Master Gardener News Blog
By Nancy Hartwick UCCE Master Gardener
Gardeners are fundamentally dependent on the soil we use to grow plants. But how much do we know about the qualities and character of soil. And what can we do to improve the soil to fit our needs?
The principal components of soil are minerals, organic matter, air and water which together, provide nutrients and anchorage for plants. The proportions of these elements vary in different types of soil and can either make the soil fertile and useful for growing plants, or deficient as a medium for plant growth.
A soil profile is composed of layers in which the various rock materials are sorted by particle size. The topmost layer will have smaller particles of sand and humus typically extending to a depth of 3 to 6 feet. Humus is organic matter that results from the decomposition of plant and animal material. This is the area where most of the plant nutrients can be found and also where plant roots thrive. It is a very dynamic area because this is where our “partners” work, such as earthworms, nitrogen fixers, and other beneficial soil organisms.
Plant growth is strongly affected by soil structure because it affects the availability of moisture to plants. A soil with good structure will have good water infiltration, drainage, and aeration. Topsoil that has too much sand will not have good water retention. Topsoil with too much clay will have good water retention, but not good drainage. In both cases, the best recourse for gardeners is to add organic matter to the soil which will increase porosity and aeration while improving the availability of water to plant roots.
Organic matter still in the process of decomposing may be added as top mulch at any time. When active decomposition is occurring, nitrogen can volatilize and will not be available to the plants. This may cause plants to suffer a setback. If undecomposed organic materials are incorporated into the soil just before planting or during plant growth, it is best to add an inorganic nitrogen fertilizer to the soil that will be immediately available to the plants. In time, fertility and soil structure will improve along with the production of humus.
Arugula The Cheerful
By Andrea Peck
Arugula (Eruca sativa) goes by many names: rocket, rucola, rucoli, rugula, colewort, roquette. All good names for a wild, easy-to-grow salad green. In my yard it self-sows to the point that I have not needed to purchase seed in a few years. The weird thing is that restaurants make it out as so fancy. Mostly it is just expensive.
Arugula is part of the Brassicaceae family, the same as kale, cabbage and broccoli, so it too packs a wallop when it comes to vitamins and phytonutrients. I don't know about you, but I'd much rather eat arugula than kale. With its slightly spicy, peppery taste you are bound to crave a salad. And there really is no excuse if it grows like a weed just outside your back door.
Growing arugula is pretty straightforward. Plant at the beginning of spring if you live inland; if you are on the coast you can probably make a stab at growing it year round. Arugula can handle a bit of frost. As a cool season crop, it will bolt more quickly in warm weather—one way to deal with this is to keep the soil evenly moist. This plant adapts to a variety of soils, but like most vegetables, prefers well-composted soil with good drainage. Keep the pH around 6.0-6.8 for best results. It grows in sun and part shade. The flowers are edible, but make sure to leave a few to keep the progeny going.
Once you've got your hands on a seed packet, broadcast seed or plant it in ¼” deep rows. These greens like to get cozy, so you only need rows to be 4-5” apart. Soil temperature should hover around 40°F and 55°F in order for germination to take place. A little arugula should poke a bit of greenery up in 7-10 days. The most useful way to handle this plant is to pick leaves as needed and then let it flower and go to seed. Arugula spreads easily in a non-invasive sort of way.
Arugula that flowers is very pretty in the garden. Flowers are small and pinkish; the plant itself may reach heights of up to 2'—they sway in the garden and generally look cheery. Pests such as flea beetles will visit arugula from time to time, but generally this leafy beauty is able to grow unfettered by pest and disease alike.
It's such a likeable plant that I suppose you could keep it as an ornamental, but then that would be a waste of a good salad!
By Jackie Woods
An invasive weed is an unwanted plant (native or non-native) that is able to establish on many sites and grow quickly to the point of disrupting the well-being of valued plants in the same location. For most home gardeners, weeds are unwanted – period. In order to keep them out of the garden, there are a few management practices that can be put into place to keep weeds under control: identification, eradication and prevention.
