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.

What’s in your Soil?

“The soil is made of butterfly wings, dinosaur teeth, pumpkin seeds, lizard skins, and fallen leaves.
  Put your hands in the soil and touch yesterday, and all that will be left of tomorrow shall return
  so that new life can celebrate this day.”  -Betty Peck

Soil makes all the difference to the plants you grow. The biggest issue we gardeners face is the ongoing battle with soil. If yours is difficult to manage or just plain unproductive you’ll be disappointed like me with the performance of many of the plants you put in the ground. Even tough plants like California natives have soil preferences and they are not always what’s in your garden.

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Low water-use plant responding to fertile soil

We live on ancient sea cliffs.  Soils in Bonny Doon and Scotts Valley consist of shallow, excessively drained weathered sandstone and shale. Felton soils were formed from shale, sandstone or mica schist. Those in Ben Lomond and Boulder Creek had their beginnings from weathered sandstone or granite. Although these provide the necessary mineral component of our soil. organic matter or humus from decayed plant and animal material are necessary also for fertility.

Here’s why improving your soil will make a difference to the health of your plants.

Good soil-with both organic matter and minerals-helps plants grow by forming the food supply for soil bacteria that help make food available for plant growth. Most of a plants energy goes to producing substances that drip out through the roots to attract bacteria and fungi. These in turn attract good nematodes and protozoa to the root zone. The protozoa eat bacteria and the nematodes eat not only the bacteria but also fungi and other nematodes to get carbon. What they don’t need they expel and this feeds the roots much like earthworm castings.

Down in the soil, if a plant needs different foods it can change what is secretes. Different substances will attract different bacteria, fungi, nematodes and protozoa. This huge diversity of soil biota helps the good guys keep the bad guys in check.

A common way to destroy the microbiology of the soil is to add salts in the

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Collection of perennials one year after planting in amended soil.

form or non-organic fertilizers. The salts kill the bacteria and fungi by dehydrating them. Then the plant can’t feed itself and becomes dependent on its fertilizer fix. Without the good bacteria and fungi in the soil other parts of the food chain start dying off as well.

The soil food web is also responsible for soil structure. Bacteria create slime that glue soil particles together. Fungi weave threads to create larger soil particles. Worms and insects distribute bacteria and fungal spores throughout the soil and create pathways for air and water.

What can you do to bring your soil back to life?
• Mulch around perennials, shrubs and trees with 2-3” of compost, wood chips or other organic mulch.
• Apply mycorrhizal fungi, especially in a new garden that’s been rototilled or chemically fertilized. You can find this in most organic fertilizers and some organic potting soils.
• Try to avoid walking on the root zone of plants. This kills fungi in the soil. Install stepping stones to preserve soil structure.

Feed your soil- not your plants.

Lessons in Water Conservation

There’s a saying that you should learn something new everyday and while visiting Robby Franks’ Scotts Valley garden recently I added valuable lessons to my irrigation know-how and successful succulent and other low water-use plant cultivation.

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Slope with dry creek bed, succulents and other low water-use plants.

You might remember a prior column of two about this “serial mole killer” as Robby laughingly described himself several years ago. He told me he’s licked his huge mole problem by exclusion and trapping plus he’s been the benefactor of a large gopher snake and a couple king snakes from the neighbors so he’s pretty confident now that his garden and all the work that goes into dividing and transplanting and mulching will not go in vain.

The soil in Robby’s garden is quite sandy and thin. He’s done wonders adding his own compost over the years. We all know mulching is one of the best ways to conserve water in the landscape. Robby has long been an advocate of composting and regularly renews the mulch in his garden. He even calls himself “Mr Mulch”. He has permeable paths and a dry river bed that allow rainwater runoff to soak into the soil slowly. He keeps his plants pruned in a naturalistic manner because “smaller plants use less water'”. But all this wasn’t enough. His 3 “dumb timers”, as he calls them, were using too much water. That’s when he started researching weather based smart irrigation timers.

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The dry creek bed

“To me it seemed like an easy way to conserve water and it’s better for the plants as well”, Robby said. “It will increase the irrigation times if the weather is hotter and dryer than usual, decrease it if colder and turn itself off if it rains”. After research Robby eventually chose the Rainbird ”Simple to Set” Smart Indoor/Outdoor Irrigation timer.

