Dear Master Gardener: I saw lilies at a friend’s house that were quite beautiful and fragrant. I have a few lilies, but they are not fragrant and they bloom earlier in the summer. Are there different types of lilies that grow this far north and which ones are the fragrant ones?
Answer: What does a daylily, trout lily, calla lily, blackberry lily, and lily of the valley have in common? They all have “lily” as part of their name, but none of them are true lilies. True lilies belong to the genus Lilium and grow from bulbs. There are different species of lilies and they are grouped into nine divisions. Following is a short description of the different types of lilies that are most often grown here in the Brainerd lakes area (zone 3):
Asiatic hybrids are among the earliest to bloom, the easiest to grow, and have the broadest color range of any division. There are miniature Asiatic lilies called “pixies” that typically get about 18 inches tall. They grow best in full sun.
Martagon species and hybrid lilies are tall, colorful, long-lived, and usually bloom around mid-June. They are the darlings of the shade garden and do best in a semi-shady area with filtered light. Like peonies, clumps have been known to exist for over 100 years.
Oriental lilies have large, showy flowers and a powerful, sweet fragrance. They bloom later in the season (mine are blooming now). These are the lilies your friend probably has. Most Oriental lilies are hardy to zone 4 or 5, so many people plant them in the spring and treat them as annuals. Most of the Oriental lilies I have planted over the years have not come back; however, Star Gazer and Casa Blanca have returned for years.
Longiflorum Asiatic lilies, known as LA hybrids, are a cross between a Longiflorum (Easter lily) and an Asiatic lily. They look more like an Asiatic lily than an Easter lily. LA hybrids are very popular, vigorous, and most have slightly larger flowers than the average Asiatic. They are slightly fragrant and multiply quickly.
Dear Master Gardener: I have recently planted some shrubs and would like to mulch them with some of my many pine needles. My wife, however, says that pine needles will make the soil acidic and I shouldn’t use them. Is she right? If so, what should I use?
Answer: It is a longstanding myth that pine needles acidify soil. University tests show that there is little, if any, acidifying of soil from pine needles. Pines thrive in acidic soil but do not significantly acidify it themselves. Go ahead and mulch with them -- pine needles are plentiful. Other mulch options are wood chips, bark chips, shredded wood chips, cocoa bean hulls (which emit a mild and delicious chocolate aroma), wild rice hulls, and many others. Mulch has many benefits. It conserves moisture in the root zone of plants, prevents weed growth, stabilizes soil temperatures, prevents the spread of soil-borne diseases, increases the fertility of soil as it decomposes, and gives a tidy appearance. In the winter mulch does not prevent the soil from freezing but it minimizes the heaving up of plant crowns from alternate freezing and thawing. Rock and stone mulches are attractive but are not weed-free, as many assume. They tend to compact soil and are extremely difficult to remove.
Dear Master Gardener: There is a shady area in my lawn where grass won’t grow and I would like to replace it with a ground cover of some sort. On a list of ground covers I saw wintergreen listed. Would it be a good choice for this area?
Answer: The short answer is “probably.” Hardiness is not the issue because wintergreen (Gaultheria procumbens) is hardy in USDA zone 3. It does, however, require partly to deep shade and acidic soil that is moist and rich in organic matter. It has glossy, evergreen leaves that release the wintergreen scent when crushed; small, egg-shaped, white flowers in summer; and striking, edible, red berries in the fall. It grows from rhizomes that creep along underground, sending up short 6-inch stems at intervals, slowly expanding its territory. Birds like it and it has lovely, burgundy fall color. It may not be readily available in local nurseries but it can be purchased from catalogs or — if you have it growing wild in your woods — it can be propagated from cuttings in the summer or from rooted suckers in the spring. People who like wintergreen-flavored chewing gum, toothpaste and candy are often unaware that their fresh, minty taste comes from oils from this hardy, beautiful, low-growing shrub. Native Americans used wintergreen medicinally because it has some mild analgesic and fever-reducing qualities, but most of us just enjoy its flavor.