AROUND THE GARDEN

Native plants are much in the news right now, for very good reasons. A key one is that they usually require less water and fertilizer than more temperamental non-natives. At right, native Joe-Pye weed and a guest.

But the next question often is, what is a native? After all, everything is native to somewhere.

Just how fussy do you want to be?Some plants we think of as native, like field daisies, came over with British colonists. There is also the question of native since when: the Dawn redwood on the right (Metasequoia glyptostroboides), for example, was known only to paleobotanists as a fossil in our area, but was eventually found alive in a remote part of China around 1946. Native or not? Tough call.

The truth is, most plants native to the northeastern states will thrive here, but only if you plant them in the conditions to which they are adapted. Being native is good from the point of view of the critters that feed on them, but it’s not the be-all and end-all of gardening. A much more important question is: how much water and sun does this plant need?

Two native Lobelias (shown below) have different requirements – the cardinal flower likes it wet, and its blue cousin tolerates drier soil.

Using the USDA Plants Database, you can generally pin down a plant to at least a region, and the site offers a huge amount of useful growing information.

Another good resource, mainly for trees, shrubs and vines, is the University of Connecticut’s Plant Database. Hundreds of species are listed by both common and botanical names, along with place of origin, hardiness zone, growing conditions, approximate height and width at maturity, as well as numerous photographs of various parts of the plant.

A good indicator of how hardy a non-native plant will be is what part of the world it is native to. Our climate is relatively similar to the eastern edge of Japan and Korea (and the northeastern part of China), so plants native to those areas frequently do well here. Coastal areas are more complicated than some others because of the contributions of wind and water currents. An astonishing botanical garden on the west coast of Scotland has palm trees growing out of doors – thanks to some quirk of the jet stream, they say.

Native plants, easy as they may be to grow, come with a built-in set of insects. Some of these are friends – the ones that pollinate. Others are a bit annoying – especially the ones that munch on leaves. On a recent visit to the Connecticut Science Center’s gardens, I spotted what looked like golden pollen on their butterfly weed (Asclepias tuberosa), a close relative of the common milkweed. Oddly, the “pollen” was on the seed pods – even more peculiar, it was moving!

A close inspection showed the golden grains were tiny aphids, of the most gorgeous brilliance. Like all aphids, however, these were laying down a sticky trail of “honeydew” – that happy euphemism for sugary excrement.

I haven’t figured out the evolutionary advantage to the aphids of resembling pollen – especially since their predators are tiny wasps, which might be looking for pollen.

The Science Center, by the way, is utterly fascinating, with four floors of well-presented, mostly interactive, scientific presentations. Exciting as it all was, I found those milkweed aphids – munching away anonymously – to be really outstanding.

The Middletown Garden Club’s Fall Plant Sale takes place at the Wadsworth Mansion Open Air Market on Sunday, August 28. A huge selection of native and non-native perennials will be offered, including new varieties of Rudbeckia and Echinacea, ornamental grasses, asters, and the large family formerly known as mums, now Dendranthema. (Full disclosure: this writer is a member of the garden club.)