- 3 ways for how to grow ornamental grass from seed
- Method #1: Starting single seeds in seed growing pods, indoors, early to mid spring.
- Method #2: Starting a clump of grass seed into a single growing pod, indoors, early to mid spring.
- Method #3: Planting grass seed in clumps directly into the ground, outdoors in the fall.
- Supplies to grow ornamental grass from seed indoors
- Detailed steps to grow ornamental grass from seed indoors
- Three main points to remember if you want to grow ornamental grass from seed are:
- Family and Friends
- Temperature Classifications
- Geometric Profiles
- Soil, Light, and Fertilizers
- Gardenscape Design Tips
- The Long and Short of It
- An Introduction to Ornamental Grasses and Grasslikes for Southern Gardeners
- Dr. Mack Thetford
- Easy to Grow Perennials: Ornamental Grasses
- Growing Ornamental Grasses
3 ways for how to grow ornamental grass from seed
If you’d like to learn how to grow ornamental grass from seed, I can tell you that I’ve learned a few tricks while experimenting last spring. Part of my seed growing challenge was growing several types of native prairie grasses which can also fall into the ornamental grass category.
There is probably no one, exact, right way to start ornamental grass from seed, but for practicality purposes, I’ve found that there are a few ways this process can be done with success. After trying several methods, method #2 worked best for us, but all 3 ways should work, provided you follow the seed packet’s suggestions. See, how to read and understand seed packets, here.
Method #1: Starting single seeds in seed growing pods, indoors, early to mid spring.
Planting 1 or 2 seeds into a seed pod is a slower method, but works in the long run.
Starting ornamental grass seed by planting 1 or 2 seeds per growing cell will work, just not as fast as method #2. And mind you, this was the suggested method on the seed packet. Not wanting to get creative and ruin the seed, this is how I stared my first batch of prairie grass seed.
This photo shows 5 mature single seedlings planted into a clump form.
The good news is, I was able to fix this problem, or perhaps I should say speed up the process. If you do decide to grow 1 or 2 seeds per growing cell, you can transplant them into a clump, when planting to ground. The photo above shows how I took 5 single, mature grass seedlings and planted them as a group, or clump.
This photo shows the same clump, one month later.
After one month, the grouping started to form a nice clump that will show very nicely the following year.
Method #2: Starting a clump of grass seed into a single growing pod, indoors, early to mid spring.
This is a photo of rye grass (aka Easter grass), but it’s a good example of what the pods will look like with a scatter of seeds rather than just 1 or 2.
Last spring I grew some Easter grass. I scattered a bunch of the grass seed into each pod. The grass seed grew into beautiful clumps of Easter grass. I had to wonder if I could grow my prairie grass the same way.
I gave it a try and sure enough, growing the grass seed clump style in the seed starting pots worked really well. Note: some of the seed types don’t germinate as fast, and some prefer seeding directly to ground, but all in all, this method worked best.
It’s really that simple, and as long as you water and care for the grass per the recommended steps on the seed packet. You also want to make sure the perennial grass is a proper fit to your growing zone.
Method #3: Planting grass seed in clumps directly into the ground, outdoors in the fall.
While some types of grass will work well started indoors, many of the grass seeds can be planted clump style right into your garden in the fall for a spring or summer bloom the following year.
That brings us to the third way you can start ornamental grass from seed. And that is to plant seeds in groupings right into your soil. This would be as opposed to planting 1 or 2 seeds spaced out as you might do when planting certain vegetables. Now I can’t say that spacing out 1 or two seeds every few feet won’t eventually get you healthy clumps of ornamental grass, and boy that would save money, wouldn’t it. But the desired result of a nice, healthy clump of grass will take a lot longer to form, and all of the weeding you would have to do in the meantime could be frustrating.
If you decide to plant your ornamental grass seed right into the ground, one tip that I would suggest is marking off the area where the seeds have been planted. One good way to do this would be to cut the bottom 2/3rds off of a plastic planting pot and place the remaining circular piece into the soil around the grass seed. Including a plant marker will also help, if you are planting several different types of grass seed. The main idea, here is to be able to follow the progress of the seedlings while not confusing them with other plants or weeds that will most like start growing around the seedlings.
One last point to mention, if you’d like to plant the grass seed directly into the ground, is to make sure the area you are planting in is not going to get flooded during the first few months of seeding. We get heavy rain storms in the spring and fall where I live. That is why starting the grass seed in pods and transplanting to the ground turned out to be the best method for us, at least for that area of your yard. Some types of grasses, especially prairie varieties, actually grow best when planted in the fall, directly to ground.
