Pruning Ornamental Grasses

Who doesn?t love a garden filled with the movement and beauty of ornamental grasses especially during the fall? But how do you take care of them after the show is over for the season?

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Lomandra and NZ flax in mixed planting

When I recently received an email asking what to do with an ornamental grass that had already turned that soft tawny color I figured it was time to brush up on how to care for them. To prune or not to prune? That is the question.

Grasses are distinguished from other plant families by their growth habit. They grow upward from the base of a leaf or shoot and can regrow from the crown when cut back. True grasses generally have extensive root systems which help control erosion. There are other grass-like plants like chondropetalum, New Zealand flax, kangaroo paw and lomandra that resemble grasses in their growth habits and are often some of the best companions for interplanting with grasses.

Most grasses require little care, minimal fertilizer and only occasional grooming. Some flourish with just enough water to meet their needs while others need regular irrigation. Diseases and insect pests are rare and they are not attractive to deer. They have succeeded because of their adaptability and have evolved to suit almost every environment and climate on earth.

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Japanese Blood grass – small and goes dormant

Basically, grasses and grass-like plants fall into 4 different pruning types: Large or small types that go dormant and large or small types that stay evergreen.

Large grasses that go dormant such as miscanthus and calamagrostis are pruned yearly in late fall to late winter. It?s best to hold off on pruning as long as possible to preserve the winter interest and to provide food for birds. When they turn brown and start shedding it?s time to prune. Gather the blades together with a bungee cord or rope and cut down to 10 inches.

Small grasses that go dormant such as Japanese blood grass or fountain grass should be pruned yearly at the same time. Don?t cut them too close to the crown or you risk losing a few clumps. Cut those under 3 feet tall down to 3 inches and those that grow taller down to 6 inches.

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The Guardsman- NZ flax large & stays evergreen

Large, evergreen grass-like flax and cordyline can be pruned anytime to cleanup and resize but rejuvenation should be done mid-spring. When pruning to freshen up the foliage, select the most damaged leaves and cut them out at the base. If your plant is overgrown or suffered winter damage, prune severely in mid-spring cutting off all the foliage at the base. Tall cordyline varieties can be cut off a few feet from the ground and they will re-sprout below the cut or from the base.

Lastly, small evergreen grasses like carex, acorus, blue oat grass and blue fescue grass can be cleaned up in spring by putting on rubber gloves and combing through the grass. If this kind of cleanup isn?t enough you can reduce the height by two-thirds and in a couple of months they will look good again.

When Rainfall Causes Problems

If you were waiting for some rain before planting to control erosion wait no more. That last storm brought plenty of the wet stuff and the next round is hopefully not far off. You?ve gotten a reminder of those areas that need stabilization during the rainy season.

Fall is the perfect time to start planning and planting. The nights are cooler, the days shorter and the soil still warm. Everything that a new plant needs to get a good start.

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Steep hillside at author’s house covered with erosion control plantings

Using the right plants on hillsides can help slow, spread runoff and prevent soil erosion. Often they need to adapt to shallow, poor soil and cope with less than ideal conditions all while putting down dense, strong roots. Mulch also protects soil from direct rain impact and slows runoff across bare soils. This is important while new plants are growing in. Covering the steepest slopes with jute netting through which plants may be installed is an added precaution.

What plants are good for controlling erosion in our area? When choosing plants to cover a bank for erosion control, assess the conditions of the area you want to plant. Is it in the sun or shade? Is it a naturally moist area or dry? Do you intend to water it or go with our natural cycle of wet in the winter and dry in the summer? Matching the plant to the site conditions will ensure success. California natives are well suited to this job.

If the area you need to stabilize is large and mostly shade, consider ribes viburnifolium or Evergreen Currant. Like mahonia repens or Creeping Mahonia it needs no irrigation when established. Another native, the Common or Creeping Snowberry can also hold the soil on steep banks, spreading by underground stems that stabilize the soil.

A bank in the sun would contain a different plant palette. Common native shrubs for sun include ceanothus groundcover types such as ?Centennial?, ?Anchor Bay? and maritimus that are not attractive to deer like the larger leaved varieties. Manzanita are also excellent at controlling erosion.

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Western mock orange aka philadelphus lewisii

Some other good California native shrubs for erosion control are Western redbud, mountain mahogany, Western mock orange, lemonade berry, toyon, bush poppy, matilija poppy. spicebush, pink flowering currant and Western elderberry.

Smaller natives that put down deep roots are yarrow, coast aster, California fuchsia, wild grape, mimulus, buckwheat, wild rose, sage, deer and needle grass, Pacific Coast iris, penstemon, artemisia and salvia.

Remember when setting plants on a steep slope to arrange them in staggered

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California fuchsia

rows. Make an individual terrace for each plant and create a basin or low spot behind each one ( not around the stem ) to catch water. Set the crowns of the plants high so they won’t become saturated and rot after watering and make sure mulch does not build up around the stem.

These suggestions are just a few of the plants that control erosion. Every area is different and every situation unique.

Stars of the Fall Garden

More and more of us are embracing the concept of gardening with a sense of place. To garden where you live means accepting that your garden in California is naturally more subdued by fall. Plants that bring color to the garden at this time of year are invaluable. A successful garden is a feeling.

The fall bloomers and ornamental grasses are at their peak right now and thanks to our recent rainfall they are getting a big drink. Many birds are loading up on carbohydrates and fats to provide fuel for their migration. Others will stick around and want to be in the best possible condition for the winter season. In addition to seeds, nuts and acorns, flowers are important in their diets,

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Lion’s Tail

With Halloween almost upon us orange blooming plants like Lion?s Tail look perfect in the autumn garden and gets the attention of birds, bees and butterflies. The scientific name leonotis leonurus translates from the Greek words meaning lion and ear in reference to the resemblance of the flower to a lion?s ear but this perennial shrub has long been called Lion?s Tail in California. A member of the mint family it starts blooming in very early summer and continues through fall. Having very low water needs and hardy down to 20 degrees it?s perfect for a drought tolerant garden.

California fuchsia is also at the height of its blooming season. Starting in the summer and flowering through fall this California native will be covered with orange or scarlet-orange flowers that attract hummingbirds like crazy. A great plant along the path or draping over a rock wall this perennial thrives in areas that might fry other plants. Also known as Epilobium canan or Zauschneria it is in the evening primrose family and native to dry slopes and chaparral especially in California.

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Orange Stalked Bulbine

Another good choice for your drought tolerant garden is the long blooming Hallmark bulbine. The Orange Stalked bulbine is a succulent you?ve got to try. Starting in late spring and continuing through fall and often into winter this one foot tall groundcover spreads to four or five feet wide. The orange star-like flowers with frilly yellow stamens form atop long stalks that rise above the foliage. Remove spent flower stalks to encourage reblooming.

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Mimulus Jelly Bean Gold

What?s a fall garden without an orange or gold hued mimulus to feed the hummingbirds? Mine haven?t stopped blooming since early summer. Deer resistant and drought tolerant Sticky Monkey flower get the sticky part of their common name from their leaves which are covered with a resinous oil discouraging the larvae of the checkerspot butterfly from dining too greedily.

Orange and blue are opposite on the color wheel so they look fabulous together. Enter the salvias with their mostly blue and purple flowers. From California natives such as salvia clevelandii to Mexican bush sage to Autumn sage there are thousands of varieties on the market. All are deer resistant, gopher resistant, drought tolerant and hummingbird magnets.

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