Only January, Yet Already Time to Sow Seeds?



20180103 ENG, &

It’s only January! Surely it’s too soon to sow seeds? Source:, & 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!


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.


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

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


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, &

Beautiful Flower, Strange Name


Chelone obliqua

Among the stars of the fall garden is a truly unique perennial, the turtlehead (Chelone spp.). What I love about this plant, besides its long-lasting flowers, is its perfect behavior. It never runs, flops, or fades, standing firm in the worst wind and the deepest shade. If only all the plants were as well behaved!


The curious flower is said to resemble a turtle head!

At the very end of the summer and throughout the fall, fat tubular pink to white flowers appear on short spikes atop each stem. The blooms are odd enough in appearance, almost closed at the tip with an opening resembling a beak. They’re said to look like the head of a turtle, whence both the common name and the botanical one, as Chelone (pronounced “kay-LOH-nee”) is Greek for turtle.

The curious flower is designed to let only the strongest pollinators enter, notably bumblebees and hummingbirds. Even so, you’ll often see butterflies stopping by, trying to steal a bit of nectar with their long proboscis.

Turtleheads leaves have opposite leaves with each pair placed at a 90 degree angle to the pair below, giving the effect of a cross when you look at the plant from above. Their stem is square, a trait unusual in their plant family, the Plantaginaceae (foxglove family), but one shared with at least one close relative, the obedient plant (Physostegia virginiana).

There are only four species of turtlehead, all from eastern North America. The following three are the most widely available to home gardeners.

Red Turtlehead (C. obliqua)


Chelone obliqua

In spite of its common name, the deep pink flowers of this species not really much darker than those of the so-called pink turtlehead (C. lyonii) with which it is often confused. This species is native to eastern and central United States, although absent from New England.

Red turtlehead forms dense clumps of upright unbranching stems bearing large, lightly toothed, lanceolate leaves of a very dark green shade. The leaves have a short petiole, an apparently minor detail, but one worth pointing out, as that is what distinguishes it from C. lyonii.

Red turtlehead reaches about 2 to 3 feet (60 to 90 cm) in height. As with the other turtleheads, it begins to bloom at the very end of summer and continues for a good 2 months, right through fall in many locations. It is hardy to zone 3.

There is also a supposed white-flowered cultivar of this species called ‘Alba’… but it is likely just C. glabra, described below.

Pink Turtlehead (C. lyonii)

Chelone obliqua

Chelone lyonii

Essentially identical to C. obliqua from a gardener’s point of view, with the same pink blooms, you can identify pink turtlehead by the slightly longer leaf petioles. It is also somewhat taller (2 to 4 feet/60 to 120 cm) than C. obliqua.


Chelone lyonii ‘Hot Lips’

The most common cultivar of this species is ‘Hot Lips’, which is a more compact plant: about 2 to 3 feet (60-90 cm) in height. Its flowers are a darker pink and its stems are reddish.

‘Tiny Tortuga’ is a 2014 introduction, with dark pink flowers. Very dwarf, it reaches only 14 inches (35 cm) high.

There is also another dwarf variety, ‘Pink Temptation’, about 16 inches (40 cm high). All these plants are hardy in zone 3.

White Turtlehead (C. glabra)


Chelone glabra

This is the most widely distributed turtlehead, found throughout much of eastern and central North America well into Canada. It is easily distinguished from the others by its white to white tinged pink flowers. Also, the leaves are narrower and sessile (they have no petiole at all).

Although a plant of swampy woodlands in the wild, white turtlehead grows very well in ordinary garden soils. Its height is highly variable, from 3 to 6 feet (90-180 cm): it grows tallest in water-logged soils. Although native well into the North, it seems no hardier than the southern species: zone 3.

I find this species the least interesting turtlehead for the flower border, because its flowers are less dense, tend to brown quickly and its habit is more open and less sturdy. It is even a bit invasive.

There is also a cultivar, C. glabra ‘Black Ace’, with extra dark foliage, almost black, and the denser flowers. Also zone 3.

Japanese False Turtlehead (Chelonopsis yagiharana)


Chelonopsis yagiharana

Chelonopsis is the Asian counterpart of the genus Chelone, with a very similar habit and foliage, but its tubular flowers are distinctly trumpet-shaped and thus look nothing like a turtlehead. The lower lobe is substantially longer and wider than the upper one.

There are over 15 species, but the only one I have seen offered is C. yagiharana, from Japan. This species is quite compact: about 1 to 2 feet (30-60 cm) in height. Its exact hardiness is not known yet, but it seems to perform well in zone 4. It is as yet rarely offered.

Growing Turtleheads

One nice thing about turtleheads is that they are a snap to grow and you never hear complaints about them.

They like soil rich in organic matter that is always a bit humid. They tolerate poorly drained soils and can thus grow along the edge of a water garden. Water them in case of drought, however, as their drought tolerance is limited. A good mulch to keep their soil more evenly moist would be appreciated.

They are not very heavy feeders and will get along fine with an annual application of compost.

Turtleheads seem to grow equally well in sun or shade… and how often can you say that about a plant! In the wild, they are often found in dense forests where little light penetrates, but also in swamps out in full sun. Just make extra sure they are well-mulched if you want to grow them in a sunny location.

Most species of turtlehead form a dense clump that expands ever so slowly in diameter, so keeping them in their place is not complicated. White turtlehead is the exception, a faster grower with a more invasive nature and may require more frequent division.

For quick and easy multiplication, try taking stem cuttings. You can also divide the plants, preferably in the spring, but also in the fall.



Baltimore Checkerspot

Turtleheads are the primary host of the beautiful Baltimore Checkerspot butterfly, but the damage is usually limited to a few leaves and thus easily forgiven. And even though they often they grow in damp environments where slugs are numerous, the latter seem to have no interest in turtleheads.

Sadly, white-tailed deer are crazy about this plant: if you have a problem with this mammal in your yard, turtleheads will not be a good choice for your flowerbeds!

Where to Find Them?

Turtleheads are quite widely available and most garden centers and nurseries will offer at least one variety, although you’re not likely to find the whole range of species and cultivars in a single spot. For specific cultivars you can’t find locally, try a mail order source.

Turtleheads: their odd name belies an ease of culture well worth discovering, certainly one of the best fall-blooming perennials.