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, &

Christmas Roses in Bloom Soon?




A typical “Christmas rose” (Helleborus niger) in spring.

Yes, hellebores (Helleborus spp. and especially the very early H. niger) are often called Christmas roses. That’s because, in mild climates, these perennials start to bloom as early as January. But not where I live. Where winters are cold, as in most of North America, this hardy perennial rarely blooms before the month of March, even April or May (the latter for me)… but this winter may be the exception. With mild weather apparently continuing well into January in most of the Northern Hemisphere (see How Will This Mild Weather Affect Our Plants?), who knows? Maybe your hellebores are budding up as we speak.

I won’t be seeing that this year: where I live (Quebec City), nearly a foot of snow has fallen over the last week, putting a definitive end to this year’s prolonged fall season, but I realize that my region is one of the few that is white right now. For many of the readers of this blog, mild temperatures are still the norm and seeing Christmas roses bloom this January is therefore very much a possibility.

Christmas Roses for Christmas!


A forced hellebore on sale at Christmas.

But there’s another way to seed Christmas roses in flower at Christmas: you can buy a plant already in bloom. Yes, in better garden centers, you’ll see hellebores offered in full bloom during the holiday season, and they actually make great Christmas plants, with blooms lasting well into until March if you offer them a minimal amount of care.

The instructions accompanying each plant explain its basic needs: keep the plant well watered and put it in a bright location, preferably on the cool side, then plant it outdoors in the garden in spring as a perennial.

Personally, I was more than a bit skeptical about this information. How could a hardy perennial that normally requires a cold winter be able to spend a winter in an overheated home and still be alive come spring? Sure, the information might be valid in Europe or in milder parts of North America, where you could potentially plant it outdoors as soon as February, but in climates like mine, where snow falls early and hangs around for months, you probably won’t be able to plant the poor thing outdoors before May: that means three extra months of warm temperatures for a plant that is used to a long, cold winter!

My Experience

To assuage my doubts, I obviously had to try growing one. So five years ago, in early December, I purchased a Christmas hellebore in full bloom with dense clusters of pure white flowers. I actually used it as a table decoration for the entire Christmas period. After the holidays, I simply put it with my other houseplants on a windowsill, giving it no special treatment, not even particularly cool temperatures. And to my surprise, it did fine!

My hellebore remained in bloom until mid-March, although the sepals did gradually turn green. The foliage was still in mint condition in May when I finally was able to plant it outdoors. And since then, every spring after the usual long, snowy winter, it has bloomed perfectly, from early May until July.


When you buy hellebores in the spring, you have a wider choice of colors.

Would I repeat the experience? Probably not. I love hellebores and grow dozens of them outdoors, but the ones sold at Christmas cost many times more than the ones I receive by mail order in spring. And there is essentially no choice during the Christmas season: I’m used to being able to choose from varieties with white, purple, red, pink, yellow or green flowers, single or double, with or without spotting. At Christmas, all I can find are plain white ones… and I already have plenty of those in my shade garden.

Making Hellebores Happy

Whenever you do buy hellebores, at Christmas or in spring, you’ll want to plant them outdoors in a forest setting or some other spot under deciduous trees so that they will be shaded in the summer but get a fair amount of sun in spring. They prefer rich, well-drained soil that is not too acidic. In cold climates (zones 3 to 5), give them a thick covering of dead leaves in the fall, otherwise their foliage, theoretically evergreen, may be killed by the cold. Of course, even if the leaves do die back, that won’t stop the plant from blooming in early spring… and fresh, healthy leaves will sprout with the flowers.

Harder-working gardeners then I remove damaged leaves in the spring and cut back the flowers when they fade. Personally, I give my hellebores no care whatsoever, at least, once they’re well established. Yes, I do confess to watering them in times of drought during their first summer, but after that, they get no watering, no fertilizing, no cleaning, nothing… and they positively flourish! And they are deer resistant too! In fact, few perennials are as easy to grow. And most species and hybrids will pretty much live forever (H. foetidus is an exception: it only lives 2 or 3 years, but it compensates by self-sowing).

Their hardiness varies though: some are hardy to zone 3, others not beyond zone 7, but in general, most hybrid hellebores will be tough enough to survive in zone 4, at least in climates where snow cover is abundant.

So the choice is yours: buy a hellebore in full bloom for Christmas or wait until spring for a wider choice and better prices. Either way, hellebores are superb plants you really should be trying if you have a shady nook in your garden. And keep an eye on your garden in January if the weather continues to be mild… you never know!