Pollinator Garden

The Pollinator garden is one of our biggest programs at The Gardens at Lake Merritt

While there are many beautiful, more formal themed gardens ringing the garden space, the center of the garden holds a big area for a wild and crazy pollinator habitat garden. Pollinators – bees, butterflies, and other beneficial insects – are in decline and threatened because their habitats are being destroyed by widespread weed spraying and urban sprawl.

Our park director Tora Rocha founded The Pollinator Posse a few years back to draw more pollinating insects to the garden. The Posse has ridden to new heights with local and national attention, including a huge display at the 2015 San Francisco Flower and Garden Show.

With a nod to the alarming declines in the population of the Monarch butterfly, we plant native and a little tropical milkweed in our gardens, as habitat for the butterflies, their eggs and their caterpillars. Other butterfly species are cultivated as well, and of course, our famous Bee Hotel, modeled on a Bee Hotel in the Place des Jardins in Paris. http://www.arkinspace.com/2012/06/welcome-to-bee-hotel.html Built by Oakland carpenters in the Department of Public Works, it is a draw for young and old and adds to our magnetism for many pollinator species.

The Bee Hotel shelters drilled openings of many sizes to provide nesting space for various species of native bees and other insects.

Here’s the thing:

growing habitat gardens are inherently messy! Seedlings are underfoot, so conventional weeding and mulching have to be handled with special care. There might be larvae of something spectacular lurking under any dead leaf. The caterpillars chomp through the milkweed leaves leaving gaping holes – in a normal garden this would be an unsightly cause for alarm, but for us it’s a sign of success! If they eat here, they lay their eggs here and hatch here.

The first year of the Pollinator Posse project we had just a few butterflies – six by our count. Last year there were 306 and in 2014-15, thanks to our fostering program, we have released over 600 butterflies into the garden.

And fostering caterpillars – what is that anyway? We find lots of Monarch caterpillars in the garden. To protect them from their many predators, we gather them, and volunteers take them home in mesh cages, feed them milkweed for a few weeks till their go into chrysalis, then wait patiently for the exciting emersion when the butterflies “eclose” from the chrysalis.

Monarchs have a storybook migration, metamorphosing their way from Mexico and California to British Columbia each year, over four generations of butterflies that magically keeps knowing where to go. The Western Migration of the Monarchs overwinters in coastal California, while the Eastern Migration goes to Mexico.


A huge storm in Mexico a few years back wiped out 500 million Monarchs. The the species is not yet officially endangered, but being considered for that status. The numbers are 95 percent lower than the high point of 1.05 billion in the mid-1990s. Entomologists blame the plummeting population on logging in Mexico, climate change and the mass destruction of the milkweed plant along its migration route in the United States. We help as much as we can in our small corner of the garden world. Watch for workshops in the garden, teaching families how to participate in this early science learning for kids.

“Some 56.5 million monarchs are gathered in Mexico for the 2014-5 winter after their amazing trek across the United States, scientists with World Wildlife Fund Mexico estimate. That’s a good deal more butterflies than last winter, when 34 million were counted in Mexico’s Sierra Madre, the lowest number recorded since 1993 when entomologists began keeping records.

“A much smaller population winters in California, which saw an estimated 235,000 monarchs, a 50 percent decline compared to the 18-year average, according to scientists. The monarchs, which gather for the winter in more than 200 groves along the California coast, declined 90 percent between 1997 and 2009.”