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Supplies to grow ornamental grass from seed indoors
Seed starting soil
Seed growing trays – or – peat pots and planting trays
Plastic wrap (aka Saran Wrap)
Spray water bottle
Detailed steps to grow ornamental grass from seed indoors
Pour some of the seed growing soil into a bowl or container.
Dampen the soil by holding the container under the faucet. Stir the soil well the even out the dampness. Don’t soak it too much, just enough to dampen.
Fill the planting cells with the seed growing soil to just below the top. I used a spoon to scoop the soil into the pods.
Sprinkle the seeds onto the top of the soil. Tamp down.
Spritz the top using the spray water bottle.
Cover with plastic wrap.
Store in a warm area that gets part sun part shade.
Once a day, pull back the plastic and spray the soil with the water bottle.
Depending on the type of seed, seedlings will begin to sprout within 2 to 3 weeks, in most cases.
After seedlings have sprouted and strengthened for about 2 weeks, move them to the outside for the hardening off period, once there are no signs of frost outdoors.
Three main points to remember if you want to grow ornamental grass from seed are:
Ornamental grass typically shows best when grown in clump form.
When trying to choose which ornamental grasses to grow, keep in mind that the grasses that are more native to your area and proven to grow in your climate will do the best.
Not all ornamental grasses are the same. Make sure to read seed packets for the best method suggested to start that type of ornamental grass from seed.
Ornamental grass, whether native or not, can add depth to your landscape. Growing ornamental grass from seed is one way to save money, experiment and enjoy creating your own unique landscape or garden.
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How does your garden grow?
Well, we know that trees and shrubs are the “bones” of a garden – they provide a framework around which we can create an overall structure or theme.
Perennials are reliable performers that flesh out the bones by adding shape, color, texture, and fragrance.
And annuals are a bit like adding jewelry to the garden body – they add a vibrant splash of decorative color.
So, where do the grasses fit in?
Ornamental grasses present a unique design element as they can be used in all settings – as part of the bones, the flesh, or as decorative accents.
With graceful motion, attractive form, interesting texture, and striking colors, their appeal is immediate.
Mix textures and forms for added interest. Photo by Lorna Kring.
A wonderfully diverse group of plants, grasses and sedges are carefree, easy to grow, and not too fussy about soil or light requirements.
Ornamentals are noted for their elegant habits – short, mounded tufts; tall, swaying seedheads; feathery textures; and a lovely array of colors all add striking beauty and captivating visual interest to the garden.
Long lasting, several varieties will put on multi-season displays, with seedheads and stalks making an attractive addition to flower arrangements, either fresh or dried.
And many varieties retain their form and color over the winter as well.
Let’s have a look at how to select these plants by their classifications, their growing requirements, how to prune and divide, and finish up with a few tips for their effective use in the garden.
Family and Friends
When we use the term “ornamental grasses” we’re referring to a group of plants that look like grasses and have similar growth habits, but aren’t restricted to the true grasses of the Poaceae family.
For example, sedges and carex belong to the Cyperaceae family, while rushes belong in the Juncaceae clan. And specimens such as black mondo grass belong to the Asparagaceae family – the same tribe as asparagus!
For the large part, this group is wonderfully disease and pest-free, with few problems from insects, bacteria, and fungi.
And once established, many prove to be drought tolerant as well, even in severe situations – although they may go dormant for a period to conserve energy. This makes them perfect for xeriscape style landscaping applications.
For the large part, this group is wonderfully disease and pest-free, with few problems from insects, bacteria, and fungi.
What does all this mean to us gardeners? Well, it means that there’s an incredible selection of ornamentals we can use to great effect in the garden – from evergreens to heat lovers to those that thrive in moist, shady environments.
Naturally, because of this vast diversity, there can be some confusion regarding planting requirements and best locations, as well as successful pruning and division.
To make sense of their many different characteristics and requirements, let’s start at the start, which is how they’re classified.
Grasses are first defined by their temperature preferences, then by their growth habit.
In general, most will fall into the two categories of cool season or warm season varieties, depending on when growth is most prolific.
Cool Season Varieties
This category includes many of the evergreens.
They put forth the greatest growth spurts in the cool months of spring, and to a lesser degree, in late summer and early autumn – with a temperature preference in the range of 60-70°F.
Cool season growers emerge in early spring and usually produce seed heads by early summer, and they don’t appreciate intense heat or dry conditions. These types will often die back or go dormant in hot conditions, and rebound once the summer’s heat has passed.
Warm Season Varieties
These are just the opposite. They emerge in late spring once temperatures have warmed up, and thrive in the hot days of full summer – with a penchant for temperatures in the range of 80-95°F.
