Fall/Winter Seed Sowing
By Patrick Ryan, Education/Outreach Specialist Alaska Botanical Garden
Definition: a way to start seeds outdoors during the Fall and Winter.
NOT Direct Seeding-less control in garden
Activity Levels: You will find that start-up is easy and requires few supplies and
moderate level of activity. During the Winter there is low level of activity. In the
Spring there will a higher level of activity. We’ll discuss this later.
Benefits:
Follows Nature’s method-stratification (periods of cold help crack seed coat).
Some seeds grown indoors might also require scarification (nicking seed coat)
or soaking.
No additional lighting required
Does not take up indoor space (greenhouse, kitchen table, bed, etc.)
Control over where plants will grow (as opposed to broadcasting seeds)
No hardening-off needed-already acclimated
Get started:
You will need:
Clean, clear or translucent container with holes, or add holes. Juice jug, seed
flat, etc. (Lets light, air and water in, excess water out).
Soil-any used container soil is fine (seed-starting mix too light)
Seeds-perennials, biennials, native plants. Other: herbs etc.
Water source (most important in Spring)
Utility knife, and/or scissors, and/or drill
Tape. I use clear plastic packing tape
Sharpie, pencil, plant labels
Container: 2 things in, one thing out: air and water in, excess water out.
(What is the L.A.W.?) Light, Air, Water
Cover/no cover. Might be better in Spring for germination to cover. No weeds
in.
Seed Trap is a flat or other container set outdoors uncovered with soil for
the purpose of “trapping” wind-borne seeds, e.g. birch, spruce, fireweed,
dandelion, etc.
Old seed flats work well for me. I use flats with holes and/or old cracked
trays that can nest inside the netted-type of flat.
”Daisy Trays”
I do not generally cover my flats. Just leave outside and make sure they have
snow cover. Weed seeds may blow in.
Translucent or clear water and juice jugs work well. Leave the lid off so rain
and snow will go in. Add bottom holes for drainage. Cut around the jug about 4
inches from the bottom, leaving the handle as a hinge. Add soil, water, seeds,
label and tape it shut. Any clear deli-type containers work well.
Soil: Use recycled soil from old containers. Pests will not live through Winter
outdoors. Mixed soil is good. Moisten soil to get things started. Add soil at least 2
inches deep in container, with “headroom” for seedling growth, as in seed flat with
clear lid, clear deli tubs, “clamshell” deli container, etc.
Fruit and produce containers may have holes-strawberries, raspberries. Perfect!
Smaller containers dry our sooner. More work in Spring.
Seeds: after soil is in your container, it’s a good time to water before adding the
seeds. Sow seeds thinly on the surface on the soil so you don’t need to thin much
later. Small seeds can be mixed with sand for more even distribution.
Some seeds require light for germination, and some require darkness. In general,
smaller seeds should just be pressed onto the surface of the soil for good seed-tosoil contact. Larger sees can be pushed in with a pencil (eraser end) to a depth of 12 times their thickness. Cover thinly with sand or light soil mix. You will discover in
time which methods work best for you. Primroses seem to do well on a grit surface,
for example. A good book on the subject is The New Seed Starters Handbook by
Nancy Bubel.
If sowing mixed seeds in one container, you may have different germination
requirements, such as planting depth, light/no light, temperature, etc. but it’s worth
a try. View Winter seed sowing as a fun science fair project.
After sowing, tape on lid and add a label. Write on the recycled deli containers with
a permanent marker. You can add a traditional white plant label for the inside too.
Use pencil or a special label marker. With seed flats, put label between the nested
flats so they don’t blow away. You could color code your seed trays using colored
labels if that makes you happy.
Focus today is on perennial plants. Remember: don’t plant a problem! (Invasive
plants). I encourage you to look into planting more native species as they will
attract pollinators and wildlife, and they will be easier to care for.
Spring: Yes, it will come! This is the season of high activity. Daily monitoring of
containers is a good idea as the snow melts. The key is adding water if soil is dry. As
the sun warms the containers, you should see condensation on lids. If not, soil is
too dry. You can open the lids as the days warm into the 50s but you may want to
close them at night if below freezing. Chopsticks work great for propping lids open.
At the very least, walk by the containers daily. Add water if needed.
If you want to jump start the process, you can bring the containers into the
greenhouse or home and warm them up to start Spring off a little earlier. Most
seeds need a minimum of 4 weeks chilling, and some as much as 12 weeks. You would
do well to add bottom heat with a propagating mat, and you will need to add
supplemental light as the seeds sprout.
If you’ve sown your seeds thinly, they may not require transplanting for quite a
while. The rule of thumb is to transplant seedlings when they have their first set of
true leaves.
NOTE: poppies do NOT transplant well. Allow them to grow to several inches and
then gently plant the whole mat of seeds and soil. You can have a hole prepared, or
mound up soil around the mat. Keep moist until settled.
Keeping records/or not. Here is a site I found for a free download of a gardener’s
journal: http://www.arbico-organics.com. Look under the Resources tab to find the
journal. You can design your own journal too. You should do what makes sense to you.
EXTRA! The produce tubs with lids and no holes make great mini-greenhouses for
indoor planting in the Spring . Great for a classroom windowsill and they will not
leak. Same procedure: add at least 2inches of clean soil, leaving “headroom” for
seedling, moisten, and add thinly-sown seeds. Put the lid on and label with a
permanent markers. When the seeds emerge, put the lid on the bottom of the
container for extra protection for your furniture. Water with a spray bottle so as
not to overwater
Some great options for Fall/Winter sowing include:
Purple coneflower (Echinacea purpurea)
Black eyed Susan (Rudbeckia)
Columbine (Aquilegia)
Bee balm (Monarda)
Coreopsis
Dianthus (Pinks)
Foxglove (Digitalis)
Globe Thistle (Echinops)
Hollyhock (Alcea)
Iris
Poppies (Papaver)
Primrose (Primula)
Shasta Daisy
Yarrow (Achillea)