All in the Family

A sulphur butterfly visits Joe-Pye Weed.

Like all living things, plants are organized into natural units or families based on their genetic similarities. Understanding what family your favorite garden plant is a member of can help you better care and plan for it. For a botanist, looking at the flower (the reproductive structure) is usually all that’s needed to identify a plant's family. And although some vegetative (nonflower) structures like leaves and stems are helpful guides — “sedges have edges,” for example, and mints have square stems — there are usually exceptions to these adages.

Two extremely important plant families with many representatives in the flower garden are the mints or Lamiaceae and the daisy or Asteraceae. Both of these families are large, with many genera and worldwide distribution. Here on the East End, my garden includes many representatives of these families. The species I describe here are all easy to grow and all are resistant to deer browsing.

The mint family makes a major contribution to our cooking and medicinal herbs. They are highly aromatic and have distinctive, irregular flowers — often purple or pink and sometimes red. Don’t just restrict herbs to the herb garden — they are so beautiful and deer resistant that they should be planted widely. One of my favorite members of this family is rosemary (Rosmarinus officinalis). Rosemary is cultivated for its strong, pine-like aroma which you can release by just touching the leaves. If you prune a plant the aroma can sometimes be overwhelming. But who would imagine that rosemary is a close relative of basil? The plants don’t look anything alike—one is an annual, one is a perennial and woody. If you’re lucky on the East End rosemary can be overwintered for many years. But it’s the telltale small, irregular purple flower that tells you these herbs are related. Rosemary is a native of the Mediterranean region and requires full sun, excellent drainage, and poor soil. The only trick with rosemary on the East End is that we are pushing its northern limit. To grow it as a perennial, therefore, you must plant it in a sheltered spot. I wrap mine in burlap in winter, and at press time I didn't know if they survived this unusually cold one.

Another mint family member that gives great pleasure in our East End gardens and is also deer proof is culinary sage (Salvia officinalis). There are 900 species of salvia so you can really go crazy with them, but the culinary sage is now available in wonderful color varieties and variegated forms. Like its cousin rosemary, it requires full sun and well-drained soil.

Color in the autumn garden is largely thanks to the Asteraceae. This large family is home to asters, daisies, sunflowers, and many other plants. Their flower structure is highly complex. It is actually a composite of many small reduced flowers which form a head (think sunflower). A few of the many native species grow well in the garden here, and I’m a big fan of goldenrods and the genus Eupatorium. Goldenrods make up the genus Solidago and the two species I use in the garden are very different and provide nice contrast. The seaside goldenrod (Solidago sempervirens) is showy, with glossy, big green leaves and clusters of yellow flowers that are very attractive to insects. It’s in its glory on our dunes where it thrives in the harsh dry conditions. You don’t have to completely recreate a dune in your garden, but for best flowering you’ll want a nice, hot, very well-drained site. Its petite cousin the grass-leaved goldenrod (Solidago graminifolia) forms clumps and has delicate, feathery “grass-like” leaves. Like all goldenrods, it needs lots of sun but thrives in moister conditions than the seaside goldenrod.

Eupatoriums — sometimes called bonesets — are also in the Asteraceae family. Joe-Pye Weed (Eupatorium purpureum) is a great native plant to use in the garden. Give it full sun and moist soil and you’ll have a six-foot display of mauve-purple flowers, which also attract many insects. A diminutive cousin is Eupatorium hyssopifolium. In late fall its clusters of small flowers and hyssop-like leaves have a subtle off-white color and create a delicate silhouette. The best way to cultivate it is to gather seeds from a colony growing on a sunny, dry roadside, scatter them on a sandy, sunny area of your garden, and hope for the best! k

Sara Davison has been transfixed by plants since reading “The Secret Garden” as a child. She has a master's degree in botany and ecology from Rutgers University and lives in East Hampton.

Monarch butterflies, which are in decline, love seaside goldenrod among other native plants.
Bumble bees like seaside goldenrod too.