How we prep for planted areas at Mariposa
Minimize the weed pressure!
The Mariposa Team does it all for your garden; Design, Installation and Maintenance (or what we like to call 'Garden Care'). After the garden is in, we don't want our Garden Care team to be doing excessive weeding. So, over the years, we have perfected our approach to prepping your soil so that when our garden care team comes to care for your plants, the weed pressure is minimal. We do this through a series of steps, the first of which is to hand weed. In the garden we are featuring here, we did an initial weeding and then after about a week, when the crabgrass started to sprout again, we did an even deeper weeding to make sure we got as many of the roots out as possible. (Keep an eye on the red barn storage shed, this will help keep the perspective, as the garden changes).
How to mitigate a weedy "lawn"
When we arrived, the crabgrass and ehrharta were everywhere They were tall and well established. In addition, oxalis has infected many areas of the garden. We only noticed the oxalis after we had started our weeding this past October as oxalis only grows when temperatures are below 70 degrees. This can keep it hidden if we are designing a garden during the warmer months. However, once we start the clearing process, the tell tale bulblets will reveal themselves, so we know to take care of them too. When we initially come in and assess a new garden that is infected with weeds that are especially tenacious, we take note. We do not want to be dealing with them after the garden is finished. We want our clients to be happy with the results and to have a garden who's plants are thriving and not competing with the weeds. Crabgrass,ehrharta and oxalis are some of the most difficult weeds to deal with. Between the three, we had deep roots, easily spreading seeds and bulblets that can imbed themselves deeply into the soil and regrow quickly.
Once we remove all the weeds, we will flame weed. Flame weeding involves a special flame weeding torch that attaches to a typical grilling gas tank. The blue hot flame is quickly moved over the soil, effectively eliminating any existing weed seeds that are on top of the soil and desiccating any remaining roots that we may have missed. This is a very good way to prevent weeds from sprouting after we plant the new garden.
Its all about the cardboard!
At Mariposa, we believe in doing all that we can to protect the planet. One of the things that we do, which always feels like a win win is to lay down 2 layers of cardboard after the flame weeding is done. If we have discovered oxalis, we lay down 4 layers of cardboard. Cardboard is a great way to protect the soil and keep the weed pressure down. It is just enough of a barrier to discourage any weeds from coming up right after planting. However, it will decompose over a short period of time, allowing the soil to breathe. Typically, the plants we want to grow will have a bit of a head start with the cardboard in place suppressing the weeds. Once the cardboard breaks down, the desirable plants have filled in and the weeds are outcompeted. At Mariposa, one of our standards of practice is to collect cardboard that others are throwing away. One can purchase rolls of cardboard from box stores that sell building materials, but our aim is to make use of what is otherwise a waste source. We will find our cardboard in recycling bins, at the recycling center and our staff will bring cardboard from our own homes. If you have extra cardboard to discard of, please let us know! We will happily come pick it up and put it to use in one of our many gardens.
Another thing we do before we plant is to put in a grid of netafim irrigation. The netafim is a 1/2" line of irrigation tubing that has emitters spaced every 12." This allows the soil to be evenly saturated, like a damp sponge. When we keep the soil saturated at this level, every drop of water that hits the soil is wicked into it evenly. This level of saturation is good for nearly all plants, whether they prefer slightly drier or slightly moister soil. Even saturation keeps all plants healthy and thriving. Soil with even saturation is able to support a wide diversity of micro and macro organisms in the soil. Bioactivity in the soil keeps the soil healthy and your plants thriving. Our favorite place to purchase all of our irrigation supplies, including netafim, is Urban Farmer, a Bay Area legendary irrigation supply store.
Once the irrigation lines are all laid out, we add 3" of organic compost. Our favorite is a product called "Wondergrow." It can be purchased by the bag or by the yard from American Soil and Stone in Richmond, CA. The netafim lines are intended to be buried 3" under soil or compost. The beauty of this is that the water you are using to irrigate your garden does not evaporate the way it does with overhead sprayers.
As the drought lingers in California, and concerns about how to save water are at the forefront of our minds, many of us are thinking about how we can best conserve water in the garden.
Where do we get our water?
Water conservation is of utmost importance these days. Our rivers and lakes are depleted, and the water sources for our major cities and agricultural areas are running dry. But where does the water from our tap come from, and why is it running low? In the East Bay, our water supply comes from captured snowmelt from undeveloped public and private watershed lands of the Mokelumne River. It is collected at the Pardee Reservoir which is 90 miles east of the Bay Area.
