Category Archives: erosion control

Bonny Doon Ecological Reserve

Recently I went to the moon. At least it seemed like it. Walking through a portion of the 600 acres of burned out  vegetation from the , I couldn’t help but think of it as a moonscape. The misty fog was lifting after a night of rain and milky sun warmed us as we walked through the burned out trees. It was surreal and made even more so by nature’s valiant effort to regrow and fill the void left by the fire. At ground level the earth was bursting with life. Every inch of sandy soil was growing or sprouting something alive. You could almost hear it if you listened closely.

The fire destroyed 3 homes and severely damaged another. About 60% of the Bonny Doon Ecological Reserve burned. It’s amazing to see the recovery already taking place. The bracken ferns came first, followed by the endangered Bonny Doon manzanita some of which have sprouted from their bases while 6" tall starts from seed are everywhere. The burned gnarled trunks rendered the landscape otherworldly and magical. Pockets of manzanitas that were spared by the fire were in full bloom dripping with clusters of delicate, white urn-shaped flowers. This manzanita is endemic to the Santa Cruz sandhills and does not occur anywhere else on the planet. Did you know that manzanita leaves are still used in Russia in the tanning industry due to their high tannic acid content?

Golden chinquapin sprouted from the bottom of their mother tree and around the base are scattered the burr-like spiny bracts that contained a sweet tasting nut. California broom, so unlike the invasive Scotch broom, blanket the ground. They are one of the first plants to colonize an area after a fire and their quick growth can aid in erosion control as well as soil enrichment, through their relationship with the nitrogen producing bacteria, Rhizobium, in their roots.

Large stands of Bush poppies were growing in between the huge manzanita trunks. Bush poppies are common in sandy or rocky soils, often in burned out areas. These plants were taller than I’ve seen elsewhere in this area reaching 4-5 ft  Come spring they are going to be spectacular when they bloom in April-July but they also flower a bit in all seasons.

Silver-leafed lupine were doing their part to help the soil both by stabilizing with their deep roots and building up the nitrogen supply with the bacteria in its root nodules. Warty-Leaved ceanothus grew in large patches and were getting ready to bloom with their deep purple flowers.

Yerba santa were plentiful being an opportunist in the area and finding lots of open areas. They easily sprout from  from the roots after the fire as well as seeding themselves.

This area is a fire ecology and will come back just fine. It’s an extraordinary maritime chaparral habitat with a dense concentration of unique endemics that have emerged here in response to tens of thousands of years of periodic fires.

 

Groundcover Tips for Fall

The autumnal equinox happened this week. It’s the official start of fall when the sun crosses the celestial equator and moves southward. The earth’s axis of rotation is perpendicular to the line connecting the centers of the earth and the sun on this day. Many people believe that the earth experiences 12 hours each of day and night on the equinox. However, this is not exactly the case.

During the equinox, the length is nearly equal but not entirely because the day is slightly longer in places that are further away from the equator ( like where we live ). Also the sun takes longer to rise and set in these locations as it does not set straight down but in a horizontal direction.

Take advantage of fall planting weather by looking at what’s covering your ground. Be it the small lawn for the kids to play on, ground cover to keep the weeds at bay or erosion control to keep the hillside intact, this is an excellent time to plan for winter.

Let’s start with the lawn. If you still need a space for recreation, this is a good time to reseed those bare spots. Also to keep the lawn healthy, remove underlying thatch with a thatching rake. Then aerate the lawn by poking holes in the sod and fertilize with a complete lawn fertilizer like an organic all-purpose. Your lawn needs the phosphorus in the fall to encourage deep, strong roots for the winter.

If the kids are grown and no one is using that lawn, why not rip out the water guzzling grass and replace it with a walk-on groundcover? There are many to choose from like dymondia, lippia, potentilla duchesnea strawberry and several kinds of thyme.

One of my favorites is Elfin thyme. It doesn’t need mowing, edging or fertilizing or much irrigation. You can walk on it and it stays green all winter, shading into bronze tones when the weather cools. It even blooms in midsummer for several weeks. Bees will be attracted to it at this time. Thyme prefers sun and poor, sandy soil. Autumn is the best time to install from flats cut into 4" plugs planted about a foot apart. It will fill in within 3 years. Plant them closer together if you’re impatient. You’ll love your new lavender-blooming "lawn".

