Getting a Jump on Seeds for 2012

As I was flipping through the Feb 2012 issue of Garden Gate magazine, I came across an article about winter sowing perennial seeds.  While I’ve seen this type of thing before, this time it sent me into action.  I’ve been moaning about why some seeds I’ve tried just won’t germinate well, if at all.  The method described in this article by Michelle Mero Riedel, can also be found at the ‘My Northern GardenBlog', and at the Winter Sown Seeds website. So today I grabbed the two containers I had on hand to give it a try.

1. Cut container, leaving a hinge
2. Make plenty of drain holes

3. Add seed starting mix

In short, it involves cutting 90% of the way across the top of a 1 gal plastic milk carton (or similar) cut, to create a hinged lid.  After making some drain holes in the bottom it is loaded with pre-moistened seed starting mix.  The seeds are sown at their recommended depth and the top is taped back in place.  

4.  Sink the containers in soil 
outside in a sunny location

Next the carton is put outside in a sunny exposed location and sunken into the soil to simulate the actual soil conditions.  In this way the seeds will experience actual winter conditions, but be protected from animals.  The cover creates a mini-greenhouse for protection after germination and the contained soil-less mix will be easy to break-up for transplanting after the plants grow up a bit.  It is important not to put the cap back on the jugs, otherwise the seeds will cook.

The first seeds that I am trying are one’s that did not germinate for me last time: Butterfly Weed (Asclepias tuberosa) and Rosey Sedge (Carex rosea).  As I get more containers I will also try this with the difficult Fernleaf False Foxglove (Aureolaria pedicularia) as well as with seeds that gave a lower % germination last season: Woodland Sunflower (Helianthus divaricatus), Flowering Spurge (Euphorbia corolorata), and Crowned Beggarsticks (Bidens coronata).

One trick I did differently from the article was to use a drill fitted with a brad point bit to drill very neat holes in the plastic, rather than using an awl or screwdriver.    We’ll see next spring how this method compares my usual method of cold stratification in the refrigerator.  So far this ‘winter sowing’ method has been pretty easy, plus it doesn’t take up space in the frig and I won’t need to use the grow lights for two months this spring.  Also by winter sowing early, I won’t be digging into frozen soil to sink in the containers.

"The Wild Garden"

A new edition of William Robinson’s 1870’s classic The Wild Garden has been published recently by Timber Press with additional material from Rick Darke. I was reminded of this by an essay by Darke appearing in the Jan/Feb issue of the American Gardener  entiled "What is Wild."  (Check out the link to the essay to see what I'm talking about.)  As I read this article I was immediately impressed at how well it captured my feelings on how I  like to design a residential garden—how to wed wildness and civilization.

 Robinson, a botanist and master gardener of 19th century Great Britain, wrote The Wild Garden in response to the contrived nature of the Victorian style garden. He was looking for a more natural, spontaneous, and lower maintenance way of gardening. The Wild Garden is not a manual on creating a wilderness, but rather a way of bringing nature and natural processes closer to the human environment. The key to this approach is to use plants that can naturalize to the existing site conditions and allowing them to grow and reproduce in a natural way to fill all the gaps or niches in the garden. Filling the ground plane with plants is naturally weed suppressive, conserves soil moisture and provides habitat for all sorts of creatures. To do this, plants need to be able to produce and disperse viable seed. Depending on the species this may require a genetically diverse ‘breeding stock’ and leaving some seed heads to mature and disperse their seeds.

In this style garden maintenance becomes more of an exercise in editing out seedlings rather than weeding and replacement of failed plants. The edited seedlings can become new additions to other areas or gifts to gardening friends.

In Robinson’s England of the mid 19th century, plants from the world over were available, including many from North America. These are reflected in the plant lists which he provided for the many different garden conditions encountered by the British gardener. His criteria for plant selection were that the plant be well adapted to an area to survive (rather than adapting the garden conditions to a few plants) and reproduce without dominating the garden (non-invasive). Early editions were focused on the use of introduced plant species while the 5th edition includes a significant chapter (60 pp) on ‘British Wildflowers and Trees.’ Thanks to ‘Google Books’ some of these early editions are available free of charge over the internet: 2nd edition; 5th edition.

This ‘wild garden’ approach is similar to that used for an entry garden I installed 3 years ago at the church I attend. This is a mixture of about half eastern US natives and half ‘exotics’. (I'm still waiting on a Leucothoe to fill the back corner.)  You can see that the ground plane is full. This garden gets no added fertilizer and very little supplemental water beyond the rain. Maintenance takes only 1-2 hours/year and mainly involves pulling out seedlings of bittersweet and euonymus from under the eaves where the birds sit. The Wild Bleeding Heart (Dicentra eximia) are spreading by seed and may be due for some ‘editing’ this year.

