Milkweed in the Annapolis Valley


Milkweed is the larval food of the Monarch butterfly which is endangered in Nova Scotia. It woud be of valuable to know where patches of it are located to inspect during the breeding season for larva and eggs. These early stages of the Monarch can then be protected from predators and reared to increase the butterfly population. Two species of milkweed are growing in Nova Scotia.  Swamp milkweed (asclepias incarnata) tends to be found in wetter environments and Common milkweed (Asclepias syriaca) grows well in the light soils of the Annapolis Valley and is known to be growing in several places. The Common milkweed is invasive because it spread by a robust root system as well as its airborn seeds. Large patches of it can occur in abandoned unused fields but most patches are small with less than 50 plants.

Below is a Google map of  known locations of Common Milkweed.(Nov 2015) known by L.Bogan. The icon (Sunflower) marks locations on the map where the milkweed has been found. Most of the sites are near Cambridge because that is near where he  lives. More exists but is still to b located.  Please help in surveying the Annapolis Valley to locate more sites.  email:

Note: Click on the icon for a brief description.  Zoom in to locate the site more accurately on the map.If your browser doesn't show, herer is the  map on Google Maps

Here is a note from Klaus Jensen who lives north of Coldbrook on Brooklyn Street about Common Milkweed:
"The first recorded occurrence was in 1929 (I think) near the Avonport  train station. That year some national botanical organization took a train trip from Halifax to do some botanizing in the Valley and the finding was recorded in The Canadian Field Naturalist.  In the late ‘80’s or early ‘90’s the Nova Scotia Department of Agriculture’s weed inspectors conducted a milkweed survey of Kings County, and as I recall,  some 347 locations were found.  The distribution of milkweed at that time was clearly associated with the east/west railroad line and was likely introduced in grain shipments.  At that time, milkweed was on the noxious weed list and and there was considerable effort to keep it in check by spraying it.  Herbicides were never successful in eradicating it from any location although milkweed could be suppressed.  This program ended at least 15 years ago.  Since then stands of milkweed have greatly increased and new stands are popping up in many places."

In the botianical book "Flora of Nova Scotia" by Roland and Smith (1969 N.S. Museum)

"Ascleplias syriaca (Common Milkweed)

          Sparingly introduced as a weed in light soil; at scattered places in the Annapolis Valley; at Le Breau's Creek in Hants Co.; and near Mabou in CB; presumabley being introduced also elsewhere. Scattered throughout the Maritime Provinces. July"

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