Friday, October 10, 2014

Draba Growth in the Faux Barrens

I’ve cut down on the number of containers I maintain for growing native plants, while I transition to the use of open growing beds.  There are a few plants that fail to survive or just get lost when introduced into a less confining environment, so I continue to maintain their container habitat.  One of those is the tiny winter annual, Draba cuneifolia.

Winter annuals normally germinate in the fall, slowly grow basal rosettes through the winter, send up flower stalks in the spring and then wither away.  Seeds lie dormant through the summer heat and germinate when temperatures begin to cool.
I’ve noticed that the Draba cuneifolia seed left in the pot from the previous year’s plants, actually germinates in late summer.  This year, I noticed seedlings in the middle of August, during a period that was showing no signs of cooling.  Those seedlings have grown rapidly and threaten to cover the gravelly surface of my manufactured barrens with a carpet of blue-grey plants.

A dime is used to gauge the relative size of these young plants.  The dime represents a normal size for a flowering individual, although some rosettes easily grow to a size twice the diameter of the dime.  I’ve never had such a thick crop of Draba cuneifolia, so I’m anxious to see how they develop under such extreme crowding.

This is a close up view of some natural barrens in which I annually find Draba cuneifolia.  The puzzling thing is that I have never found any Draba seedlings here in the fall.  They don’t present themselves until February or early March.

I spent about an hour yesterday searching back-and-forth across the barrens for any sign of Draba seedlings.  I found none.  The reason why they develop so early in my container remains a mystery.  The container gets no special consideration during the summer.  It endures the same weather conditions and exposure to sunlight.  It may be that the concentration of seed is so much higher in the container that early developing plants are easier to see.  If my container plants don’t suffer from crowded conditions, I should have an abundance of seed produced next spring.  I may transfer a large quantity of that seed to a small section of the natural barrens to see if that results in early plants in the natural environment. 

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