At a raised feeding platform a covey of quail were enjoying an afternoon snack. Below a group of Mexican marigold, fortnight lily, society garlic and euphorbia were thriving and Robby explained they are all watered with one irrigation hub called an Apollo 8 Port Bubbler. It is simple to install and screws onto an existing sprinkler riser or other 5/8” tubing. Each port can be adjusted to deliver just the right amount of water to each area. Attached a micro spray to the end of the 1/4” tubing and plants grow larger and deeper root systems.

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Collection of plants requiring little irrigation

Robby’s garden is a diverse collection of plants from all over the world. He told me he’s been impressed how the cordyline are growing and considers them better performers than the popular New Zealand phormium in both heat and cold conditions. But succulents are his passion. He’s got five varieties of sedum, three types of aloe including his favorite ‘Red Tip’, two varieties of sempervivum although he laments they are slower growing then he’d like, echeveria and his new favorite plant, Dyckia ‘Red Devil’. Although technically not a succulent but in the genus bromeliad it does have similar characteristics. “They remind me of an underwater scene”, he said. Their dark, spiky foliage did look a bit like giant sea anemone.

Robby does a lot a research and loves to share the knowledge he’s gained about plant cultivation and irrigation. Many a garden in Scotts Valley have benefited from his passion. Robby Frank is on a crusade to save water and Smart Irrigation and mulching is one way to do it.

Sheet Mulch Away that Old Lawn

Replacing that water guzzling lawn or dramatically reducing the size is a good place to start conserving water and is easier than you think. If you’ve been paralyzed with the thought of digging out and hauling away hundreds of square feet of heavy sod or using dangerous grass-killing chemicals, sheet mulching is the method for you.

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Sheet mulching in progress

This simple technique eliminates the lawn by smothering it with layers of compost and renewable materials. Here’s how to do it:

  1. Mow the lawn down to 1-2”, leave the clippings in place and soak with a hose.
  2. Flag the locations of sprinkler heads you will be keeping for your new plantings and cap off the ones you won’t need.
  3. Add an inch of compost to speed up the decay of the grass. If your lawn borders a driveway, path or sidewalk you’ll have to remove about 3” inches deep of soil along these edges and back 8-12” so that the new mulch doesn’t slide off into the sidewalk.
  4. Put down 2-3 layers of newspaper or one layer of cardboard overlapping the edges by 6-8” to prevent regrowth at the edges. You can buy recycled cardboard in rolls for larger projects or find your own at appliance or bicycle stores. Wet the cardboard or newspapers to keep them in place as you go along. It’s best to use cardboard or newspaper thatwill break down quicker. Don’t use plastic sheeting because water and air cannot penetrate it.
  5. Add a 3” layer of mulch such as bark chips from a tree trimming company. You can use compost, straw or shredded plant material. If you have Bermuda grass or other weeds like oxalis you will need to layer about 8” of mulch to smother them.
  6. Water thoroughly.
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Plants installed immediately after sheet mulching

If you can wait a month or more to let the decomposition process get going so much the better. If you just can’t wait you can begin planting now by scraping away the mulch and poking a hole in the cardboard or newspaper where the plant is to go. Then add some compost to help the new plant become established. Be sure to plant high enough to prevent crown rot and keep the mulch a couple inches away from the stem. The top of the root ball should be 1-2” above the soil and just below the mulch.

Modify the sprinkler to drip and remember to adjust your irrigation system run times to accommodate your new plantings.

This is a basic “lasagna” method for lawn removal. If you are planning to replant with water smart grasses you would choose finer composted mulch instead of bark chips. Either way the process works on the same concept as a compost pile. As the lawn dies from lack of light, it decomposes with the activity of beneficial worms, insects and microorganisms coming up from the soil and doing their job to break down the nitrogen and carbon in the sheet-mulch layers. It’s a win-win situation for the environment and your water bill.

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One year after lawn removal by sheet mulching

Water conservation starts with losing or reducing the thirsty traditional lawn and reducing irrigation. Transform your landscape into a resilient garden that not only saves water but acts to build the earth into a living sponge that harnesses rainwater and replenishes the aquifer at the same time. Attracting wildlife to your new beautiful garden is a bonus.

Be sure to apply for your rebates and have your lawn inspected, even if it’s dead, before you start.