angliae, now Symphotrichum novae-angliae) and New York asters (A. novi-belgii, now S. novi-belgii). They have larger flowers in a much wider color range than wild asters. They come in shades of violet (so-called blue), purple, pink, red, and white, often with semi-double or double flowers.

Until recently, most asters were tall to medium-height plants for the back or the middle of the garden. A. n-a. ‘Harrington’s Pink’ (pink, 48 inches x 24 inches/120 cm x 60 cm) and A. n-b. ‘Patricia Ballard’ (dark pink, 36 inches x 15 to 20 inches/90 cm x 40-50 cm) are examples of these popular taller varieties.

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Aster ‘Purple Dome’. Photo: Footprints Plants, LLC

Dwarf asters, although often sold under the botanical name A. dumosus (a name that really belongs to a summer-flowering Eurasian species), are actually just smaller selections of A. novae-angliae and A. novi-belgii. A. n-a. ‘Purple Dome’, for example, is popular, forming a rounded dome 16 to 20 inches (40-50 cm) in height and width with purple flowers. The Wood’s series of dwarf asters is similar, but comes in other colors.

Fall asters are hardy to zone 4, sometimes in zone 3. Sun or partial shade.

Goldenrod

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Solidago rugosa ‘Fireworks’. Photo: F. D. Richards, flickr

There is a surprising dichotomy between the attitude of North American and European gardeners towards goldenrod (Solidago spp.). North Americans tend to see goldenrods, which are native to their continent, as weeds and want little to do with them. Europeans, on the other hand, for whom they are exotic plants coming from the New World, adore them!

I find it almost criminal to malign these gorgeous perennials with their rich yellow flowers simply because they’re natives when, in fact, they are among the best fall perennials. True enough, Canada goldenrod (Solidago canadensis) is highly invasive species in gardens, both through seeds and wandering rhizomes, but the others are clump-forming and stay put. If you don’t believe me, try S. × ‘Crown of Rays’ (23-27 inches x 18-23 inches/60-70 cm x 45-60 cm), S. × ‘Dansolitlem’ Little Lemon® (12-18 inches x 12-23 inches/30-45 cm x 30-45 cm) or S. rugosa ‘Fireworks’ (36-48 inches x 36 inches/90 to 120 cm x 90 cm), all with stunning feathery yellow flowers. Beautiful!

Zone 3. Sun or partial shade.

Autumn Sedum

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Sedum ‘Herbsfreude’. Photo: laidbackgardener.blog

Autumn sedum, also called autumn stonecrop, showy sedum or showy stonecrop (cultivars and hybrids of Sedum spectabile [Hylotelephium spectabile] and related species), is a fairly low-growing plant (rarely more than 2 feet/60 cm tall), with succulent stems and leaves, often bluish green. The star-shaped flowers are produced in dense masses, a bit like colored cauliflower, and come in shades of pink, red or white, more rarely, pale yellow. They’re one of the last fall feeding stations for butterflies.

S. ‘Herbsfreude’ (‘Autumn Joy’), 12-24 inches x 18-24 inches (60 cm x 45-60 cm), is best known and bears pink flowers turning brownish red. S. ‘Autumn Fire’ is similar, but more compact (20 inches x 18-24 inches/50 cm x 45-60 cm). A sturdier plant, it doesn’t tend to flop under the weight of its flowers the way ‘Herbstfreude’ may do. S. ‘Purple Emperor’ (16 inches x 18-24 inches/40 cm x 45-60 cm) is just one of many autumn sedums with dark purple leaves and pink flowers, while ‘Elsie’s Gold’ (16-18 inches x 20-24 inches/40-45 cm x 50-60 cm) has green leaves with yellow to cream edges and magenta flowers. It’s less likely to flop than most other variegated autumn sedums.

There are dozens of other excellent varieties.

Zone 3. Sun.

Turtleheads

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Chelone lyonii ‘Hot Lips’. Photo: laidbackgardener.blog

Turtleheads get their curious name from their flowers, said to look like a turtle’s head. In fact, their botanical name, Chelone, comes from the Greek and also means turtle.

Red turtlehead (Chelone obliqua) is probably the most common variety. It produces a dense, non-invasive clump of solid, perfectly erect stems 24-36 inches tall on a plant 24 inches in diameter (60-90 cm x 60 cm). The very dark green leaves are attractive all summer, but the beautiful deep pink flowers dominate in the fall.

