Sunday, January 6

Take a stroll down the primrose path

Primula denticulata (L) and Polyanthus primrose light up the early spring landscape.

With a name like Polyanthus primrose, gardeners should be forewarned that this is a perennial bent on propriety. I confess that I have been caught looking twice at a specimen to verify whether it is silk or 'the real thing.' Each clean-cut leaf is arrayed with flowers in such a way that it appears as a freshly picked bouquet, gathered into a perfectly proper bunch. However, primrose didn't get its name from being prim and proper. The name is derived from prima rosa, meaning 'first rose of the year.' And with some varieties blooming as early as March, it seems the name is doubly apropos.

Polyanthus primrose is merely the tip of the primula iceberg. There are more than 400 varieties of the species, ranging in height from three inches to four feet and sporting nearly every color imaginable. Indeed, when looking through this wide variety of plants, you may wonder what makes them all primroses.

Primulas are identified by a distinct basal rosette of leaves and five-petaled tubular flowers. A unique feature of the primrose flower is that it comes in two different forms: pin and thrum. The pin form has the style (female receptor) of the flower above the stamens. The thrum form has the stamens (male part) above the style. The best seed production comes from cross-pollinating the two forms. As one plant cannot produce both forms, you will always want to plant primroses in groupings of three or more to develop a healthy colony.

The bright colors of Primula x polyantha put this perennial in the same league as annuals long before the latter could survive springtime temperatures. Photo courtesy Proven Winners.

Primroses are not native to Illinois. They love a cool, moist environment, so it's no wonder that they flourish in England, where the pale yellow heads of P. vulgaris dot the countryside. They also grow in the rocky alpine landscapes of the Himalayas and in the low-lying lands of Asian monsoon territory. Illinois' dry growing season and unforgiving heat is not a great precursor to primrose success. Still, there are several varieties that are more tolerant, and with a modicum of care, can grace our landscapes as well.

Japanese primroses (Primula japonica) grow 18-36 inches high. Also known as the candelabra primrose, its flowers emerge in circles around the stem. These bright pink, white, red, magenta or purple flowers open in late spring and attract hummingbirds. P. japonica is the thirstiest of the primroses. It will not tolerate being dry, but can withstand being completely submerged underwater for brief periods.

Cowslip primrose (P. veris) bears fragrant yellow flowers in clusters on six- to 12-inch stems. This English native is very hardy and self-sows prolifically once its established.

Drumstick primrose (P. denticulata) seems to be a misguided member of the allium family. Its lavender, mauve or white flowers are borne in a round cluster 15 inches high, very much like the popular alliums.

Japanese woodland primrose (P. sieboldii) extends the primrose season into late spring and early summer. Bearing lacy petals, Primula sieboldii blooms in whorls of purple, pink and white. The plant copes with the heat by going dormant -- much like Dicentra spectabilis -- in the summer. It makes a good companion for hostas and its 12-inch stems make it a wonderful cut flower.

Primula x polyantha is a hybridizer's field of dreams. This perennial offers the bright colors associated with annuals long before they're available. In fact, one of the only drawbacks of these vivid flowers is their inability to 'look natural.' With startlingly bright colors, these short little perennials (usually 10-inches high or less) light up shady corners in the spring. Tuck them under foundation shrubs for an early blast of color. Plant them en masse under deciduous trees, where they can alternately enjoy the spring sunshine and find shelter from our scorching summers. Good companions include the bulb Leucojum aestivum (spring snowflake) and the perennial Dicentra spectabilis (bleeding heart).

To care for primulas, one thing is absolutely essential: consistent moisture. Primroses may very well forgive you for growing them in alkaline soil (they prefer some acidity), but they will not compromise on their moisture. They love semi-shaded areas near ponds, streams and even downspouts. Connoisseurs sometimes build special troughs to maintain a boggy haven. Primroses do prefer a rich, humus soil and will grow better in beds that has been amended with leaf mold, compost or cow manure. This organic matter helps to hold in the all-important moisture. Mulching the plants with more organic matter, such as chopped leaves, also helps to prevent evaporation and to provide some protection from temperature extremes.

Most primroses will expand their presence through self-sowing. However, if you'd like to propagate them yourself, you can collect the dust-like seeds in summer or early fall, as the heads ripen. Sow them in starter mix in a cold frame, or in another protected location outside. Primula seeds need to experience the cold to germinate successfully. The seeds will germinate in the spring. Once they've developed their true leaves, they can be moved to their permanent location. Don't forget to maintain consistent moisture throughout this process. The plants will flower cautiously the following year, but it will take another growing season for them to bloom with abandon. Primulas can be divided, after they have flowered, by teasing the separate crowns apart. Most varieties need to be divided every three to four years, so this is another excuse for spreading the primrose magic around.

Mollie Uftring developed a green thumb as a teenager working in the perennial beds at Hornbaker Gardens in Princeton, Illinois. After graduating from the University of Illinois with a degree in ornamental horticulture, she worked as a landscape designer in Ohio before returning to Illinois.