“In a year of normal precipitation, EBMUD uses an average of 21 million gallons per day (MGD) of water from local watershed runoff.”
In drought years, most, if not all, of the snowmelt runoff is evaporating from the reservoir, so what we have historically counted on to replenish the water supply in the reservoir is disappearing. Without the annual replenishment of water to make up for what is used, the water stores become depleted. This is why there are alarm bells raised for us to conserve water in our homes by up to 30%. As the planet gets hotter and drier, our water stores are going to continue to diminish more over time.
There are many ways we can work together to bring down our water usage. Here are a few tips on how to save water in the home from the State Water Resources Control Board. Many of these tips, such as take 5 minute showers and turning off the water when you brush your teeth or shave can save a significant amount of water.
Even today, the overall square footage of most gardens are made up of a conventional lawn. Due to the high water usage of lawns, and because lawns are typically irrigated with sprayers that lose up to 75% of the water they put out in evaporation, they are water guzzlers, and need to go. One of the main ways our municipalities are asking us to conserve water is by restricting the amount of water we use in the garden. Currently, in the East Bay, we are limited to watering our gardens 3 times per week. For many of our established Mariposa Gardens, this works out fine. We have conditioned the soil, installed a Netafim drip irrigation system, a subterranean line that loses no water to evaporation. However, under watering a healthy native low use garden can have more damaging effects on climate change than it would cost to give that garden the right amount of water to thrive.
It's all about the soil
The Mariposa garden care team consistently checks the soil to make sure that the soils in our gardens have a very consistent saturation level to that of a wrung out sponge. When soils dry out due to heat spells, or after our long dry summers, they can become hydrophobic. Hydrophobic soils are like a dried out sponge. Water will be dripped into the soil and will bead off and roll down, not allowing its life giving sustenance to the plant roots. This can happen, even in an established garden under high heat conditions, especially on sunny and exposed slopes. Once the soils become hydrophobic, it takes a lot more water to rehydrate the soil so that it gets to the saturation point of a wrung out sponge. This saturation point in the soil acts just like a sponge does. It will take that drop of water, and wick it through the soil, thereby keeping your plant roots well hydrated. Well hydrated plants are healthier, are better able to resist disease and pests and also contribute to transpiration. It is the transpiration of plants that creates clouds, and rain. Therefore, we are under an ecological obligation to keep our gardens hydrated.
It’s important to understand that green, growing things (plants) provide a critical role in supporting the earth’s water cycle. Reducing water use by allowing our gardens to dry out and die back will only escalate our drought problems.
Transpiration is the movement of water through plant leaves, stems, and flowers into the atmosphere where moisture condenses and contributes to precipitation that falls from the sky and back into the soil. And then the cycle repeats. Less rain means less access to naturally clean water. And in the absence of a thriving layer of plants, any water captured in the soil moves further down into the ground, where it can be stored for thousands of years. Without plant cover, transpiration is reduced, in effect robbing the water cycle of potential moisture. A loss of green plants will increasingly heat up the planet and dry it out.
How do we Conserve Water?
At Mariposa, we have worked hard to find ways that we can both conserve water and keep our gardens lush and full of plant life that will contribute to the cooling of the planet. Sometimes this means that during hot spells, we may need to water our gardens in areas that are more exposed to the sun and heat more than 3 days per week. This does not mean the gardens need to over consume water, but allowing the soil to become hydrophobic is a bigger contributor to global warming than adding more water to the garden. We want to help our clients to find the balance between water conservation and keeping the gardens green.
One of the ways that we do this is through water harvesting. In all of our garden designs, we are incorporating ways to keep the water that falls on your property there. We will take your downspout and direct the water that falls onto the roof and slow it, sink it and spread it out into the garden. This helps to raise the groundwater table on your property, which can help larger plants such as trees and shrubs have better access to water during drought periods.
Another way we do this is by tapping into your graywater, and developing a greywater system that will keep your plants green. There are many ways to design a greywater system. One of our specialties at Mariposa is our Living Fountain. The Living Fountain cycles your graywater through a mini constructed wetland system. The water is filtered through plant roots and soil, nature's way of cleaning water, which is superior to any constructed water filtration systems. In addition to cleaning the water, it is also bio-activated with beneficial nutrients and bacteria which act to help your plants thrive, and become more drought tolerant.
Andrea Hurd, founder of Mariposa Gardening & Design.