These varieties put on their best display in intense heat, and many will produce showy seedheads that last into autumn.
Some varieties display attractive seed heads. Photo by Lorna Kring.
Growth will come to a halt with cold temperatures or frost, but several varieties will also continue to provide winter interest with stalks and seeds that dry and change color to glowing, burnished tones – making an attractive and natural “dried flower arrangement” in the garden.
After the temperature classification has been determined, it’s useful to know their growth habits, as this will help you to decide where, and how, to use them in your plantings.
The second classification is determined by their geometric profile or architectural shape.
Most ornamentals are clump-forming and non-invasive – which makes them a good choice for mass planting, or introducing into the garden as a specimen plant.
These grasses range from short to tall, and display an excellent diversity of form. The most common of these are:
Relatively short growth that spreads equally in all directions, like erect porcupine quills.
Blue oat grass in the foreground is an example of the tufted shape. Photo by Lorna Kring.
Stalks grow upwards, then bend over and down to the ground, with a shape like mushroom caps.
A mounded shape. Photo by Lorna Kring.
Mid-height stalks remain upright in a tight grouping.
Stalks in an upright form. Photo by Lorna Kring.
These have upright stalks that spread out in a fan-like shape.
An upright divergent shape. Photo by Lorna Kring.
Arching forms are mid-sized to tall varieties with straight stalks that arch over, like a rooster’s comb.
Variegated color in an arching form. Photo by Lorna Kring.
Similar to arching, but the straight base is taller and only the top third or so bends over, with a shape like the profile of an umbrella.
Giant miscanthus, an upright arching form.
Creepers, Spreaders, and Runners
The other main category includes those that spread by rhizomes or stolons, and have growth patterns known as creeping, spreading, or running.
These can be quite invasive, and because of their aggressive growth habits, are most often used as a ground cover.
However, they can also be used elsewhere in the garden by keeping their root spread in check.
The easiest way to do this is by planting them in a large nursery container (like the ones that trees and shrubs come in), then sinking the grass – container and all – directly into the soil.
Keep in mind that if you want to restrict their spread, the rim of the pot should be level with, or just above the soil.
Depending on the growth habit of the plant, you may also want to first cut out the bottom of the pot, and double dig the soil to ensure the roots grow straight down, not sideways.
The Encyclopedia of Grasses for Livable Landscapes
With so many types to choose from, it’s always handy to have up a good reference book to check, like The Encyclopedia of Ornamental Grasses for Livable Landscapes by Rick Darke – it has some gorgeous photos and great ideas. This book is available on Amazon.
Soil, Light, and Fertilizers
Grasses usually aren’t fussy about the type of soil they grow in. Several varieties actually prefer poor soil, without the need for fertilizers.
However, most do enjoy a well-drained location and a loamy garden soil, with plenty of organic compost or rotted manure mixed in when planting.
Add some bone meal to the planting mix and an all-purpose fertilizer such as 10-10-10 to provide an adequate supply of nutrients to establish the roots. We recommend GreenView Multi-Purpose 10-10-10 Fertilizer, available on Amazon.
Lebanon Seaboard Corporation GreenView No.33 10-10-10 All-Purpose Fertilizer
Once they’re established, the same all-purpose fertilizer can be applied once in the spring as new growth emerges.
Avoid over-fertilizing your ornamental grasses, as too much of a good thing can weaken stalks and cause them to suffer in winter cold.
Most ornamentals will enjoy six to eight hours of sunlight per day.
There are exceptions, of course, such as black mondo, Norther sea oats, and many sedges, which are happier in a shady spot.
Watering may be roughly defined according to their temperature classifications, with true grasses and warm season varieties preferring drier conditions, while several sedges, carex, and cool season growers prefer moister conditions.
For accurate watering and light requirements, refer to the particulars for each individual species to ensure they are provided with the best conditions for healthy growth.
Good drainage is another factor that’s important to the success of ornamental grasses, even for those that prefer a high-moisture environment.
If drainage is an issue in your garden, add 4 to 6 inches of pebbles at the bottom of the planting hole, and mix some sand into the soil.
Simple to grow, most do well in containers. Photo by Lorna Kring.
For containers, ensure the pot has plenty of drainage holes and 1 to 2 inches of drainage material covering the holes.
As with all plants, ornamentals range in hardiness ratings, so check the plant’s hardiness zone to ensure it will work in your climate.
For areas with harsh winters, a thick, dry mulch may be needed to protect some of the more tender varieties.
Like most perennials, ornamental grasses are best planted in the spring or fall.
Spring planting allows the roots to become well established before cold weather sets in. But if you need to plant in the autumn, do so from mid-August to the end of September, and provide a dry mulch for the first winter.
