“The Great Seed Experiment” is off to a vigorous start! Hundreds of patrons have picked up seeds for their home gardens, as well as helpful factsheets and seed journals to record their observations. This week, the library received its first photos and “Sprouting Reports” from gardeners. Spring peas are already germinating.
If you started tomato seeds indoors during the past month, you will soon be rewarded with seedlings. My “Black Krim” seedlings, planted on April 18, look like this:
It won’t be long before I transplant them into bigger peat pots. [Note: If you use a plastic egg carton as a starter tray, be sure to create drainage holes.]
We still have seeds available – green beans, cantaloupe, corn, and lots of watermelon and pumpkin seeds. Thus, this week we are announcing an offshoot (bad pun) of “The Great Seed Experiment”: “The Giant Pumpkin and Watermelon Contest.”
1) Your seeds must come from the Ames Free Library’s giveaway. Save your seed packet
2) Take at least one photograph of your mature plant.
3) Bring your watermelon to the library to be weighed and photographed by September 15. Pumpkins must be brought by October 15. Bring the photo of your mature plant and your seed packet to identify its variety. We will use these items for a library display. Winners of each category will receive a garden-related prize.
Pumpkin and watermelon seeds should be planted outdoors two weeks after the last frost which occurs in Easton, on average, between May 21 - 31. Alternatively, they may be started indoors 20 days before the last frost, then transplanted outside when the danger has passed. Planting season is between late May and late June. Be sure to read the directions for your variety on the back of the seed packet.
Whatever seeds you choose, submit a Sprouting Report once they germinate. That data will help us determine which seeds best survived dormancy. Send photos to firstname.lastname@example.org. Good luck!
You may recall from the introduction to “The Great Seed Experiment” that the library acquired its seed collection in 2020. That means that these seeds have lain dormant for two years. Will they still germinate? How long can seeds remain dormant and viable? The less-than-satisfying answer is “It depends” – on both the species and the storage conditions.
Some plant species produce seeds that will die if they freeze or dry out. Their seeds are deemed “recalcitrant” because they are more difficult for people to store and grow. Botanist William Cullina suggests that a better term for these seeds might be “hydrophilic.” According to the Nursery Manual for Native Plants: A Guide for Tribal Nurseries, “recalcitrant seeds retain viability for only a few days, weeks, or months and, generally, for not more than 1 year.” This group includes water-loving willows and wild rice and nut-bearing trees like white oaks. It also includes many early-blooming flowers of moist forests, what I know as spring ephemerals, plants whose seeds mature and are dispersed in constantly moist conditions. Woodland beauties such as bloodroot, trillium, and wild ginger are considered difficult to propagate because their seeds require special treatment.
Bloodroot, Tyringham Cobble
Other plant species, including many of our food crops, produce seeds that can tolerate desiccation and low temperatures. These “orthodox” seeds retain viability for longer periods, greater than a year and sometimes much longer. Indeed, they are best stored in cool, dry conditions. The Ames Free Library’s seed collection was kept dry but at room temperature. We’ll soon see if warmth impacted their capacity to germinate and thrive. Many gardening websites estimate the viability periods of vegetable seeds. This chart from the Chicago Botanic Garden is exceptionally clear and easy to read.
People have long wondered about seed viability and what conditions trigger germination. Indeed, the library’s gardening program was inspired by a much earlier inquiry, the Beal seed viability experiment at Michigan State University. “One of the world’s longest running science experiments” began in 1879 when botanist William James Beal filled 20 bottles with sand and seeds . . . and buried them on campus.
Each bottle contained 50 seeds of 21 different species, mostly those of weedy plants that plagued farmers. Every five years, caretakers from the University’s staff would dig up a bottle, plant its seeds, and record the results. Over time, the intervals expanded to ten, then twenty years, as younger staff took up the gauntlet, and the experiment’s mystique grew. After 142 years, one species, the moth mullein, is still sprouting! In 2021, The New York Times described the most recent excavation and the project’s relevance to today’s conservation challenges.
Matt Lavin from Bozeman, Montana, USA, CC BY-SA 2.0
If the moth mullein is persistent, the longevity prize goes to the Judean date palm. In 2008, scientists planted a 2000 year old date palm seed that had been excavated at Masada, the ancient fortress in southern Israel. It grew! And now, four male and two female trees are growing from other date palm seeds discovered at ancient archaeological sites. Learn the details of this remarkable story in “After 2,000 Years, These Seeds Have Finally Sprouted,” a short article in The Atlantic. After a mere two years, our veggies should do just fine.