Category Archives: Design trends

Controlling Erosion the Right Way

Native from California to Baja, Matilija poppy help stabilize soil and prevent erosion.

Not long ago I got a call from a home owner with a very bare, vary steep slope behind his house that was in dire need of some kind of erosion control and he needed it pronto. In the rebuild process after the fire the new building pad was created by cutting into an existing slope exposing a steep area with a retaining wall at the bottom. What to do?

I use to recommend Santa Cruz Erosion Mix but that is not the best solution and here’s why. According to the Resource Conservation District of Santa Cruz County, the California Native Plant Society, Weed Management of Santa Cruz County and Santa Cruz County Fish and Wildlife Advisory Commission, the mix contains non-native plants with very weedy attributes including: Blando brome, Hykon Rose Clover and Zorro Fescue. These weeds are rapidly spread by wind, water, animals, humans and equipment and once established are almost impossible to remove.

It’s important when you dealing with erosion issues that whatever you do now will not cause more problems in the future. Sometimes staying off the slope and doing nothing is the best thing to do.

Although native plants are great for long-term erosion control, they can take a few seasons to get established. These two sterile grasses that will germinate in winter, stabilize soil quickly and not become invasive: Common barley (Hordeum vulgare) and Sterile wheat.

Native grasses that grow deep root systems include:
* Meadow barley (Hordeum brachyantherum)
* Blue wild rye (Elymus glaucous)
* Creeping wild rye ( Leymus triticoides)
* Purple needle grass (Stipa pulchra)
* Nodding needle grass (Stipa cernua)
* California brome (Bromus carinatus)

There are many attractive plants that work well for erosion control. Often they need to adapt to shallow, poor soil and cope with less than ideal conditions all while putting down dense, strong roots. California natives are well suited to this job.

Common native shrubs include ceanothus and manzanita of all types. Calycanthus or Spicebush has fragrant flowers in late spring blooming well into summer with a spicy fragrance. The foliage is aromatic when crushed and changes from a spring green color to pale golden in autumn. Decorative woody fruits last into winter making this shrub attractive year round. It thrives with infrequent to moderate watering. Combine with coffeeberry and deer grass in sunnier spots or with Douglas iris and giant chain fern in shaded spots below trees. All these plants have deep roots and control erosion.

Ribes sanguinem or Flowering Currant is another show stopper capable of controlling erosion. In the spring the long, flower clusters of this deciduous shrub will dominate your garden. Choose from white flowering ‘White Icicle’ or ”Barrie Coate” and ‘King Edward VII’ with spectacular deep red flower clusters. ‘Spring Showers’ has 8 inch long pink clusters. Grow in full sun to partial shade. This California native requires little water once established and is a valuable nectar source for hummingbirds.

Some other good California native shrubs for erosion control are western redbud, mountain mahogany, western mock orange, lemonade berry, toyon, matilija poppy and western elderberry. ribes viburnifolium, creeping mahonia and baccharis. Ceanothus maritimus ‘Heart’s Desire’ and ‘Anchor Bay’ are all good ground cover selections and are not attractive to deer.

Symphoricarpos – Common Snowberry or Creeping Snowberry – can hold the soil on steep banks. This native tolerates poor soil, lower light and general neglect.

Smaller natives that put down deep roots are yarrow, coast aster, California fuchsia, wild grape, mimulus, buckwheat, wild rose, sage and salvia.

Bush poppy (dendromecon rigida) is another native found right here in our area and needs no irrigation at all once established. Beautiful bright yellow, poppy-like flowers cover the plant in spring. They can be propagated from cuttings taken in summer and are pest and disease free.

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

Fall is the perfect time to plant in our area. The soil is still warm encouraging root growth and the weather is mild. Using the right plants on hillsides can help slow and spread runoff and prevent soil erosion. Mulch also protects soil from direct rain impact and slows runoff across bare soils. Covering the steepest slopes with jute netting through which plants may be installed is an added precaution.

Japanese Maples in the Fall

Autumn Moon Japanese maple are breathtaking every season of the year.

I’m starting to see the beginning of fall color on some trees. It’s an exciting time of year. My friend, Kate, in Bonny Doon has an Autumn Moon Japanese maple that’s always in color, no matter the time of year. On a visit to her fabulous gardening in June this gorgeous small tree was a vision of burnt orange and bronze. I’m looking forward to seeing it when it turns vivid orange and red soon. What other Japanese Maples are my favorites for our area?

I have a Bloodgood Japanese maple that I love for the burgundy red foliage during the growing season turning to brilliant scarlet in fall. The interesting red-black bark provides interest in winter, too. This slender, upright tree is great for patios and entryways. It does well in sun also.