Create a planting hole twice as wide but no deeper than the root ball. Amend the soil with some organic material, such as compost or well-rotted manure, and the 10-10-10 fertilizer mentioned above.
Soak the planting hole thoroughly before settling the roots in place, fill in with soil just to the crown, firm the soil, and then water to settle in place.
For containers, ensure the pot has drainage holes and plenty of drainage material, then fill it to an appropriate depth with the soil mix outlined above. Plant, firm it in place, and settle with a long drink of water.
General pruning requirements are loosely based on temperature classifications.
Cool season varieties, including evergreens, should be cut back in late winter or very early spring – but proceed with caution! A harsh pruning can result in irreparable harm.
And as many of these types are slow growing, a severe cut can result in a sad, stubby little clump for a couple of years as it tries to recuperate. (Lesson learned – never allow helpful spouses near cool season varieties with sharp scissors!)
To prune cool season growers, cut back by two-thirds at the most, leaving one-third to one-half of the base in place.
For those that are evergreen in nature, a better option can often be a simple groom and trim.
To groom, use a small hand-held rake and work the tines into the base of the plant, then draw the rake up and out, removing any dead stalks.
Or, use your hands, working your fingers into the base, then repeating the drawing motion. Be sure to use gloves for this, as many grasses have sharp edges that may cut.
After raking, cut away any remaining dead growth around the clump’s outside perimeter.
One groomed, a light trim of the tips will usually suffice. To trim, bundle the stalks together, then cut with sharp garden scissors on a diagonal – from just below the dead material to the center of the bundle. Make several small cuts in this manner all the way around the bundle.
This can create a slightly blunt-tipped appearance, but new growth will quickly soften the tips.
Pruning warm season grasses is more straightforward, with stalks simply cut back close to the ground.
Grasses add winter interest.
Once cold weather arrives and the heat lovers turn brown, they can be cut back at any time.
If you enjoy their dried look in the garden, leave them over winter to add interest to the garden, along with seeds for visiting birds.
Just ensure they’re cut back to a few inches by mid-spring, before new growth emerges.
Propagation of ornamental grasses can be done either by seed or root division.
Creating new plants from seed can be hit or miss with many varieties, as several have sterile seeds that won’t germinate.
On the other hand, several species can easily be grown from seed and will self-seed readily in the garden.
Check your species to determine if seeds are viable for planting; if so, collect seeds from summer to fall.
In early spring, plant seed in small pots in a light, sandy garden mix. Provide them with water, plenty of morning sunlight, and adequate temperatures – you may want to put them in a greenhouse or cold frame to help germination.
Leave seedlings in small pots for one to two years. Photo by Lorna Kring.
Once the seedlings are a few inches tall, place them in a sheltered spot in the garden where they’ll receive morning or dappled sunlight and adequate moisture.
Give them a little sip of all-purpose fertilizer or top dress with a bit of organic material, then forget about them for a year or two until they’re big enough to go into the garden.
Division is an easy and reliable way to multiply ornamental grasses, and to rejuvenate older clumps that have died out in the center.
However, this must be done while the plant is in an active growing stage, but not flowering – grasses that are transplanted while in dormancy will struggle to develop a healthy root system.
As a rule of thumb, cool season varieties should be divided in early spring, or late summer/early fall.
However, evergreens should only be divided in spring, to ensure they have time to recover and develop strong roots before facing their first winter.
Warm-season types can be divided from the time new growth emerges in mid- to late spring until mid-summer.
To propagate by division, small to mid-sized clumps can be divided in the same manner as for dividing perennials:
1. Prepare the new planting site(s) or container with the soil mix outlined above.
2. Dig up the clump along the outside drip line, then divide it into smaller sections with a sharp knife, saw, or spade, ensuring each section has healthy roots and stalks.
3. Clean and remove any sections that have died out.
4. Set the root ball in place, following the planting instructions above.
Of course, if the heart of the plant is still healthy, it can be left in place and divisions taken from the outside edges.
Larger stands can be a touch more challenging!
The process is the same, but if the stand is really large, you may need two or three strong backs and shovels to work out an entire root system. Employing levers helps with these big boys, so have a good selection of strong shovels, wedges, pry bars, and fulcrums to get the task done.
It may be easier to handle these large clumps by taking sections from the outside perimeter rather than trying to remove the whole root ball in one piece.
However, this means having to cut through some of the root mass in place, which can be incredibly dense and tough – even a very sharp spade can be inadequate for cutting through mature, thick roots.
You may have to resort to using a handsaw, reciprocating saw, a hatchet, or even a splitting maul to divide the roots.