There are also Ca. native and prairie meadow grasses that you can walk on. They need little irrigation and even less mowing. Some can be planted from seed, others from plugs or sod. Good choices include Idaho, Calif. and red fescue, carex pansa, June grass and Hall’s bentgrass.

If you don’t need to walk on your groundcover, low-growing shrubs that are good groundcovers are baccharis, ceanothus maritimus, cistus salviifolius, grevillea lanigera, creeping mahonia, rosemany prostratus, rubus, manzanita, creeping snowberry and ribes viburnifolium to name just a few.

It’s time to enjoy fall weather and cover that ground before winter.

Resilient Plants for Santa Cruz Gardeners

We all approach the new gardening season with enthusiasm and optimism. Then the rain come down hard and pelts your new plants into the ground, the nights turn cold again and some of the plants in your garden aren’t so happy anymore. That’s when you need some tried and true plants to star in your landscape no matter what Mother Nature throws at you.

I’m often asked to give suggestions for resilient plants for a problem spot. These plants may have beautiful foliage, bark and texture, too, and serve two purposes in the garden. They may have flowers for some of the year to provide nectar for butterflies and hummingbirds or berries to feed wildlife. Most of all they are easy to care for and trouble free.

Snowberry gets an A+ for all of these qualities. A California native of shaded, mixed evergreen and oak woodlands, this 3-6 ft shrub thrives in a variety of locations including the dry shade under large trees like oaks. It tolerates poor soil and neglect and will grow well in full shade but blooms better and produces more berries if it gets some sun. Clusters of pure white berries appear in late summer and early fall and last through much of the winter. In late spring or early summer, its pretty blue-green leaves provide a nice contrast to the tiny pink flowers which hummingbirds love. Bees produce a white honey from their nectar rich pollen.

They can be pruned as a nice hedge providing twiggy, dense shelter for wildlife.Because of their vigorous root system, they are useful to stabilize banks and slopes. Maintenance is easy- simply prune away some of the suckers every few years to keep it in check. If it gets too tall,  shear it back in late winter to keep compact. The berries are not the first choice for most birds but thrushes will eat them if there isn’t anything else available. Other wildlife will eat the berries, too.

Lewis and Clark collected this plant and brought it back to Thomas Jefferson. It was sent to England in 1817 and became a popular garden novelty among plant collectors there.

If showy flowers are what you’re looking for in a specific spot, the perennial Phygelius would make a nice addition to your garden. This large 3-4 ft plant blooms from early spring into fall and you can grow them in full sun or light shade. Related to snapdragons and penstemon, the flowers also suggest fuchsias which is where they get their common name, Cape Fuchsia. Coral Princess is one of my favorites with lots of tubular, soft salmon and yellow flowers which attract hummingbirds.

In the same bed you might plant a few to fill and and add a nice contrast at the base of the Cape Fuchsias. This bright bluish-pink true geranium groundcover grows 8" tall and spreads slowly but widely. Easy to care for true geraniums are hardy in the winter, need just average watering and can be sheared each fall for fresh spring flowers.
 

Planning for Extreme Weather

Drought one year,  rainy the next.  How do you plan for these weather events in your garden?

CLIMATE-PROOFING used to mean tossing a little mulch on the garden, hauling pots of tender plants indoors or under an overhang.   But global warming and cyclical climate change has caused weather to grow so volatile that these traditional practices just don’t cut it anymore. Our gardens need year-’round help to deal with the new weather realities, including increasingly rain events in the winter and dry springs and of course our usual dry summers. . If you doubt the significant effects of climate change on our gardens, think about all the plants you consider hardy that may have died off in a really cold spell or the usually drought tolerant plants that didn’t like our dry spring last year.   The list varies by microclimate, but might include escallonia, abutilon, verbenas, Melianthus major, phormium and yuccas. Have you noticed birds returning earlier in the spring and lilacs blooming two weeks ahead of when they flowered 30 years ago?

