Category Archives: Featured

An Aster by Another Name

raydon

Symphyotrichum ‘Raydon’s Favorite’ with Dendranthema ‘Sheffield Apricot’

Are you confused? We were. Asters were one of the easy botanical names to remember, since the common name was exactly the same as the Latin name, until maybe a decade ago.  We started to notice that certain wholesale sources were listing many common fall aster species as Symphyotrichum (pronounced sim-fy-oh-TRY-kum). This brought up questions. Will this name take hold with the gardening public? Should we reclassify the plants we were calling Aster? And which asters were considered in the genus Symphyotrichum? Would our customers know to look under this new genus name when seeking the fall blooming asters?

Upon research we discovered that once botanists began comparing the DNA of Eurasian Asters with North American species, they found that the asters native to North America were more closely related to other native genera, especially Boltonia, Solidago and Erigeron. To be brief, the North American Asters included in the Symphyotrichum group are the species: cordifolius, dumosus, laevis, lateriflorum, novae-angliae, novi-belgii oblongifolius. Two New World Asters, divaricatus and macrophyllus are now considered to be Eurybia species.

Some of the Eurasian species have been reclassified into the genera Crinitaria, Galatella and Bellidiastrum, (few of which are commercially available here in the US) while others still remain in the genus Aster, including Aster amellus, ageratoides and tartaricus. The question remains as to what would be the correct nomenclature for Aster hybrids, such as the new selection Aster x ‘Blue Autumn’, recently introduced in the US by European breeders as a cultivar of Aster laevis, incorrectly we might add. We’ll keep you posted when we know for sure.

Time to Plant Fall Containers

Pennisetum with Heuchera ‘Caramel’, Cuphea and Calibrachoa

One of the pleasures of container gardening is that you can create fresh arrangements to complement each season?s landscape. The colors of Fall Chrysanthemums have been selected for just this effect, but isn?t it dull to limit yourself to just a single plant? Consider the wide selection of cool season “annuals” that are at their prime in September and October, offering at least 6-8 weeks of color. There are ornamental peppers, salvias, grasses, million bells, abutilons and cigar plants, just to name a few. Don’t forget the perennials with outstanding foliage, like Heuchera ‘Caramel’ and Autumn Fern (Dryopteris erythrosora)  which add contrast and can later be transplanted into the garden for next year?s display. And then there are shrubs with fall interest, such as Hydrangea paniculata ‘Little Lime’ (aging  blossoms), Cornus ‘Arctic Sun’ , and Ilex verticillata (Winterberry), which will add height and weight to bigger pots. Here are two more tips for pulling it all together.

First, remember to select a variety of bold and fine textures. The bold punch of a large leaved Heuchera, or Ornamental Cabbage adds much needed weight and contrast. This is the season of ripening fruit, so take advantage of the ever widening selection of Ornamental Peppers or consider shrubs with a nice berry set, such as Viburnum or Winterberry. Grasses add height and movement, and you can always use hardy grasses besides the more showy annual Pennisetum.

Second point: The growing season is slowing down here in the northeast, so start with larger plants and/or use more plants to fill up the container right away. There is not a lot of time now for plants to put on added growth. Think of assembling your container as you would a flower arrangement, except that this composition will last for weeks as opposed to just a few days.

Tricyrtis formosana ‘Gates of Heaven’

Just the common name, Toad Lily, sparks curiosity and invites close inspection. The delicate blossoms of this attractive cultivar of Tricyrtis formosana resemble small orchids and have distinctive spotting on the blue-violet petals. Flowering interest begins in early August, but the golden yellow foliage adds color early in the season. Plants are stoloniferous, forming small clumps 12″ high, making it suitable for the front of a border. Small Hosta such as ‘Wogon Gold’ and Japanese Forest Grass Hakonachloa macra make excellent companions.

Grow Toad Lilies in a soil that stays uniformly moist, yet well drained. The foliage tips will brown if the soil becomes too dry, and although not lethal, will make the plants less attractive. Tricyrtis ‘Gates of Heaven’are unappetizing to deer, and are hardy through zone 5-9. 

What’s Eating My Plants? I

Tobacco Hornworm

Don’t you just hate this? One day you have a perfectly healthy plant, and the next time you look, the leaves are riddled with holes, or completely gone! Just 2 days ago, I photographed a lovely stand of Nicotiana mutabilis (Flowering Tobacco). As I walked by this morning, I was stunned by totally denuded stalks. On closer inspection, there was a 4″ Tobacco Hornworm chomping away, leaving behind a trail of excrement. Not a pretty picture now.

The Tobacco Hornworm Manduca sexta is the caterpillar of a type of Sphinx Moth or Hawk Moth. It differs from the Tomato Hornworm by having a reddish instead of a black “horn”, and you can also tell the difference by its lateral markings. The Tobacco Hornworm has seven diagonal lines, while the Tomato Hornworm has eight v-shaped markings.

The adult female Sphinx Moth deposits her translucent green eggs on the undersides of leaves of plants in the Solanacea family, especially Nicotiana (Tobacco), and take 2-4 days to hatch. During their larval stage, these Hornworms feed on the foliage, flowers and fruit. They can ingest the toxin Nicotine without ill effects, and their voracious appetites allow them to strip even large plants overnight. Their green bodies camouflage well with the plants they feed on.

Control this pest by handpicking the caterpillars. If you have too large a crop for handpicking, you can use a product like Dipel (Bacillus thuringiensis) or Monterey Garden Spray (Spinosad) on the young larvae. Be on the lookout for hornworms with little white “pills” attached. These white attachments are the eggs of the parasitic Braconid Wasp, which feed on and weaken/kill the unsuspecting hornworm. This biological control is a good example of nature keeping everything in balance.

Container Combo for Dry Shade

Begonia, Pilea and Tahitian Bridal Veil

Again, it is so much about the foliage. The angel wing leaves of Begonia ‘Sinbad’ are really a soft celadon green veined in rose, but have a silvery cast. On close inspection, the silvery effect is due to the pebbly texture formed by the tiny raised white leaf segments. Simple, sweet pink flowers dangle from the leaf axils.  For filler, the tiny white variegated foliage of little Pilea, commonly called artillery fern, creates a frothy effect beneath the bolder leaves of ‘Sinbad’ and the casual abandon of Gibasis geniculata , also known as Tahitian Bridal Veil, with its two tone green/purple foliage and white baby?s breath blossoms finish off the combination.

Culturally, use a well drained potting soil, amended with Osmocote. Begonias do not want to live in soggy soil, so monitor watering by allowing the soil to dry out a bit. This ensemble would enjoy morning or filtered light, and would be a suitable arrangement for a covered porch, where the minimal watering needs can be monitored.

Container Combinations I

Pink/Wine/Silver Combo

A classic combination for a sunny spot. We’ve combined our favorite Pelargonium sidoides with a new heat tolerant pale pink Marguerite, Argyranthemum ‘Pink Reflection’, silvery Centaurea gymnocarpa ‘Colchester White’ and Dichondra ‘Silver Falls’ and a compact selection of Gaura ‘Belize, with wine tinted foliage and wine/pink blossoms that dance on 18-24″ stems all summer.