Cut the grass back close to the ground, and starting in the soft soil of the drip line, cut towards the middle of the plant, creating wedges with whatever tools will work.
Pry or dig out the wedges, then clean, divide, and replant as for small species.
Divide large plants about every three years, or when you notice the center dying out.
Single specimens grown in pots will need division every 2 to 3 years.
Gardenscape Design Tips
With their stunning variety, ornamental grasses can be used in multiple garden settings.
They can be used either alone or in combination with other grasses, flowers, shrubs, and trees, or in planters, to provide a soft, fluid texture with a delightful array of colors – blue, green, chartreuse, gold, bronze, orange, red, and even black are readily available.
Cultivars that grow from 5 to 12 feet – such as full-sized pampas, millet, or maiden grasses – make a dramatic and distinctive focal point, and provide a delightful sense of flowing movement with just the hint of a light breeze.
Plumes of pampas.
Use the tall varieties as part of your skeletal garden structure by planting them as stand-alone specimens, to anchor a large-bed arrangement, or in masses for a privacy screen.
Varieties like little bluestem, fountain, and switchgrasses are well suited to flesh out the bones.
Use them to create a second tier of interest in mixed bed plantings, as a single specimen in their own containers, as elegant accent pieces when used singly, or to provide the elements of balance, harmony, and rhythm when used in pairs or multiples.
Small, Tufted Varieties
Small types such as black mondo and Japanese forest grass, as well as the colorful carex varieties, are outstanding as decorative jewels in the garden.
Carex makes an excellent border. Photo by Lorna Kring.
They’re a knockout for garden bed borders, to soften rockeries and retaining walls, to line pathways, when added to mixed containers, and to fill in bare spots.
For Natural Settings
Grasses combine very well with companion plants that have similar habitats and growth habits, such as non-invasive perennials and self-seeding annuals.
Bachelor’s buttons, bee balm, black-eyed Susans, California poppies, chamomile, coneflowers, dame’s rocket, daisies, California poppies, flax, foxglove, lupines, meadow mixes, poppies, and yarrow all combine well for a delightful, natural look.
The form and texture of grasses can be used to great advantage to provide contrast and make other specimens “pop.”
Try flanking spiky Russian statice or prickly globe artichoke with dreamy clouds of mounded carex, or border rigid hedges of boxwood with flowing feather grasses. Experiment and have fun with different pairings to find the effects that works best for you.
The Long and Short of It
From small bunny-tail tufts to majestic stands of giant miscanthus, there’s a size, texture, and color of ornamental grass suitable for any setting.
Easy to grow and propagate, ornamentals are an excellent investment for the gardenscape that provide years of graceful interest.
Grasses come in many colors. Photo by Lorna Kring.
Choose your grasses based on cool and warm season growth habits, then select the shapes, sizes, and colors that work for your chosen location(s).
Divide every three years or so, and you’ll have a constant supply of low-maintenance plants that add superb beauty and grace to your garden!
Do you readers have any questions about ornamental grasses that we can help out with? Drop us a line in the comments below, or join the conversation on our Gardener’s Path Facebook page!
Photos by Lorna Kring, © Ask the Experts, LLC. ALL RIGHTS RESERVED. See our TOS for more details. Product photos via Lebanon Seaboard and . Uncredited photos: .
About Lorna Kring
A writer, artist, and entrepreneur, Lorna is also a long-time gardener who got hooked on organic and natural gardening methods at an early age. These days, her vegetable garden is smaller to make room for decorative landscapes filled with color, fragrance, art, and hidden treasures. Cultivating and designing the ideal garden spot is one of her favorite activities – especially for gathering with family and friends for good times and good food (straight from the garden, of course)!
An Introduction to Ornamental Grasses and Grasslikes for Southern Gardeners
Dr. Mack Thetford
Associate Professor of Environmental Horticulture
University of Florida, West Florida Research and Education Center, Milton, Florida
Ornamental Grasses. Mention this diverse group of plants and you will evoke a variety of mental images for American gardeners. Amber waves of grain, prairie scenes, marsh grasses or the blanket of sea oats along our coasts. Ornamental grasses are a very popular group of plants which have become an integral part of many southern gardens. The availability of a large number of species and cultivars makes this group of plants very versatile with many potential uses in the home landscape. The popularity of this group of plants is, in part, related to the diversity of plants represented. Additional factors attributed to this popularity include ease of culture and tolerance of a broad range of environmental conditions such as drought or boggy, wet areas. The following information should assist the first time gardener as well as the experienced gardener in the selection and use of ornamental grasses.