We need a fresh arsenal of garden strategies, and it will help if we better understand the changing weather where we live and garden.  Our climate is influenced by the Santa Cruz mountain range and moderated by the Pacific Ocean.  Sixty inches of rain is "normal" for us but it’s been a few years since we’ve had this much.  While there is great year-to-year variability in our weather,  we need to be prepared for the worse case scenario.  You can lose both precious plants and trees as well as all the money and work you put into the garden.

How to deal?

• Begin by choosing tough, sturdy, self-reliant plants that need less water and fertilizer. Healthy plants are naturally resistant to pests and diseases when put in the sun/shade/water situations that suit them.

Compost-enriched soil provides the foundation for thriving plants that are more resilient to disease, drought or insect damage. Healthy soil absorbs water like a sponge and also stores carbon from the atmosphere, helping reduce greenhouse gases.

Reduce water consumption by using drought-tolerant and native plants, and by grouping plants with like water needs. Water with drip systems or soaker hoses; use tools like watering bags to keep new trees healthy. Remember to check whether your soil is dry before irrigating, and make sure you are watering more than just the surface.

Weed regularly so you aren’t wasting water on nuisance plants. To keep weeds down and water in, mulch garden beds at least once a year in late winter.

Global warming is creating what climatologists call "heavier rainfall events." This means more runoff and more stormwater problems. We can help by avoiding chemical fertilizers, pesticides and herbicides, and using porous surfaces like pebbles, gravel or pavers for patios and driveways rather than solid concrete. Install rain barrels and cisterns to capture rainwater to use for irrigation. Consider taking advantage of low-lying or boggy spots in your garden to create a rain garden, planted with moisture-loving natives, to slow down the passage of rainwater through the soil.

• Nurture the birds, bees and insects in your garden that are also confused by climate change. Make your garden a healthy habitat for all living things by eschewing chemicals. Plant a diverse array of flora that blooms early and late to encourage pollinators. Add natives and plenty of berried plants to feed and attract creatures.

• And finally, a few ideas on saving energy: Solar garden lights are the smart way to go; cut energy use on other outdoor lights by putting them on a timer. If you aren’t yet lawn-free, at least get rid of your gas mower, blower and weed eater, and use rakes and hand clippers; you’ll be rewarded with blessed quiet as well as energy efficiencies. You might consider arbors and pergolas for shade in summer and rain protection in winter. And it might not be a bad idea to invest in a rain barrel.

Put your Garden to Bed

 There’s a peaceful quality to this time of year.  Mother Nature is winding down for the season turning deciduous trees ablaze with fall color.  Cool season pansies and violas turn their little faces to catch the sun.  It’s time to put the garden to bed for a greener spring next year. 

 Here are some suggestions, but promise you won’t try to do everything on one weekend.  it’ll just seem like work.  Gardening should be something you enjoy. 

  • Build up your soil by layering the vegetable beds with 2" of leaves newly fallen from your trees.  Soil building worms and organisms will start their work right away.  In the spring, dig what’s left into the soil.  If you want the leaves to break down faster, run over them with a lawn mower, then rake them up for mulch.
  •  Prevent erosion of your precious soil by mulching with straw or bark.  Mulch used around perennials, shrubs and trees will help moisture percolate into the soil instead of running off into storm drains or creeks along with fertilizers.    Mulch also keeps the soil from becoming compacted by winter rains.  If you don’t have enough leaves to use as mulch try layering newspapers and cardboard and cover with straw.  3-4" of mulch around the base of trees and large shrubs will hold weeds down, too.  Be sure to keep mulch a couple of inches away from the base of your plants so trapped moisture doesn’t rot the trunk. 
  • Chop down leftover vegetable plants and spent annuals flowers and layer on the vegetable bed under cardboard to decompose.  Don’t do this with diseases plants such as squash plants with powdery mildew.   These can be put in the curbside yard waste can.  Hot commercial composting systems can kill disease spores.
  • Clean empty pots and store them upside down in a dry location.  That way you’ll keep any soil diseases from being passed on to next year’s plants. 
  •  Store any excess leaves to use next summer if you have a lot of deciduous trees.  They’re like gold.  They make great bedding for a worm bin and next summer you can use them in the compost pile when you have an abundance of nitrogen rich green material but little carbon-based brown stuff to mix with it. 
  • Leave a little debris for wildlife so beneficial ground beetles have a place to live and birds can snack on seeds left on shriveled flowers.  Coneflowers, ornamental grasses and crocosmia all attract birds to their seed heads through the winter. 

