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MMWD Blog: Think Blue Marin

Welcome to our blog! Written by staff at MMWD, “Think Blue Marin” explores all things water in south and central Marin—water supplies, conservation, new projects, watershed management, and more.

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Feb 16

‘Tis the Season

Posted on February 16, 2018 at 10:01 AM by Ann Vallee

by Charlene Burgi

As I drove up the ranch road yesterday upon returning from my vacation in St. Lucia, I noted a hint of green poking up in the pastures. As I understand it, in my absence the temperatures warmed up, which along with damp soil made for the perfect recipe for weed growth. It is the season to nip these little invaders in the bud (no pun intended) before they take serious root. 

The question is how to proceed? Actually, there are five methods to mitigate weed growth: preventative, mechanical, biological, cultural and chemical. Different situations call for different techniques. And in some cases, you might need to combine a few of these five methods to successfully manage this ongoing chore. 
The easiest method to start eliminating weeds is prevention. Using clean topsoil, weed-free seeds and well-processed compost are great ways to prevent accidentally sowing weeds in your garden. If you use garden tools in a weedy area, clean them before moving on other parts of the garden. Adding a thick layer of mulch can also deprive weed seeds of the sunlight they need to germinate.

Mechanical methods include mowing, weed-eating or rototilling the existing weeds. Even the use of my new hori-hori tool would qualify as a mechanical/manual method of disturbing weed growth, as would hand-weeding. 

 Goat grazing on weeds in St. Lucia
Biological methods include an interesting range of approaches. While I was in St. Lucia, it was common to see goats, horses and cattle tied securely along roadsides as they grazed on the weeds. While this might be a bit extreme in Marin, we can utilize chickens that scratch the new sprouts to unearth them, or peck at the lush greenery springing up. Certain insects, pathogens, nematodes, fungi and bacteria can also be used to target weed problems. (The goat/horse/cow methods, while helpful, might require additional work as I am sure the manure from these animals carries weed seeds that, in time, will germinate!)

Cultural controls include garden management practices such as crop rotation, cover crops and the use of slow-growing vegetables such as cabbage that shade the soil and prevent weed growth. Adding lime to alter the pH of the soil to discourage weeds is another avenue employed. However, this gardener would require far more knowledge about the specific weed seeds present and the pH levels needed to offset their germination.

Lastly are the chemical means of eradicating weeds. These methods need not be harmful to the environment. For example, spraying white vinegar and dish soap will burn back the top growth of weeds before they take root. Plant oils such as orange oils can be used. Other organic methods employ boiling water or even salt. Still, be careful even with these organic methods as they are all non-selective killers. This means they may impact the root systems of nearby plants, thereby damaging wanted plants in the garden. 

Non-organic chemicals (herbicides) are also commonly used. However, these chemicals can leave residues or toxins in the soil that can be harmful, so it is important to do your research. Check to make certain the product is effective against the weeds you are targeting. For example, some herbicides only kill grasses, while others target broad-leaf plants. All chemicals carry MSDS labels providing important information. Before purchasing, read the labels. Look for the signal word indicating relative toxicity—that is, does it say “caution,” “warning” or “danger”? Are there crossbones or does it say “poison”? All herbicides are required to go through toxicity tests that determine their handling and usage.

As for this gardener—weeding has its rewards. As one website suggested, you can even eliminate weeds by eating them. Dandelion greens are supposed to be a delicacy. Bon appetit!

Feb 08

When Life Hands You Lemons

Posted on February 8, 2018 at 10:35 AM by Ann Vallee

by Charlene Burgi

The scuba-diving trip I’ve been planning for a year has found me in St. Lucia with ear infections and the inability to dive. What's a person to do? It didn't take long for this gardener to move to Plan B. 

 banana tree
 Banana tree in St Lucia
On this tropical island, ferns grow like trees and color abounds. “Vegetation is not lacking,” I thought, while eating lunch with friends at the resort where we are staying. The shrubbery next to me caught my eye when I noted an unusual shape growing within. Upon closer inspection, I realized the shape was very familiar, only hanging upside down from what you might expect ... bananas! Fruit trees are all around the resort. It then dawned on me we are in the midst of bare-root season at home. 

Bare-root season is a time to let your imagination run wild. There is no reason not to have fruit trees and assorted berries, asparagus, rhubarb, artichokes or grapes growing in our gardens. Even the smallest of garden spaces can support dwarf fruit trees grown in containers on your deck or patio. The only caveat for container gardening is the need for additional fertilizer and monitoring of water needs.

For me, bare-root season represents a time to explore nurseries for the huge selections not available during other times of the year. Many people are intimidated by purchasing a tree without a container. So, while my friends are off diving, let me share the simplicity of this planting process with you.

First, after selecting your tree(s) of choice, examine the exposed roots. Prune all broken roots back to healthy tissue. Fill a bucket with water (I usually add some vitamin B1 to the water) and let the roots hydrate overnight.

Pick a good sunny location to plant your new tree. Some fruits do better if located where they have some protection from the wind. 

Dig a generous hole and create a cone of soil in the middle to cup the roots around. Lay your shovel across the hole as a level, and set the tree in the hole. Note where the graft of the trunk of the tree sits in relation to the prostrate shovel. The graft should be about two inches above the shovel. Adjust the soil elevation accordingly before proceeding.

Once the soil level is adjusted and the tree positioned, begin adding prepared soil a bit at a time. Gently but firmly tamp the soil around the root system with the butt end of the shovel handle before adding more soil. Continue adding soil in this fashion until you are at grade, then water in well.
Next, check the top growth of the tree. Remove all broken or damaged branches as well as branches growing toward the inside of the tree. If two branches cross each other, remove the weaker. 

It may be a few years before you reap the benefits of your labor, but you’ll know your efforts were worthwhile the first time you bite into that sweet peach or plum and feel those juices flowing down your chin. 

As for lemons, citrus does not come in bare-root form, but Marin cannot be beat for growing citrus. And if you live in the most southern part of Marin, it might even be worth trying your hand at growing bananas.

Enjoy your surroundings no matter where life takes you! 
Jan 29

Lagunitas Creek Spawner Update: 1/29/18

Posted on January 29, 2018 at 9:48 AM by Emma Detwiler

Written by: Aquatic Ecologist Eric Ettlinger

January has been fairly typical in terms of salmonid activity in Lagunitas Creek. That’s a marked contrast to December, when it simply didn’t rain and very few salmon spawned, and November, when four salmon species were spawning. This month we’ve had three decent storms that allowed spawners to migrate into tributary streams, which has kept us busy conducting surveys all over the watershed. Over a four-day period we counted 155 coho salmon, which is a respectable peak spawning week. Since then our coho observations have dropped off while our steelhead observations have ramped up, which is also typical for this time of year.

But a few things have continued to be unusual. First, somewhere around half, maybe more, of the coho we’ve seen have been jacks. Jacks are small, two-year-old males that return to spawn after less than a year in the ocean. The last time we saw this many jacks was in 2002-03, which turned out to be a preview of the large coho run of 2003-04. Maybe this year’s jacks also predict good things for next year.

Not to be outdone, steelhead numbers are also unusually high. To date we’ve counted 33 steelhead, which doesn’t sound like a lot, but steelhead are easy to miss. They’re quite cryptic and spawn quickly. The last time we saw this many steelhead in January was 2008. That run ended up being one of the largest ever documented in Lagunitas Creek. Steelhead will continue to spawn through April, so we won’t know for a while if the run is one for the record books.
Steelhead male (large grey fish), female (large fish below male), and a coho jack at far right. A juvenile steelhead can also be seen below the female, trying to spawn with her.