Monday, May 6, 2013

Easy, Inexpensive Window Sill Gardening

With a minimal investment of time (1 -2 month), space (4 inches wide), and money ($25), beginning gardeners can enjoy rapid results by planting seeds in an indoor window sill garden.    

On my 4 inch wide window sills of two, four foot (double paned) windows that face south, I fit six plastic six- pack planters each (twelve packs total, 72 plant holes). Starting March 10 (still winter here - it snowed until May 3), I planted the seeds of a variety of herbs, flowers, and vegetables. My expectations were low because the setting wasn’t the greatest – the window doesn’t offer full sun all day (because of spruce and birch trees) and the temperature inside our log cabin varies from a low of 53 at night to a high of 69 during the day, and the temperatures just beyond the window were below freezing every night. 

May 3, 2013 snow fall in front of the shower house
Of the 21 plants I started indoors, below are my notes on the fastest, easiest and most robust ones that grew on my window sill from March 10 through May 5 (today), during one of the coldest Aprils in Alaskan history. Since they did so well for me, I hope the results inspire readers to try seedlings on window sills of their homes, classrooms, or perhaps, offices or hospital rooms.    



Cosmos is an easy annual flower to start indoors or outdoors in Alaska.  It looks like a daisy, but with a broader range of colors.  It has lacy foliage, and can grow up to three feet tall.    Started indoors on March 10, cosmos was the star of my window sill garden.  Every seed germinated within a few days, faster than any other.  The plants grew rapidly, too, to 4-12 inches tall with lots of leaves within six weeks.   Today, two plants are forming the bud of a future flower.   The seeds can be planted directly in the garden too (after frost), and will bloom early summer to frost.  Best of all, cosmos prefers to be neglected.  Too much care once they are established can inhibit the flowers!  What’s not to like?

Nasturtium - 6 weeks

Nasturtiums are a wonderful flower for Alaska (and just about anywhere else, too).  They come in climbing, trailing, and bushy varieties and have a rather tropical look to the flowers, which bloom for about ten weeks.  They are recommended companion plants for certain vegetables, like cabbage.  Every part is edible, too!  These are particularly good seeds for children because they are large enough to handle, about the size of a green pea.   Nasturtiums require three special treatments to start but after that, they are among the easiest to grow.  (1)  The seed can suffer freeze damage, so my Alaska supplier no longer ships them in winter.  Rats.  How will I start them indoors next year?  (2) The seed pods are hard, so to speed up germination, SOAK them overnight before planting.  (3) Then, they require DARKNESS to germinate.  I simply put the first six pack of seeds beneath a table and the second one I tented under tin foil.  Three seeds sprouted and yielded healthy, handsome plants.  By six weeks, all of these had four attractive leaves and were becoming root bound in the little seed pack so I transplanted them into a hanging pot.  A week later, each was a healthy 6-8 inches long, leaning toward the sun.  The other three seeds were still hard, so I soaked them again and replanted them the next day, but they still had not sprouted 8 days later.  Maybe duds.  So I soaked another set.  We’ll see.  I would like several more.  After danger of frost, I’ll hang the pot outside for a profusion of 6 foot trailing orange and yellow flowers.  How lovely. 


Many herb plants have teeny, tiny seeds which may be better handled by adults than children.  They are so small that some “hijacked” a ride on my fingers to another pot, and popped up where I didn’t expect them!

Basil seeds will sprout faster if you soak the seeds first, on a damp paper towel or napkin for 6-8 hours.  With this treatment, of all the herbs, the basil plants sprouted fastest, within a week.  Within six weeks, I had several small plants with 4-6 glossy leaves each and that delicious scent.  Note:  don’t let this plant dry out and don’t let it get cold.  In my part of Alaska, it will be a greenhouse plant.  

Cilantro - 4 weeks
All of the cilantro planted on 3/28 sprouted and grew rapidly.  The familiar looking true leaves started to appear three weeks later.  Before that, the sprouts looked like grass and I wasn’t sure I had labeled them correctly!  Nearly a month later, on 4/24, some of the plants were becoming root bound. (Cilantro has a long tap root), so I transplanted them to deeper pots.  Cilantro is cool tolerant.  When frost danger is past (mid-May), the pot will remain outside on the porch. 

Anise hyssop seeds require a cold start.  So I just put the packet of seeds outside for several days (temperatures 0-+20).  All sprouted and put out many side leaves quickly.  These attractive plants will be transplanted into the garden, where they will grow to 2-4 feet tall, with leaves that taste like licorice, topped by a lovely thin, spike of purple/blue flowers (other hyssop variants range from yellow to red).  They make a good border plant in full sun.   The early leaves looked much rounder and more pinked (as if trimmed with pinking shears) than the long, serrated leaves I expected.  I didn’t recognize the seedlings except by the taste of the leaves.

I love chives and planted garlic chives along my window sill. The seeds took longer than a week to sprout but once emerged, the very skinny seedlings (like needles) reached more than 2 inches tall within a week and continued their fast pace to date. Chives are easy care perennials (and easy to divide, too) with very attractive flower “balls” on stalks above the thin, grass like leaves (both flowers and leaves are edible).  Those in my garden were wild ones that I transplanted, and their pink flowers are often the first to bloom in the spring.   Intermixed with other flowers, their scent can deter voles and hares (supposedly) but not my free ranging chickens, (which have no sense of smell).  In the window sill garden, I sowed garlic chives.   These will have a large white flower “ball” on a tall stalk that will bloom later in the summer than the wild ones.        