The first step to proper selection and use of ornamental grasses must begin with an understanding of the broad diversity of plants represented by the term ornamental grass. The term Ornamental Grass is one of those catchall phrases used to describe not only true grasses but other related plants as well. While all of these plants are grasses in the sense that they are monocots, the parallels stop there. It turns out that many of the plants we commonly refer to as grasses are not really grasses but are members of plant families that botanists and gardeners refer to as the grasslikes. The grass family is called Poaceae, although some botanists refer to the grass family by the older family name of Gramineae. The grasslikes generally fall into one of two plant families; the Rushes, which represent the plant family Juncaceae, and the Sedges, which represent the Cyperaceae family. All three plant families contain plants adapted to a wide variety of habitats and planting conditions. Within each of these plant families one may find individual species adapted to wet or dry, sun or shade, hot or cold climates or any combination thereof. Growth habits are equally diverse representing low ground covers to intermediate shrub-like to very tall hedge-like plants.
Using grasses in the landscape can be an overwhelming task for beginning gardeners, there are many species and cultivars to choose from and so many design possibilities. Ornamental grasses are very dynamic and do not maintain a permanent structure in the garden like most of our shrubs and trees. The size, shape, texture and color of grass will change with every season. Deciding how to use ornamental grasses in the landscape becomes a relatively easy process when we consider a few plant characteristics. The first characteristic to consider is if the plant is an annual or perennial. A perennial grass will live for many years while an annual grass will only last one season and will die after flowering or it may be killed when exposed to freezing temperatures. Other characteristics to consider when making your grass selections include growth form, mature size, if the foliage is winter hardy (evergreen) or not (deciduous), foliage color, and time of flowering. While much of this information should be available from catalog descriptions, it is important to understand how these characteristics can be used to your advantage when designing your garden.
Ornamental grasses can be classified into two fairly distinct categories based on their growth form. There are clumpers and spreaders and the spreaders are often called creepers. The clumping grasses increase in size each year by forming new divisions called culms. This results in the plant increasing in width at its base but basically remaining in the same position over time without spreading to other locations in the garden. The spreading grasses differ by increasing in size each year by forming rhizomes or stolons. These grasses may also increase in size by forming culms in addition to the rhizomes or stolons. Rhizomes are below ground stems while stolons are aboveground horizontal stems. These structures allow this type of grass to spread in any direction from the original plant and the spreading or creeping characteristic often results in these grasses being used as ground covers.
The mature size of an ornamental grass is an important aspect to consider when selecting the proper plant for your landscape design. The interesting thing about these plants is that the height, foliage spread, and overall shape may vary by season. Even the tallest of grasses may only be a few inches tall in the spring following an annual pruning. The height will increase dramatically over the spring but if you are using a tall species for screening unwanted views it is important to keep this in mind as you make your selection. Foliage spread and understandably, overall plant form will also vary with the season. An interesting transformation will occur as new foliage is produced in the spring resulting in an upright narrow plant that may become a vase-shaped plant by summer while flowers emerging in the fall may make the plant appear more rounded. Regardless of the mature size or growth form of the grass selected, the ornamental grass gardener should be prepared for a dynamic garden offering a great deal of interest for all seasons.
Foliage Color and Hardiness are important considerations when selecting ornamental grasses. The foliage of ornamental grasses offers a veritable pallet of colors ranging from greens, grays, blues, and browns to yellows and creams. Foliage patterns are equally diverse with variegation patterns of horizontal or vertical stripes. The interest doesnt stop there. Fall colors can range from yellow to orange to red while winter color can vary from light tan to dark brown. Regardless of the season, ornamental grasses can provide a striking contrast of color, create an accent or focal point, or they can provide very subtle greens and grays to create a backdrop for other plants in the garden.
Fall and winter color will vary greatly based on your gardening location. The weather patterns in your location will influence foliage hardiness. Grasses for which the foliage is winter hardy are often referred to as evergreen while grasses for which the foliage is not winter hardy are often referred to as deciduous. Many of the deciduous grasses will have the potential to add fall and winter color to your garden while the evergreen grasses can serve as the foundation for creating bold or dramatic color contrasts.
The Time of growth and flowering may be an important consideration in the selection of ornamental grasses. Many cool season grasses flower in the spring. Cool season grasses grow primarily in the cooler months and are dormant through the hot or dry months. Warm season grasses may flower throughout the summer or in the fall. Warm season grasses grow primarily in the warm months and are dormant through the cooler months. Flowering is the primary selection criterion for many gardeners since many grasses will retain their flower heads for many weeks or months after the seeds are formed. For this reason, pruning grasses immediately after flowering is generally not recommended. Allowing the flower heads to remain through the winter months not only extends the flowering period but retains the aesthetic value of the grasses until spring.