Lyon’s turtlehead (C. lyonii) is very similar in all respects: you can scarcely tell it apart from pink turtlehead (C. obliqua). C. lyonii ‘Hot Lips’ (60-90 cm x 60 cm) is very popular with darker leaves than the species. C. lyonii ‘Tiny Tortuga’ is a dwarf variety only 12-15 inches tall and 8-10 inches in diameter (30-40 cm x 20-25 cm).

Zone 3. Sun or shade.

Maiden Grass

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Miscanthus ‘Purpurascens’. Photo: laidbackgardener.blog

This tall grass (Miscanthus sinensis) is very popular, grown for its arching green ribbon-shaped leaves that become straw-colored in fall and its blooms that start pinkish to become silver-white as fall progresses. Both leaves and flowers hold on right through the winter into spring, offering six months or more of interest.

In zone 7 and above, maiden grass can self-sow and become invasive due to overseeding, so look for near-sterile varieties like ‘Autumn Light’ and ‘Morning Light’ as well as any of the variegated cultivars, as they almost never bloom.

Seeds don’t mature in cold climates, so maiden grass isn’t invasive there … but it might not perform well there either. Its hardiness varies from zone 4 to 6, so make sure you choose one cold resistant enough for your conditions. Also, some cultivars won’t have time to bloom in short-season climates or will only bloom occasionally in years where the summer was extra-long. Unless your local merchant is a specialist in ornamental grasses, you won’t be warned about this fact, so research your plants ahead of time.

Best choices for bloom in colder climates include the extra=hardy Huron series, including M. s. ‘Huron Sunrise’ (6 feet x 2-3 feet/180 cm x 60-90 cm), zone 3, the popular tall cultivar M. s. ‘Silberfeder’ (7-8 feet x 4 feet/200-250 cm x 120 cm), zone 4, and purple maiden grass (M. ‘Purpurascens’), 5 feet x 2 ½ to 3 feet (150 cm x 75-90 cm), also zone 4. The latter offers distinctly coppery foliage color in fall.

Sun or partial shade.

Even More Fall-bloomers

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Add the right fall-bloomers and your autumn garden will come alive!: Photo: autumnasters.co.uk

There are still many other perennials that bloom in fall: boltonia (Boltonia), Japanese anemone (Anemone × hybrida), helenium or sneezeweed (Helenium), bugbane (formerly Cimicifuga, now Actaea), ironweeds (Vernonia), tall coreopsis (Coreopsis tripteris), Joe-pye weeds (Eupatorium), perennial sunflowers (Helianthus ‘Lemon Queen’ and others), black-eyed susans (Rudbeckia), monkshoods (Aconitum), echinaceas (Echinacea), and many more.

As you can see, with the right choice of plants, there is no reason why your garden can’t be as spectacular in October as it was in July!20170911a-rachel-kramer-flickr

Ironweed : Truly Tough as Nails

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Vernonia noveboracensis

Although ironweed (Vernonia spp.) is not exactly an unknown perennial, it certainly doesn’t have the popularity it deserves. It’s one of those plants you see in plant nerd’s gardens and in those public gardens that have an “in-the-know” gardener behind the scenes, the kind of plant you find strikingly attractive, but just can’t put a name on. I think it’s time for us plant geeks to change that.

i’ve been growing ironweed for a number of years now, first New York ironweed (Vernonia noveborecensis), at the time, the most widely available species, then others. North American ironweeds are mostly upright, clustering perennials with strong stems forming a somewhat flaring clump. They bear long, lance-shaped, dark green leaves all the way up an often reddish stem and, for about 6 weeks somewhere between August to October, depending on your local climate, clusters of fuzzy purple flowers at the top of the stems. Actually, the “flower” isn’t really a flower, but an inflorescence, a cluster of much smaller flowers forming a tight head.

Unlike many other plants in the Aster family, ironweed inflorescences have no rayflowers (the broad “petals” of daisies, black-eyed Susans, and sunflowers). Instead, all the tiny florets are narrow and tubular… and all are the same purple colour.

Clustered flowers almost always attract butterflies and that is certainly the case with ironweed: it is one of the best butterfly plants for the end-of-summer/fall garden.

What’s in a Name?

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Rusty brown seed heads of Vernonia fasiculata add winter interest and attract birds.

I always assumed ironweed got its name because its tough stems never flop. Some botanists agree with that theory, but others suggest the name is due to the rusty brown colour of the fuzzy seed heads that follow the plants bloom and hang on into winter. The fact is no one knows why early North American colonists gave this plant its common name. The origin of the botanical name, though, is known: it honours William Vernon, a British botanist who collected plants in Maryland in 1697 and 1698… and brought back the first ironweeds to Britain.

