Lake Cunningham Native Garden

Mulching with woodchips is a great way to control weeds, retain soil moisture, keep plant roots cool, and add slow-release organic nutrients to the soil. To be effective for several years (in a low-maintenance garden), the mulch should be at least 4″ deep. If you have paths at the same level as the beds, the thick mulching can make each bed look higher than the path. At the edge of each mulched bed, gravity and ground feeding birds (scratchers) will conspire to cause the chips to slowly bleed into the paths as well. How can you keep the woodchips in the beds where they belong and yet not fall on to the paths in the garden?

It is really simple, say landscape professionals who do this for a living. Say your path is made of hard material like flagstone or concrete. Before applying mulch, first dig a shallow trench all around the bed; the trench should be as deep as the thickness of mulch you want to apply. The cross-section of the trench should be an inverted saw-tooth: nearly vertical near the path, and sloping up gently on the other side to the level of the bed.

Now apply mulch all over the bed, including the trench. The mulch will give the appearance of raising the bed by the depth of the mulch, and gently slope towards the level of the path. Walk on the chips near the edge to make sure it is packed well.

Today we got to practice edge mulching in the bed with the “NATIVE GARDEN” sign. This bed is adjacent to Park Road, and a 6″ tall concrete curb separates the bed from the asphalt. The bed is at the height of the top of the curb. So when we lay a thick layer of woodchips on the bed, it has a tendency to spill over the curb and onto the asphalt.

To solve this problem, we began by digging a 6″ deep trench all along the curb. We saw-toothed the trench, so it was sharp at the curb, and sloped upward to bed level.

Step 1: Dig trench

Step 2: Fill trench with woodchips

We then filled the trench with woodchips, packing them tightly by walking on them, and grading it gradually towards the bed.

If our efforts are successful, the road should remain free of woodchips, and the edge of the bed should be free of weeds for many years.

View of the mulched bed from the accessible path

This weekend brought the first major storm of the season to the Bay Area. It rained off and on all day Saturday and Sunday. Despite the drizzle and the rain, volunteers from Foothill College, West Valley College, and Milpitas High showed up on Sunday to help out. Job one was loading and spreading a thick mulch layer in the bed facing Park Road and rearranging the logs to make them more visible. It was quite a workout. After a short rehydration break, we switched gears to remove invasive grasses at the base of a young coast live oak and several coyote bushes; below them we spread a thinner mulch layer to keep the weeds out and let the water through. We pruned up the coyote bushes to improve visibility and make it easier to work near them. The rain didn’t discourage the wildlife: we spotted a fence lizard, many Anna’s hummingbirds near the California fuchsia, and a scrub jay on the blue elderberry.

Mulched bed in the Native Garden at Lake Cunningham Park

Although summer has yielded to fall, the Loma Prieta fire still raging in the Santa Cruz Mountains is a reminder that fire season is not yet over. Fire, an integral part of California’s ecology, can still wreak havoc after decades of fire suppression and periods of prolonged drought. Once upon a time, native Californians routinely set small fires to clear out low growing vegetation without harming larger shrubs and trees. They knew that without periodic small fires, they would eventually be faced with a catastrophic crown fire that would consume everything, small and large. Their land management practices thus created the magnificent estate-like landscapes the Spanish encountered when they first came upon this land: vast meadows of bunchgrasses, annuals, and perennials interspersed with giant valley oaks that resembled the finest country gardens of Europe’s upper classes.

Within the comparatively short span of 250 years, California’s open spaces have now been overrun by invasive non-native annual grasses from Europe. These invaders live fast and die young; by early summer they have scattered a prolific amount of seed. Their dry stalks persist, however, and act as kindling for today’s fires, usually the first to ignite. Reducing and removing these invasive non-native grasses can diminish the fire risk.

In Lake Cunningham Park, the fire risk is low — Fire Station #21 is just one block from the White Road entrance — but we remove these invasive plants for another reason: they out-compete young native plants. We spread arbor mulch (woodchips) thickly over open areas to control weeds, to retain soil moisture, and to slowly enrich the clay soil with organic material.

An enthusiastic and effective crew from Silicon Valley Volunteers joined us today to mulch a large area between Park Road, the accessible path, and the parking lot. Volunteers worked efficiently to load the chips into wheelbarrows and bring them to the beds where they were spread evenly around the native plants. We weeded around each existing native plant so it was prepped for the rains with maximum exposure to sunlight.

The California fuchsia was in full bloom, and two resident Anna’s hummingbirds were squabbling over it. The toyon berries were reddening but not fully ripe. A Monarch butterfly wafted by while two dragonflies flew in formation. The day was mild and sunny, making it a joy to be out in the open, to exert ourselves without overheating.