Pruning of ornamental grasses should be scheduled for early spring just prior to new growth. Evergreen grasses may only require the removal of old flower stalks while deciduous grasses may require complete removal of the dead foliage and flower stalks from the previous season. Grasses usually do not require pruning during the growing season except for those creeping grasses getting too close to the lawn. Much aggravation can be avoided by separating your grasses from the lawn with a minimum of 1 to 2 feet of mulched buffer zone. This buffer will allow easy removal of lawn or ornamental grasses before they become intertwined.
Landscape establishment of ornamental grasses will require preparation of the planting site. You should follow the established recommendations for your location to ensure the pH and fertility are appropriate. Your local garden center or County Extension Agent should be a great source for information and soil test kits. Remember, ornamental grasses, just like other plants, should not be planted any deeper than the top of the original rootball. Just like strawberries, the crown (the root and shoot junction) of grasses should be located at the soil line. Watering during establishment is a must! Regardless of how drought tolerant a grass species may be we should always water the original rootball of the transplant and the surrounding soil until the plant has roots established in the native soil of your garden. If you must irrigate, consider a drip irrigation system rather than an overhead system. The overhead irrigation will be harsh on the delicate flowers of the grasses and may diminish the impact of the flowers or shorten the flowering period.
Since ornamental grasses are a relatively new group of plants for our southern gardens, many local garden centers may not have very large selections. Don’t be bashful if you don’t find the grass you are looking for, ask your local garden center to locate and stock these plants. For those selections you do find locally, be prepared to see plants that may not be as attractive as those pictured in catalogs and magazines. Many grasses, especially those that quickly reach heights above 3 to 4 feet, may require pruning during the production cycle to prevent the wind from toppling the plants. Tall plants are also difficult to ship from the grower/producer to the garden center so this may make some of the larger, taller selections a bit more difficult to locate. Remember, the way a grass looks in a pot at the garden center may not reflect the ultimate appearance or size it will have once established in the garden.
Mention of products, services or companies does not imply an endorsement by the University of Florida. This article and the “Gallery” which follow are together published as the Florida Agricultural Experiment Station Journal Series number – T0480
Dr. Mack Thetford is associate professor of environmental horticulture, University of Florida, West Florida Research and Education Center, Milton, Florida. He can be reached at his email for further information.
Easy to Grow Perennials: Ornamental Grasses
The Low Maintenance Unicorn
Are you tired of tending to your perennials to keep them looking good throughout the growing season? What if I told you there’s a plant that needs care only once a year and requires only that you cut it down? And that once established, you don’t even need to water it? Yes, it’s true, this unicorn exists! It’s not just one plant; it’s a family of plants: ornamental grasses.
There is a myriad of varieties, and the versatility of ornamental grasses is unmatched in the landscaping business. Whether you’re looking for height or a groundcover in shade or sun, wet or dry conditions, there is an ornamental grass to fulfill your need. They have minimal insect and disease issues, are drought tolerant and require little maintenance and no supplemental watering. When it came to planting my very small patch of garden in an urban space, I took into account my schedule and the lack of time I could dedicate to the garden (and in all honesty, my laziness); what go-to plant do you think I reached for? You know it, ornamental grass!
Sun Loving Grasses
These tall sun-lovers are all clump-forming species that shine during the growing season and add texture in the winter season with their straw color; they look especially majestic when topped with tufts of snow in winter. They can be cut down close to the ground in spring, or if you really want to, in late fall, but you’ll be missing out on the winter interest if you do so.
- Calamagrostis x acutiflora ‘Karl Foerster’ starts growing in early spring with lush green basal growth to 2’ and then has upright, wheat-colored plumes to 4-5’ in full sun/partial shade. Great when planted en masse, you can leave the foliage up for winter as it takes on a new beauty with snow-covered plumes.
- Miscanthus varieties offer rapid vase-shape growth once the heat of late spring/early summer kicks in culminating in a graceful, arching habit, topped by beautiful, wispy flowerheads in late summer/fall; these too look majestic when snow covered. ‘Morning light’ is a trusty, neat standby with thin blades that grow to 4-5’. ‘Adagio’ grows to 2-4’ where a shorter plant is needed. ‘Purpurascens’ adds a tighter upright habit with stunning 3-4’ fall foliage turning orange-red. Great as a stand-alone plant or massed.
- Panicum varieties have upright growth with airy seed heads in late summer fall. ‘Shenandoah’ has green foliage turning red in July and then deep crimson in fall while growing to 4’; ‘Cloud Nine’ has strictly upright blue green foliage growing to 8’.