Leaf lettuce 5 weeks

Leaf lettuce planted on 3/10 we started to harvest in mid-April.  The leaves didn’t really look like traditional wavy leaves of lettuce until after the first cuttings prompted additional growth.   To be frank, the type I planted didn’t have much flavor or even much texture, but it was satisfying to eat something fresh so quickly, and my meat rabbits love it.

Broccoli and cucumber planted on 4/17 germinated much more rapidly than I expected, within three days!  Cabbage followed a day later.  How fun is that!  Each is an interesting looking sprout, easy to distinguish from one another.  Cucumber seeds are a good choice for children because they are large enough to see and recognizable as those seen in the mature vegetable.  The cucumber will be a greenhouse plant and the other two can tolerate a light frost and will go in the garden early.     


Carrot:  Carrot seeds are so tiny that I didn’t try to parse them out among the six packs but just started in a deep pot.  You just sprinkle them on top of soil and then spritz water over them until they sprout.  This took about a week.  All of a sudden, the pot looked like it had a thin field of grass.  Once the sprouts get to be 2” tall, you thin them, eating the intervening sprouts (not much flavor or texture at that point). 


1: Supplies:

The soil in which I planted the seeds was a combination of Miracle Gro and Perlite.   Packet of seeds cost between $1-2.50, depending on the plant.    I bought my seeds from Denali Seed Company in Anchorage ( and Pine Tree Seeds (in VT).  

2: Light:

I relied solely on natural light.  My southern windows do not provide full sun exposure all day because of several tall birch and spruce trees which provide partial shade at various times of day.   Over the months of March and April, we had one uninterrupted 10 days of sunshine, but also three 3-5 days each of snow fall (including April 30, May 1, and May 2) and multiple days of overcast but bright days.

3: Temperature

My home is a bush cabin that is heated by a woodstove.  Interior temperatures are variable, reaching lows of 53 degrees at night and an occasional high of 69 during the day. If your temperatures fall in a narrower range, I imagine that your results may be even better than mine.


Helpful hints

1:  Every single seed/sprout performed best when I tented it loosely under plastic wrap spritzed with water (on the underside) to provide a more humid environment for the plant than the ambient dryness of the cabin.  (I tented some and not others to test this out)

2:   The single greatest cause of potted plant death is overwatering.  Recommendation:  use a spray  bottle to keep the soil moist before the seed emerges, and then for the little sprout.  Don’t water deeply until a bit later in plant development.  Stick your finger in the soil down to your second knuckle to assess moistness   

3:  For beginners, the most satisfying seeds are those that sprout fastest, so read the labels of plant packets for your region.   Although some of my seeds never grew at all, most sprouted at or earlier than the seed label said. The fastest sprouters for me were cosmos, broccoli, cucumber, and cabbage.   The fastest growers were cosmos  (8-12” in six weeks), garlic chives, nasturtium (up to 8 inches in 4 weeks) and anise hyssop plants which had as many as ten leaves on small, attractive plants within 4 weeks.


4.  Large seeds are easier to for children to handle.  Among my list, moonflower, nasturtium and cucumber seeds are the biggest (but only one of six moonflower seeds sprouted for me). 

5:  Started from seed, you may not recognize the young plants at first, as the initial leaves (which are really part of the seed pod) don’t look like the “true” leaves you see in more mature, store bought plants.  So LABEL them with popsicle sticks or something. 

6: Denali Seed Company offers wonderfully informative growing hints on many plants well suited to Alaska on its website,   Sites with good planting information for all regions include  eHow, About, and Dave's Garden.  The very best resources of all tend to be Community Extension papers available, for example, from University of Fairbanks (or other state colleges)  Just Google the plant name + Alaska or + UAF.


From this window sill experiment, I learned how easy it is to grow seedlings indoors, even in less than optimal sunshine and temperature control. I experimented with a variety of requirements, including darkness to germinate, cold starts, soaking.  Overall, a MUCH higher percentage of seeds sprouted than I expected, and several of the plants grew faster or became root bound faster than I anticipated.   It was very satisfying!  

Since this spring is exceptionally cool and snowy,  I am unable to transplant them outdoors or in the greenhouse as early as I expected, so I wish I had more medium sized pots.  Overall, I thoroughly recommend window sill gardening for even the smallest home or classroom window.  Even if you never transplant them elsewhere, the ease of sprouting is low key, low cost entertainment.  Just spritz them twice a day!  Enjoy. 


  1. Loved your blog post on seeds. I grew some tomato plants from seed this winter. Thought I'd get them in the ground early, but we had snow on May 6 here in Kansas City so it'll be just about Mother's Day before I get them planted.

    Don, Kansas City

  2. I could almost taste the hothouse tomatoes with basil that you plan to grow, served with Basalmic vinegar, oil and maybe some fresh mozzarella (you probably know you can freeze it then use it as fresh when thawed.)
    Though I would miss my children and grandchildren I would welcome some solitude but not as much as you get! - Sherry, Houston, TX

  3. Thank you for sharing your thoughts. I truly appreciate your efforts and I
    am waiting for your next post thank you once again.