Blue elderberry (above) and Bee’s Bliss sage (below)

Male Mallard

View additional photos posted by Silicon Valley Volunteers here.

Stay tuned for the 1st Day of Summer bird+plant ID walk in June.

This wet year has brought much needed moisture to California. The native plants love the moisture; so do the invasive plants. In particular, the park has invasive grasses from the Avena, Bromus, Loleum, and Hordeum genera. These sun-loving grasses germinate with the onset of rains, grow to form a thick carpet, and choke out the slower growing native seedlings. They seed prolifically before drying up and dying in late spring.

One of the most effective ways to control these invasive annuals is to smother them with a layer of woodchips. This denies them sunlight without which they cannot grow. The chips, if laid 6-8″ thick, will last about 5 years before decomposing to form rich compost.

On Sunday, January 10, 2016, a team from Piedmont Hills High Red Cross Club helped us do just that. They mulched weedy grass areas near the parking lot entrance to the native garden. They worked on both sides of the accessible path, and when they were done, the weedy lawns had been covered up nicely.

This will help the native plants in the area get established; when they grow large enough to cast their own shade, they will need less help from us in controlling invasive annuals.

The invasive grasses on the left side of the path have been conquered

PHHS Red Cross Club members

Native Garden entrance

Thanks to all for a terrific workday.

Saturday, January 2, 2016, was a cold, winter day in San Jose. It was cloudy but dry, the air was still, the temperature outside a chilly 41°F. In spite of that, a record number of volunteers showed up for the native garden workday.

Silicon Valley Volunteers consists of young men and women that volunteer their time for good causes. They have been to the native garden on two previous occasions, and this time they brought 12 volunteers. Together with 5 other volunteers, we made up a large team. Some were coming to the native garden for the first time, some had been here before, a handful were seasoned hands.

Silicon Valley Volunteers and others take a break

How does one get useful work done with a large and diverse group such as this? By planning ahead, dividing tasks into manageable chunks, and training.

We needed to plant 15 deergrass in a new bed that runs alongside Park Road. This is a new part of the garden in which interconnected paths will define new beds. We divided ourselves into 4 teams: diggers, planters, mulchers, and waterers. The diggers dug the holes. The planters then planted the deergrass into each hole, filling it up and tamping the soil in place. The mulchers encircled each plant with a layer of woodchips to protect the plants from their invasive neighbors. Finally, the waterers deep-watered each plant. We thought it would take us all morning to complete this task — we were finished by 10:30am!

Newly planted deergrass are barely visible amidst the mulch; in a couple of years, their dramatic stalks will be a commanding presence along Park Road.

After a short break to rest and hydrate, we mulched the bed across from the picnic area. The volunteers worked very efficiently, and both mulch piles were completely used up. On a tour of the garden, we learned about three common workhorse plants of the garden: coyote bush, blue elderberry, and toyon.

Members of Silicon Valley Volunteers expressed their shared interest in working outdoors and doing something for the environment. They want to adopt this new part of the native garden. We look forward to a long and productive partnership.

Jim Adams of Granada Native Garden in Livermore joined us for the last hour. His blog contains many well-written and researched articles on native plants: http://granadanativegarden.org/

We saw many healthy seedlings of toyon and blue elderberry all along Park Road. Birds have been gorging on fruit in the native garden, perching on the trees along Park Road, and doing their thing (evacuating, say the doctors). The seeds on the ground have germinated and taken root even through the punishing drought of the last five years. They are thriving without any assistance. This is a good sign of a functioning ecosystem.

The warblers and hummingbirds flew overhead. Toyon berries were almost all gone, consumed by robins and finches. All was well in the garden.

A plan for expanding the Native Garden at Lake Cunningham Park has been submitted to park staff. Under this plan, the garden would expand to cover the remaining area between the Park Road and Inner Lake Path, from the dirt parking lot in the east to the picnic area in the west.

The requirements for the expanded garden are:

1. Improve nature-based recreation opportunities for visitors.
2. Create a low maintenance landscape (reduced need for mowing, watering, or pruning).
3. Maintain and enhance the views of the lake.
4. Provide benches for resting and observing.
5. Provide alternatives to the Park Road used by walkers and joggers. Provide convenient connector paths between the Park Road and Inner Lake Path.
6. Provide summer shade to park visitors and anglers.
7. Provide improved habitat for local fauna.
8. Reduce the invasive weed load in the park.
9. Execute a science-based plan to eradicate Russian knapweed (Acroptilon repens).

The proposed plan contains several new paths. Visitors will have the option of using these paths instead of — or as a way to get to/from — the Park Road and Inner Lake Path. The paths would allow people to get closer to the flora and fauna of the native garden.

A detailed planting plan is being prepared. If you have ideas or suggestions, please post here or email chhaprahiya@yahoo.com.