Another favorite Japanese maple is the Coral Bark (Sango Kaku) with the variety ‘Beni Kawa’ getting my highest marks. A cultivar originally developed in 1987, they are prized for their brilliant salmon red bark which is much brighter than the regular Coral Bark maple. The ‘Beni Kawa’ is a fast growing Japanese maple that will eventually reach 10-15 feet tall and 5-12 feet wide. It is hardy to 15 degrees. You can even polish the coral bark in the winter if you really want to see that beautiful bark.

There are so many awesome varieties available these days. From the variegated ‘Butterfly’ to ‘Oshio Beni’ with its crimson and orange fall color to ’Seiryu’, an upright lace-leaf variety with an upright habit that turns bright gold, yellow and crimson in the fall.

I see trees of all kinds going into an early dormancy showing a touch of fall color only. Every year is different.

Other things besides hot weather and not enough summer water to consider regarding fall coloring is that it can be disrupted by wind and rain coming at the wrong time. Japanese maples have a more delicate leaf than some of other trees and are more susceptible to the elements of nature. We most likely won’t get rain spoiling the display but wind during this time will put a quick end to the autumnal display.

Hakone Garden ‘Crimson Queen

Leaves change color when they are going into winter dormancy. When nights get long enough, leaves develop a corky layer of cells between the leaf stalk and the woody part of the tree. This slows the transport of water and carbohydrates. The manufacture of chlorophyll is slowed and the green color of the leaves begins to fade, allowing the other pigments to show through. Since the transport of water is slowed down, food manufactured by the remaining chlorophyll builds up in the sap of the leaf and other pigments are formed which cause the leaves to turn red or purple in color depending on the acidity of the sap.

For example, sumacs and California wild grape almost always turn red because red pigments are present and their leaf sap is acidic, While many of the oak and sometimes ashes will get a purplish color because the sap is less acidic. Trees like birch don’t have much orange pigment, so they appear mostly yellow in the fall. Others don’t have much yellow pigment and turn mostly orange or read. Some trees have a balance of pigments and look pinkish. The brown color or many oaks can be attributed to a buildup of tannins which is a waste product in the leaves.

So don’t miss out on Japanese maple season. You won’t regret getting a new one for your yard or patio.

Plant News You Can Use

A traditional apple like this Red Delicious might not fare as well in a warming climate.

A recent article in the New York Times caught my eye: Hot weather cherries, drought resistant melons and six other crops that are being developed or already in the market could change how we eat in a fast warming world. In the face of our erratic climate, floods and pests that farmers never used to worry about plant breeders are working to perfect varieties of fruit and vegetables that can thrive under these conditions. Solutions can come from research in molecular technology to mining the vast global collections of seeds that have been conserved for centuries. These new fruits and vegetables taste good, too. Here are just a few in the news.

In a warming climate, cherries are finding it harder to get enough chill hours during the winter and also handle hotter summers. Breeders have come up with the heart-shaped Cheery Cupid which handles these conditions and is also juicy and sweet. They will be available next season in North American markets.

Then there are two new melons – the Supermelon and Flavorific – with deeper root systems have been bred to handle drought my pulling more water from the soil. They can drink less. The melons are sweet, with dense flesh, and have just been made available to farmers.

If you like cauliflower there’s a new variety that won’t get sunburned in a warming climate. Now, farmers fold the leaves back over the white head or curd by hand about two weeks before harvest. It’s expensive and time consuming. Plant breeders developed the Destinica, a true white cauliflower. It’s already in supermarkets. Essentially, it doesn’t get sunburned and it’s easier on the soil because fewer workers walk the fields. The same developer has breed a white cabbage that requires less nitrogen and can thrive during prolonged dry periods.

Breeding a new apple takes time. A horticulturist at Washington State University, Kate Evans, says twenty years is typical. Cosmic Crisp, an apple developed to grow well in the heat now grows on 21 million trees in Washington State.

Another promising new apple is the Tutti, a light crisp red apple being tested throughout Europe. A New Zealand company developed it to help Spanish farmers struggling with hotter temperatures.

We all love avocados. A new, more environmentally friendly avocado has been 50 years in the making. The Luna, which is nutty, smooth and perhaps a bit sweeter than the Haas, was developed by breeders at the University of California, Riverside which houses one of the world’s largest collections of avocado genetic material. The new trees are slender, shorter and have a smaller footprint. They use less water and produce more fruit on less land. They are also easier to harvest which saves labor costs.

Enter the potato. Potatoes like a constant, moderate supply of water and prefer cool weather, but the climate is changing so fast that researchers recently warned that the potato industry is in trouble. Researchers at the University of Maine are looking to South America, where potato cultivation began around 8,000 B.C. and to heat tolerant varieties in the American South for genetic traits that can help spuds survive excessive heat and floods.

Researchers are also exploring how to battle new waves of pests and disease that come with hotter, wetter growing conditions. One strategy being studied is breeding plants with hairier leaves which make it harder to insects to move through crops.

These are just some of the vegetables and fruits in our future.