A Huge Genus

The genus Vernonia is a huge one, with over 1,000 species, including trees, shrubs and perennials, and is found in Asia, Africa and North and South America. The species that will interest northern gardeners, though, are all hardy perennials, with no shrublike qualities, and are from the North American branch of the genus, a group of some 20 species. All have the same fuzzy purple flowers and are best told apart by their height and foliage characteristics.

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Vernonia noveboracensis

The first species to be commercialized was the New York ironweed (V. noveboracensis), native to the east coast of the United States. It is a tall as perennial perennials go, averaging 4 to 6 feet (120-180 cm), but you’ll soon see that that is only of intermediate height for a vernonia. It is hardy to zone 3.

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Vernonia fasciculata

Prairie ironweed (V. fasiculata) is not that different from V. noveboracensis, although a bit smaller on average (3 to 4 feet/90-120 cm). As the name suggests, it is native to the Prairies as far north as Manitoba. It is the most drought-tolerant of the ironweeds. Zone 3.

Arkansas ironweed (V. arkansana) is not as limited in its distribution as the name suggests, but rather is a species of US Midwest states. It is often sold under the name V. crinita. It has broader leaves than most ironweeds and attains 4 to 6 feet (120-180 cm) in height. The best known cultivar V. a. ‘Mammuth’, which, as the name suggests, is a taller selection, up to 7 feet (210 cm). Zone 3.

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Vernonia giganea ‘Purple Pillar’

The tallest of the ironweeds is called, appropriately, giant ironweed (V. gigantea, formerly V. altissima). It can reach from 5 to 10 feet (1.5 to 3 m) in height: a true giant among perennials! It is the most upright vernonia of all, almost like a pillar, and therefore less vase-shaped than the others. Also, it has broader, longer leaves than other ironweeds… but still the same purple flowers as its cousins. Give this one moister soil than the others or supply a bit of shade: in the wild, it tends to be a woodland species and doesn’t like to dry out. It has a very wide distribution in nature, throughout the eastern half of the US and into Ontario. There is a cultivar, ‘Purple Pillar’, which seems to be identical to the species. Zone 3.

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Vernonia lettermannii ‘Iron Butterfly’

Narrowleaf ironweed (V. lettermannii) breaks most of the ironweed rules. First, it is fairly short, only about 2 to 3 feet 3 inches (60 to 100 cm) tall. Its leaves are very narrow indeed, almost threadlike, and very numerous, giving this plant a very ferny look. Also it forms a much more rounded plant than the other ironweeds, with a distinctly less upright silhouette. Narrowleaf ironweed is very rare in the wild, found only sporadically in Arkansas and Oklahoma, but is quickly becoming the commonest ironweed in gardens, especially the cultivar ‘Iron Butterfly’. The latter actually doesn’t differ much from the wild form, except that it is of a more stable height: about 3 feet (90 cm). Zone 4.

Growing Ironweeds

As the name suggests, ironweeds have an ironclad constitution. They are tough and sturdy, never requiring staking, and, in fact, need essentially no care other than trimming the old stems back in spring (leave them up all winter: they’ll attract seed-eating birds!). In the wild most species are found in grasslands and abandoned fields in average to fairly rich soil. In the garden, they’ll prefer full sun to no more than partial shade. They do fine in the richly amended soils of most gardens, but won’t fuss if you plant them in plain old “dirt”. Ironweeds are drought-resistant to a certain degree (especially prairie ironweed), but prefer fairly even moisture. They’re not considered invasive, but they may produce a few offsets over time and all can self-sow, but usually only do so to a limited degree.

The most obvious way to multiply ironweeds is by division, best done in spring, but they also sprout readily from stem cuttings taken at the same season. Seed germinates readily if you sow it outdoors in the fall. If you choose to sow it indoors, after sowing, place the pots in a sealed plastic bag and refrigerate for 2 months, as they need a period of cool temperatures and moist soil conditions in order to stimulate germination. When the 2 months are up, expose them to light and the seeds will soon sprout.

You’ll find that better garden centres now offer ironweeds (V. lettermannii ‘Iron Butterfly’ is becoming particularly popular), but if you can’t plants locally, try mail order sources.

Easy, colorful and tough-as-nails, ironweeds deserve a place in every garden!