Ornamental grass

Key takeaways

Ornamental grass belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Ornamental grass to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Ornamental grass from memory before moving on to harder problems.

Reference excerpt

Ornamental grasses are grasses grown as ornamental plants. Ornamental grasses are popular in many colder hardiness zones for their resilience to cold temperatures and aesthetic value throughout fall and winter seasons.

Classifications Along with true grasses (Poaceae), several other families of grass-like plants are typically marketed as ornamental grasses. These include the sedges (Cyperaceae), rushes (Juncaceae), restios (Restionaceae), and cat-tails (Typhaceae). All are monocotyledons, typically with narrow leaves and parallel veins. Most are herbaceous perennials, though many are evergreen and some develop woody tissues. They bring striking linear form, texture, color, motion, and sound to the garden, throughout the year.

Habits

Almost all ornamental grasses are perennials, coming up in spring from their roots, which have stored large quantities of energy, and in fall or winter go dormant. Some, notably bamboos, are evergreen, and a few are annuals. Many are bunch grasses and tussock grasses, though others form extensive systems of many-branched rhizomes. The bunching types are often called "clump-forming" or "clumping", distinct from the rhizomatous types, called "running". Sizes vary from a few centimeters up to several meters; the larger bamboos may reach 20 m or more tall. Some ornamental grasses are species that can be grown from seed. Many others are cultivars, and must be propagated by vegetative propagation of an existing plant. Pampas grass (Cortaderia selloana) is easily recognizable, with semi-dwarf to very large selections for the landscape. Deer grass (Muhlenbergia rigens) and canyon prince wild blue rye (Leymus condensatus) are popular in larger settings, natural landscaping, and native plant gardens. There are Miscanthus grasses whose variegations are horizontal, and appear even on a cloudy day to be stippled with sunshine. Many Miscanthus and Pennisetum species flower in mid or late summer, and the seed heads are long lasting, often remaining well into the winter. Some Stipa species flower in the spring, the inflorescence standing almost two metres above the clumps of leaves, and again the seed heads last late into the winter. When gardening near natural Wildland–urban interfaces, one should take care to avoid planting invasive species, such as Cortaderia jubata (native to Argentina and the Andes), Pennisetum setaceum (native to northeastern Africa and western Asia), and Nassella tenuissima (syn. Stipa tenuissima; native to New Mexico, Texas, and South America). Not only do invasive species compete with native plants, but they may also increase the risk of wildfires, especially in areas such as California.

Examples

True grasses

Agrostis nebulosa (cloud grass) Calamagrostis × acutiflora (feather reed grass) - several cultivars Calamagrostis brachytricha AGM (Korean feather reed grass) Calamagrostis foliosa (coastal or leafy reedgrass) Cortaderia selloana (pampas grass) - many cultivars Deschampsia cespitosa (tufted hair-grass) - many cultivars Festuca arundinacea (tall fescue) - many cultivars Festuca californica (California fescue) Festuca glauca (blue fescue, grey fescue, ornamental blue fescue grass) - many cultivars Festuca idahoensis (Idaho fescue, blue bunchgrass) Festuca ovina (sheep's fescue) - many cultivars Festuca rubra (creeping fescue grass, red fescue, red fescue grass) - many cultivars Helictotrichon sempervirens AGM (blue oat grass) - several cultivars Leymus condensatus (giant wildrye, canyon prince, wild blue rye) Melica imperfecta (smallflower melic, little California melic) Miscanthus sinensis (Chinese silver grass, eulalia, eulaia grass, maiden grass, zebra grass, Susuki grass, porcupine grass) - numerous cultivars, several with AGMs Muhlenbergia rigens (deer grass) Panicum virgatum (switchgrass) Pennisetum alopecuroides (Chinese fountain grass, Chinese pennisetum, fountain grass, swamp foxtail grass) - many cultivars Pennisetum setaceum AGM & P. setaceum 'Rubrum' AGM (red fountain grass, African fountain grass, fountain grass, purple fountain grass, ruby grass) - & several other cultivars Pennisetum villosum AGM (feathertop) Stipa gigantea AGM (golden oats) Stipa tenuissima syn. Nassella tenuissima (Mexican feather grass, Texas needle grass)

Sedges

Carex comans (New Zealand hair sedge) - many cultivars Carex elata 'Aurea' AGM (Bowles' golden sedge) Carex flacca (syn. C. glauca) (blue sedge, gray carex, glaucous sedge, or carnation-grass) Carex oshimensis - Evergold AGM Carex pansa (sand dune sedge) Carex pendula (pendulous, hanging, drooping or weeping sedge) - & cultivars Carex praegracilis (clustered field sedge, field sedge, expressway sedge) Carex siderosticta (creeping broad-leafed sedge) - several cultivars Carex spissa (San Diego sedge) Carex several other species & cultivars (including Japanese sedges & others) Uncinia rubra (red hook sedge)

Environmental impact Some ornamental grasses have become serious invasive weeds, usually as garden escapes into natural vegetation areas.

Images

References

Illustrations

Worked examples

Example 1 — a first encounter with Ornamental grass

Start with the simplest possible case. Write down what Ornamental grass claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Ornamental grass before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Ornamental grass ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Ornamental grass

In research: Ornamental grass appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Ornamental grass in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Ornamental grass is common in secondary-school and first-year university syllabi. It links to neighbouring topics Garden plants, Grasses, Groundcovers, so understanding it makes those chapters shorter.
In everyday life: Look for Ornamental grass outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Ornamental grass in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ornamental grass means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Ornamental grass out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ornamental grass in simple terms?

Ornamental grasses are grasses grown as ornamental plants. Ornamental grasses are popular in many colder hardiness zones for their resilience to cold temperatures and aesthetic value throughout fall and winter seasons.

Why does Ornamental grass matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Ornamental grass?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Ornamental grass.