Unique Ground Covers
These shorter varieties are my favorite ground covers for shady areas where you need some bright foliage.
- Carex varieties – (technically these are sedges) ‘Ice Dance’ and ‘Kaga Nishiki’ are great clump forming, variegated plants to 12” that can widen out quickly and even colonize. Super easy to establish and needs nothing but a haircut once a year in spring before new growth and the cool, spiky flowering bodies emerge.
Shady Lawn Solutions
Looking to replace a shady lawn area where the grass won’t grow? Use Carex ‘pennsylvanica’ as an alternative. The razor thin blades look like our lawn turf, but don’t need mowing but once a year. How great does that play into my laziness theme? Pennsylvanica grows to about 8” and then flops over, making for an elegant mass in the landscape.
Most properties have at least a few low-light areas. These ornamental grasses can survive, and even thrive, in those shaded spots.
- Hakonechloa – variegated (‘Aureola’) or bright chartreuse foliage (‘All Gold’) provides a wide tuft of light grass that moves with even the faintest of air movement. Great contrast in dark areas.
- Pennisetum grows in full sun with a wide fountain shape, hence its common name of fountain grass. Great easy groundcover in diminutive sizes such as ‘Piglet’ and ‘Little Bunny’, up to the species which can be 3’ high and wide. Tried and true ‘Hameln’ is my favorite with its bottlebrush inflorescences coming about in late summer/early fall. The low sun in autumn backlighting these flowerheads is spectacular- a real treat and contrast to all the red and oranges of autumn.
An (Almost) Effortless Garden
With all the time saved by not having to tend to your newfound favorite family of plants, you can concentrate on the busy parts of life while knowing your garden looks great. There are countless others to mention but start with these and see how quickly your love for ornamental grasses will grow!
Growing Ornamental Grasses
Review these basics of growing ornamental grasses to decide if these low-maintenance plants belong in your landscape.
What does an ornamental grass bring to the garden party?
These perennials are unequaled for introducing texture to garden plantings. Many also provide outstanding winter interest. Grasses offer two things to the garden that many plants cannot: movement and sound. A gentle breeze rustles stems against one another and creates a ripple of motion that steals the show. Grasses also offer an array of colors, including vibrant gold, fiery red, dusky black tones and variegated patterns.
Do grasses need full sun to grow?
Most grow best in direct sun and tend to become floppy in lower light. Full sun (6 to 8 hours) is ideal, but you can always try in 4-5 hours and see what happens. Some grasses thrive in low light, such as Japanese forest grass or inland sea oats.
What kind of soil do grasses require?
You can find a grass to suit any soil type. Many grasses prefer well-drained soil, but some thrive in moist soil or heavy clay. Some demand fertile soil; others grow gangbusters in poor, rocky soil. Do your homework, and choose the right grass for your conditions — or amend your soil to suit the grass you want.
When is the best time to plant?
In mild climates, you can plant grasses year-round, whenever they’re available for sale. In zones where the ground freezes, spring and early fall offer ideal planting windows. Avoid planting within four weeks of the first fall frost.
When do I fertilize?
Feed established grasses in spring and late summer. Scratch a granular slow-release fertilizer into soil around plants.
Do grasses have pests?
Rarely. You may occasionally have an Aphid or Mite attack. Squirting the grass with a strong spray of water dislodges insects. Rabbits and deer tend to leave ornamental grasses alone.
How often do ornamental grasses need division?
Most grasses can grow for many years without division. That’s part of their low-maintenance charm. Divide when the clump dies in the center. The best time to divide is in early spring, before new growth begins. Some grasses develop thick root masses that may require a chainsaw to separate.
Do I need to prune?
For most grasses, cut them back before new growth appears at the start of the growing season. In warmer zones, some grasses are evergreen and don’t really require pruning, unless dead leaves collect around the base of the clump. Remove those.
Are there any tricks to make pruning easy?
For small clumps, use hand pruners or shears. Electric hedge trimmers offer a quick pruning option, especially with large clumps. For easy clean-up, wrap a bungee cord around large clumps and cut beneath the cord. Wear gloves for protection, particularly when working with grasses that have razor-sharp edges.
Are ornamental grasses invasive?
Some species are in certain regions. Miscanthus has become a large problem in the Northeast. Fountain Grass (Pennisetum setaceum) has invaded parts of the West. You can limit the invasive potential of some grasses by removing seedheads before seeds mature. Cut just beneath the seedhead, and you’ll still have tall stems to linger through winter. There may also be seedless varieties available.
To determine if a grass is invasive in your region, check with your local native plant society or state Department of Natural Resources, or consult the Invasive Plant Atlas of the United States.