2018

City of trees … and bees!

By August 17, 2018January 19th, 2020No Comments

It’s not hard to imagine that being stuck literally in one place permanently creates some reproductive difficulties. Lots of plants overcome this problem by simply producing clones so that the only genetic material they need is their own.

Daffodil bulbs and gladiolus corms form offsets; sword ferns send out underground stems that develop new plants along the way; poplars send up new plants from their roots; airplane plants produce new plantlets at the end of aerial stems which bend down and root.

These methods allow for the species to expand its territory but, since the new plants all have the same gene combinations as the parent, there is pretty much no diversity. This may be desirable if you are a gardener wanting all the plants in an area to look and behave the same, but may not be good if you are a plant in the wild at the mercy of changing conditions.

In that case, mixing your genes with those of a plant with different heritage will result in offspring with a variety of characteristics and increase the chances that some of them will be better adapted to any environmental changes that may occur. (I will note, though, that there is an acres-wide patch of clonal creosote in the Mojave that is over 9,000 years old, so if conditions remain stable, cloning works just fine).

Most plants, even those that routinely clone themselves, produce eggs and sperm that result in a variety of offspring, just like in human families. Unlike us, however, many plants can self-fertilize if need be. This produces some new combinations but not as many as if their genes merged with those of a different individual, so getting your gametes out there is still generally preferred.

How to get eggs and sperm together is a problem faced by both plants and animals. Barnacles and mussels fling their gametes by the thousands into the water; some meet and produce larvae to swim away and settle in new locations.

Many plants, such as the grasses and conifers, follow a somewhat similar method, releasing masses of pollen (much to the dismay of those who have allergies) into the air to be wafted to waiting eggs on other members of the species. This is rather hit or miss, and requires a goodly amount of wasted energy since most of the pollen misses its target.

And now, finally, to the bees! Getting an animal to carry pollen around to other members of the same species is a lot more efficient than relying on the breeze, and bats, birds (in our area, only hummingbirds), and various insects such as bees, flies or moths, may oblige. Some of these visit to collect the protein- and fat-rich pollen; others are attracted by energy-rich, sugary nectar.

In both cases, some pollen sticks to fur, feathers, or hairs and is brushed off on succeeding flowers. Honeybees, which are not native but have naturalized here, have a habit of visiting one type of flower at a time, and this and their large populations make them very efficient movers of pollen within a species.

All our common vegetables (except for wind-pollinated corn) benefit from bees, and not only from honeybees. Tomatoes receive visits from heavy bumblebees that “buzz pollinate” the flowers. And we have lots of other native bees that pitch in too; California has over 1500 species!

Some bumbles live in small colonies in tree cavities, or abandoned bird nests, but most of our natives are solitary bees: they may create nests in the ground, like the digger bees; in soft wood like the carpenter bees; or in hollow, dead plant stems and small cavities, like mason, orchard, and leafcutter bees.

The number of bees in Southern California has been decreasing, so it’s really important that we take steps to provide food and nesting sites for all the bees around us.

We can leave some dead wood, some dead stems, and some unplanted, unwatered ground in our gardens for them to use, or buy or build nests for them. We can choose plants that flower successively throughout the year and include some native plants so the bees always have some food, and avoid using pesticides because they kill the bees too.

Set aside some time to go out and watch your plants to see which native bees are visiting. Natives rarely, if ever, sting. Even honeybees only sting if they feel seriously threatened so never swat at one if it comes around. Just act calmly and they will ignore you; after all, you don’t have any pollen or nectar to offer.

I just deadheaded an African blue basil full of bees without any problem. However, it’s a good idea not to smell like a flower if you do this! And of course, if you are allergic to bee stings, enjoy the bees from afar and always keep an EpiPen nearby when gardening!

Let’s do our best for the bees—they do a lot for us! The Garden Club website (claremontgardenclub.org) has links to more information about our bees, and a list of the talks scheduled for our upcoming meetings which are free and open to everyone.

On September 12, Lili Singer will talk about how to combine native plants with vegetable gardening — we’d love to have you join us!

The Claremont Garden Club is a working group of Sustainable Claremont (susustainableclaremont.org).

Demystifying Sustainability is an initiative of Sustainable Claremont (susustainableclaremont.org).

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