Seeds that I am starting this Year

I just finished ordering too many seeds for me to handle this year, but I will give them all a shot. Most of these are native annuals or biennials and many are native to Massachusetts, where I am located. I thought I would share my list with you all.

Native to Massachusetts:

Adlumia fungosa (Alleghany vine, biennial, shown above), Aureolaria pedicularia (Fernleaf yellow false foxglove, annual), Bidens coronata (Crowned beggar’s ticks, annual), Corydalis sempervirens (Rock harlequin) , Hedeoma pulegiodes (American pennyroyal, annual), Hypoxis hirsuta (Eastern yellow star grass, perennial), Polygala sanguinia (Purple milkwort, annual), Pseudognaphalium obtusifolium (Sweet everlasting, annual).

Some of these plants will be tricky to start and use. As ‘wild’ plants they are adapted to thrive in specific environments. I hope to learn more about their requirements and how well they adapt to a residential garden. For example, Aureolaria pedicularia is parasitic on oaks and possibly ericaceous species; the Corydalis, Polygala and Pseudognaphalium are found on thin or depleted soils and may not do well in the relatively enriched soils found in most gardens. I’ve had good success with the Adlumia – these are seeds from a previous year’s plants.

Native to New England:

In addition to the seeds above I am trying these that are native to other parts of New England:  Monarda punctata (spotted bee balm, biennial; photo on left taken at Mount Auburn Cemetery wildflower meadow) and Rudbeckia triloba (brown-eyed Susan, biennial).

This Rudbeckia grows more as a bush with smaller, 'softer'-looking flowers than the more common Black-eyed Susan (R. hirta).

Native to other parts of North America:
Agastache aurantiaca ‘Navaho Sunset’, photo to right (Golden hyssop, perennial), Cleome serrulata (Rocky Mountain Bee Plant, annual), Eschscholzia californica (California poppy, annual/tender perennial), Euphorbia marginata ‘Summer Icicle’ (Snow-on-the-Mountain, annual), Gallardia pulchella (Annual blanket flower, annual), Phacelia tanacetifolia (Lacy phacelia, annual), Phlox drummundii (Drummond phlox – straight species, annual), and Salvia coccinea (Texas sage, annual/tender perennial).

I got the Phlox and Gaillardia on a visit to the Johnson Wildflower Center in Austin, TX.  (Well worth a visit whenever you are in that part of the country!)  These southwestern and western native plants are more decorative and may have a place in a home garden. They would be out of place in a meadow planting in the Northeast (or anywhere outside of their native ranges).

NOW'S the Time to Buy Seed for Native Plants

While there are a few native annuals and biennials that you can buy at a nursery, to get true natives you will most likely need to start from seed. For native plants adapted to, or tolerant of, your climate direct sowing in place, in the fall, can work; although the success rate may be low.  If you’re starting the seed indoors under lights, some special treatments may be necessary to get the seeds to germinate.

Many of the seeds you purchase off-the-rack are for annuals from warm climates, generally referred to as 'tender annuals.' When sown after the danger of frost is past these seeds will germinate when the soil warms up. Unlike seeds for tender annuals, seeds for plants native to colder climates have a mechanism that inhibits germination until they have experienced a period of cold. This can be simulated indoors using a process called stratification. Generally speaking this involves mixing the seeds with some sterile, moist (not wet) material and storing in a sealed plastic bag, in a refrigerator (33-38°F) for a given number of days (anywhere from 10-90) depending on the specific plant you are working with. For this reason, NOW is the time to make some decisions and get those native seeds so that you can have them ready for germination.

Locating seed for native plants takes some work, but use of the internet has sped up this task incredibly. Searching on the plant’s botanical name, in quotes, and ‘seed’ will narrow the field. The New England Wildflower Society has a seed sale that will start up again in Jan. 2011, which offers many native plant species, some of which are biennials. I have found many annuals and biennial seeds from Prairie Moon Nursery, based in Minnesota (http://www.prairiemoon.com/), as well as other native seed suppliers.  Most suppliers provide the germination information required in their catalogs or along with the seed.  One comprehensive source for germination information for all types of plants can be found in Tom Clothier’s Seed Germination Database, http://tomclothier.hort.net/ .

Collecting seed nearby from the wild an effective way of getting seeds for plants adapted to you local conditions. But you need to have permission from the landowners or land managers before taking anything that does not belong to you. Guidelines on seed collection for native plants have been published by the New England Wildflower Society and can be found at their website, http://www.newfs.org/ . Remember, you do not want to remove seeds from plant populations that are not robust.

For those of us who are not inclined to start from seed, in my next entry I will list a few native (or nearly so) annuals that I have found at nurseries in the Boston area.