PRODUCTION TIPS Researchers from the Floriculture Program at Michigan State University (MSU) share research-based information on some of the top perennial performers from the past few years. PERENNIALS Production Tips For Top Performers Chasmanthium latifolium

Northern sea oats is a great ornamental grass for native, shade and naturalized gardens.

by SONALI PADHYE and CATHY WHITMAN A close but distinct relative, southern also been used successfully in urban sea oats (Uniola paniculata) is distrib- landscapes and charming containers. URING a brisk, wintry walk uted throughout the sand dunes of the Chasmanthium is of particular interest in a Michigan garden, one southern United States and is used in to many gardeners due to its moder- Drealizes that, of the few ele- dune restoration and erosion control ate height (2 to 5 feet), deer resistance ments of winter interest in projects. and its adaptability to shady locations. the garden, ornamental grasses stand Great for use in native gardens and Many popular ornamental grasses tall. There has been much said and naturalized are full sun plants written about the extraordinary ver- areas, chas- and become floppy satility of the landscape use of orna- manthium has in shady areas, while mental grasses. Grasses add chasmanthium thrives stature, texture, movement in part shade. As with and fall and winter interest many other ornamental to any garden. Chasmanthium grasses, chasmanthium latifolium, commonly known is fairly easy to maintain as northern sea oats, is no and adds great value to exception. With its bamboo- gardens in return for the like foliage and delicate inflo- little time invested in rescences, chasmanthium is plant care and maintenance. Its attrac- certain to interest gardeners tive inflorescences can be used in fresh (figure 1A and B). or dried form in flower arrangements. Chasmanthium latifolium is Seeds can readily germinate when native to the United States dispersed on the ground, resulting and is naturalized from in a small mass of seedlings around New Jersey to Pennsylvania the planted chasmanthium each year. in the Northeast to Texas Often, home gardeners remove seed- and northern Florida in the lings to prevent the proliferation of Southeast. Chasmanthium this grass; while in some landscapes, is hardy to USDA Zones this spread of chasmanthium is pre- 4 to 9 and is often found ferred to promote its naturalization. naturalized in shady areas Container production of chas- in forests, near rivers and in manthium is as easy as growing flood plains. Although the and maintaining it in the garden. common name, northern sea Figure 1A and B. Chasmanthium latifolium Consumers prefer buying plants in oats, suggests its proximity plants provide movement and texture to a flower, and ornamental grasses follow to water, the natural habitat summer garden, while inflorescences add suit. While some grasses may be dif- of chasmanthium is inland. color and interest to a fall and winter garden. ficult to produce and market in flower,

A Special Thanks To Our Sponsors PRODUCTION TIPS Critical Photoperiod No plants flowered when forced PERENNIALS Forcing under long-day (LD) and under a 10- or 12-hour photoperiod, short-day (SD) photoperiods promotes 90 percent of plants flowered under chasmanthium can be easily forced. flowering of LD and SD photoperiodic the 13-hour photoperiod but their At Michigan State University, we con- plants, respectively. Flowering of LD flowering was delayed, and all plants ducted container production trials plants is hastened when the forcing flowered rapidly when grown under on chasmanthium, and our research- photoperiod exceeds a critical value, photoperiods of 14 hours or longer based results and production notes are known as the critical photoperiod. or the night interruption treatment narrated below. An experiment was performed to de- (Figure 2). Hence, chasmanthium is an termine the critical photoperiod for obligate LD plant with a critical photo- flowering of Chasmanthium latifo- period of 14 hours. Plants forced under lium. The plugs were planted and a 24-hour photoperiod flowered quick- grown at 68˚F under a 10-, 12-, est (in five weeks), while seven to eight 13-, 14-, 16- or 24-hour photo- weeks were required for flowering period. All photoperiods were when forced under photoperiods of 14 provided by extending the nine- hours or longer. hour day using incandescent lamps. Another treatment con- Production Notes: sisted of natural days extended Starting Material and Bulking with light from high-pressure Chasmanthium latifolium seeds are vi- sodium (HPS) lamps to create a able and germinate easily. Hence, this 16-hour high-light photoperiod. grass is easy to produce commercially Plants under this treatment by seed by either germinating seeds received ≈30 percent more total in a propagation facility or purchasing light compared with the other seedling plugs. Cooling chasmanthi- treatments. Additionally, um seedlings in plug trays at 41˚F for Figure 2. Chasmanthium latifolium is an obligate long-day plant and flowered completely when non-cooled plants were forced a separate group of 15 weeks did not influence flowering at 68˚F under photoperiods of 14 hours or longer. 16-INC and plants was forced under and therefore, chasmanthium does not 16-HPS refer to a 16-hour photoperiod provided by incandes- a four-hour night inter- require vernalization for flowering. cent and high-pressure sodium lamps, respectively. Four-hour ruption provided by Although bulking is not necessary night interruption in the middle of night is denoted by 4 NI. incandescent lamps. for flowering, growing plants to their desired final size prior to forcing is when some beneficial. Plants should be bulked ornamen- under photoperiods less than 14 hours tal grasses, to maintain vegetative growth and including promote tiller production to obtain chasman- robust plants. thium, are grown in this Forcing peat-based As previously described, LD photo- medium, leaf periods of 14 hours or longer promote chlorosis is flowering of chasmanthium. Long-day observed. photoperiods can be provided as a day When left FIgure 3. Leaf chlorosis observed in Chasmanthium latifolium was extension or a four-hour night inter- unattended, corrected by application of iron chelate at the manufacturer’s ruption treatment. When forced under foliar chlorosis recommended rate. Non-treated control plants (left) and plants 14- or 16-hour photoperiods or night can progress that received a media drench of iron chelate (right) were photo- interruption, plants flowered in seven to to leaf necrosis graphed four weeks after the chelate application was made. eight weeks in a greenhouse with an av- and diminish erage daily temperature of 68˚F. Forcing the plant quality. Foliar tissue analysis soon after media drenching. GG can be accelerated by providing continu- indicated that this foliar chlorosis is About the author: Sonali Padhye is a ous light (24-hour photoperiod), with due to iron deficiency. Application of post-doctoral research associate and complete flowering in ≈5 weeks. When chelated iron such as a foliar spray of Cathy Whitman is a research technician at Michigan State University. They would provided with supplemental lighting, diamine triamine penta acetate (DTPA) like to thank private greenhouse grow- plants produced twice as many tillers or a media drench of ethylene diamine ers and horticulture suppliers that have as plants forced under natural daylight. dihydroxy methylphenyl acetate funded most of this research. For more information, please contact Sonali Padhye Therefore, a high-light environment will (EDDHA) can correct these deficiency ([email protected]) or Cathy Whitman produce higher quality crops. symptoms when applied at the manu- ([email protected]) at 517-355-5191 x facturer’s recommended rates (Figure 1-345. To become a floriculture research partner with MSU, please contact Erik Nutrition 3). EDDHA is a red-colored compound Runkle ([email protected] or 517-355- We have successfully used a peat- and if splashed on the foliage, an 5191 x 1-350). Research on herbaceous perennials is one of the objectives of the based medium to grow hundreds unsightly red residue is left behind. Floriculture Research Program at Michigan of herbaceous perennials. However, Hence, the foliage should be rinsed off State University.

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