The bottom line is to do those fall clean-up jobs as you have the time and energy.  Cleaning up in increments leaves height and interest in the garden and feeds the birds, too.

What you should do first, though, is to bring indoors houseplants that  spent the summer out on the patio. Also bring in any plants too tender to survive the winter outside. Be sure to inspect them for insect pests and wash them off.   Sub-topical plants  like tree ferns and bananas benefit from extra mulch to help them survive the worst of the winter weather.

It’s not too late to reseed thin spots on your lawn or apply a fall fertilizer to an existing one and if you have citrus trees, rhododendrons, azaleas or camellias they’ll benefit from an application of   Citrus use it for flower bud development and fruit sweetness.  Rhodies, azaleas, and camellias need it when flower buds begin to form.  It also improves flowering and root development of any plant and helps plants resist diseases and cold weather damage. 
 

Erosion and You

 Now that we’ve had a bit of rain, it’s time to get serious about planting wildflowers for spring color and to attract bees,   cover crops to renew your soil,   and erosion control seed and plantings to hold your slope during the winter rains.

 Let’s start with the fun stuff- wildflowers.  Picture your meadow or garden filled with beautiful wildflowers, attracting all sorts of songbirds, hummingbirds, dragonflies and other beneficial insects.  If this is your goal, first get rid of existing weed seeds that in the soil and can smother out the slower growing wildflowers. The rains earlier this month will have germinated those pesky weed seeds so you can hoe them off now.  Be careful not to cultivate over 1" deep or you will bring more weed seeds to the surface.

Next, choose a site with at least a half day of sun.  Rake the soil lightly and spread the seed at the recommended rate.  It helps to mix the tiny seeds with 4 times as much sand or vermiculite so you don’t spread the seed too thickly.  Rake the seed very lightly into the soil and tamp it down for good soil contact.  Then you can wait for the next rain or water the area by hand.  It’s important to remember that after your wildflowers have germinated they must remain moist.  If mother nature doesn’t cooperate , you will need to hand water a for a while- a small price to pay for all that beauty in the spring.

What’s a cover crop?  These are grasses or legumes that grow during the fall and winter and then are tilled into the soil in the spring.  They help prevent erosion when planted on slopes and energize the soil when planted in the garden.   Preserve you topsoil and nutrients by planting a pretty cover crop like crimson clover. 

Crimson cloverCrimson clover has beautiful magenta glowers, but its primary benefit happens below the ground- the soil gains nitrogen, a better structure and greater biological activity.  Growing a legume, like clover, will "fix" nitrogen in the soil.  You can reduce the amount of fertilizer you use in the spring by 1/3 to 1/2,  especially in areas like the vegetable garden that need a lot of nutrients to produce all those good things to eat.   If you’re going to be growing peas or beans as the garden’s next crop, though, don’t use a legume cover crop in these areas.  You may end up with all vine and no peas or beans to harvest.  Heavy feeders like corn or squash will really respond to the extra nitrogen.

How do they do this?  Legumes attract soil dwelling bacteria that attach to the plant’s roots and pull atmospheric nitrogen out of the air and soil, storing it on the roots as nodules.  When the plant is cut down and chopped up to decompose in the garden bed, that nitrogen remains in the soil to feed the leafy growth of other plants.

 Besides reducing erosion a cover crop like crimson clover  can reduce soil compaction and their tap roots break up clay soil.
    To plant, rake the bed, sow the seed by hand and rake again.  Water to help germination if rains don’t do it for you.  Next spring, chop them down when they begin to flower.  Early spring is the best time to dig the clover into the soil because that dose of green manure is at it’s peak before the plant matures.  After a few weeks of decomposition, you energized soil is ready for vegetable seeds and starts. 

 Another way to prevent erosion is to plant native grasses, herbaceous and woody plants.  If you haven’t started planting a steep slope yet, you may need to use jute netting to stabilize the slope while the permanent plants are becoming established.  Santa Cruz erosion mix is a quick growing grass especially suited for our conditions.  You can also plant crimson clover under jute netting.

Whatever you choose, take steps now to prevent .