What to Winter-Sow and When | Updated 2020. YOU MIGHT WONDER WHEN, exactly, to winter-sow your perennials, annuals, herbs and veggies outdoors. The easiest answer is “now.” However, depending on where you live, you may find that it pays to plant certain seeds ahead of others. The following schedule has worked well for me:
Perennials and Hardy Annuals
As a rule, if a plant is hardy in your zone, you can plant its seed any time in winter, regardless of the temperature outside. Sprouting will occur when warmth arrives, normally in spring. However, the seed can also sprout during some freak warm spell between weeks of frigid conditions. This is not a problem for perennials and hardy annuals. They simply yawn in the face of frost.
You can plant these early, too, with one important caveat: Should sprouting occur during a warm day (and remember, it’s even warmer inside the milk-jug greenhouse), you’ll have to throw a blanket over the container at night because such seedlings are easily killed by frost. That’s why they’re called “tender.” Consequently, to avoid the covering-work, it pays to delay the sowing of tender annuals until March or April.
Winter Sowing Schedule
Last year, in my own, zone 5-b garden, I planted perennials, annuals, herbs and vegetables using the following time-table. All of the seeds sprouted and survived (except the Delphiniums, probably because the seeds were old).
January through February:
Flowering Perennials & Hardy Annuals
Digitalis purpurea (Wild Foxglove)
Oenothera speciosa (Evening Primrose)
Consolida (Larkspur) ‘Galilee Blue Double’
Aquilegia (Columbine) ‘Alpina’ blue
Aconitum carmichaelii (Monkshood)
Delphinium grandiflorum ‘Blue Mirror’
Nepeta ‘Pink Dreams’ pink
Oenothera lamarkiana yellow
Alcea (Hollyhock) ‘Camois Rose’ rosy-pink
Alcea ‘Apple Blossom’ pale-pink
Berlandiera ‘Chocolate Flower’ yellow, fragrant
Campanula (Bellflower) ‘Champion Pink’
Campanula latifolia ‘Brantwood’ purple
Nicotiana ‘Fragrant Cloud’ and ‘Purple Perfume’ (I also sowed these indoors, under lights; both grew with equal exuberance)
Platycodon (Balloon Flower) ‘Sentimental Blue’ (pictured above)
Lupinus (Lupine), ‘Russell Hybrids Mix’
Centaurea cyanus (Bachelor Buttons) common blue variety
Vegetables & Herbs
Thymus serpyllum (Creeping Thyme)
Salvia (common sage)
Again, this planting schedule is based on my own, zone 5-b climate. If you live in a milder zone you can winter-sow your seeds much earlier than me. I know a Texan who winter-sows his tomatoes in December.
And by the way, have you tried my Tomato Pie yet? Here’s the ridiculously-simple recipe.
Well. I hope this post was helpful to you in some small way. It’s fun to plant our gardens at the “wrong” time of the year!