A key factor in fighting the good fight against invasive weeds is to be able to identify them. We all know what's supposed to be in our gardens so when something pops up that wasn't put there on purpose, we wonder “what the heck is that?” A few invasive weeds common to the Central Coast are:
Black Mustard (Brassica nigra)
Purslane (Portulaca oleracea)
Cheese weed or mallow (Malva neglecta)
Russian thistle (Salsola iberica Sennen)
Filaree (Erodium cicutarium)
Sow thistle (Sonchus oleraceus)
Goat head or puncturevine (Tribulus terrestris)
Mare's tail or Horsetail (Conyza canadens)
Yellow star thistle (Centaurea solstitialis)
Eradication of invasive weeds includes manual and chemical methods. If weed chemical warfare is not part of your eradication arsenal, hand-pulling the invasive beasties, roots and all, is the most effective and efficient approach. The goal is to detect and pull out the invasive weed before it reproduces and spreads. There's nothing worse than having vetch get away from you – one minute it's a two-inch weed and the next it's three feet long covering everything in its path.
The best form of prevention is early detection. Being aware of common invasive weed species can only help a gardener formulate a better plan of attack against them. If total prevention is the goal, consideration may be given to using mulch or weed cloth in bare garden areas to deter weeds from moving in. Only watering where there are wanted plants can also help deter invasive weeds from growing.
To guard against invasive weeds moving in to your garden, know the common species, eradicate them before they reproduce, and have a prevention plan in place. Visit the UC IPM Weed Gallery for photos and more information - http://www.ipm.ucdavis.edu/PMG/weeds_intro.html
The Shadowy Ficus
By Andrea Peck
I have a shy plant. She slinks along the walls, admitting nothing. She doesn't seem to grow, but she remains green despite my general lack of effort. She is somewhat lopsided. I suppose I could alter that, but why really? She never comes up in discussions—I think the term wallflower probably applies. Dare I say her name? Ficus. Ficus benjamina.
Is she blushing? I can't tell. She's green.
I call her she because I once had a co-worker who began a morning conversation with an elaborate story about her move-out situation with a jilted boyfriend. As the story wound on, I found myself completely confused.
“Who's she?” I asked.
A relatively large number of she-scenarios were bouncing around my head. I was in my twenties. I wondered if it was impertinent to even ask, but luckily I did. Evidently the she in this story was her Ficus. She was a small slip of a girl. If I remember correctly the Ficus weighed in heavily in the tale because she lived upstairs with her ex-upstart and she and her Ficus had had a difficult time leaving. Ficus do not have walking boots, after all.
Aside from its general femininity, the Ficus is odd right down to its name. How many plants are regularly called by their Latin name, while the common name, weeping fig, is largely unknown? No matter its predilection for covert behavior, it is the type of plant that easily ends up in your home, invited or not. I have to admit, there is something about this plant that I can't put my finger on exactly--something intriguing about her windblown aspect and quiet persistence.
I'm not sure why, but it surprised me to find out that the Ficus is a tropical plant. It originates in the rainforests of Asia and Australia. The whole thing makes me shake my head. My plant in the rainforest? I just can't imagine large insects and panthers brushing by my Ficus. It just doesn't jive. Of course, I can hardly imagine my ancestors running amok hunting animals and creating fire, particularly when it comes to my own kids who require a lie-down at the sight of a hangnail. When you learn about the care of this plant, however, the tropical origins linger fog-like amongst the scenes. You just have to alter your attention.
Those of us who do not live in the rainforest tend to cultivate our Ficus plants indoors. Mine is in a big pot right near my front door, which I just found out could be the reason it is “defoliating.” This is not the same as exfoliation, by the way. It is more in the realm of ‘hair-loss' for plants. In other words, it is an unwelcome event. My plant was moved recently, in order to accommodate a fancy new dog bed and the fake Christmas tree. The only Ficus-friendly space left was next to the door. Of couse, Ficus does not like the door because this is where “drafts” come from. It makes sense when you think how temperate and sweaty the rainforest must be. A draft probably never occurs there.
Ficus appreciate warm temperatures. Again this harkens back to their wild roots. In fact, 70°F or higher is just about right. Prolonged temperatures below 60°F are not recommended for this plant. The Ficus requires bright, indirect light to flourish. Direct light will burn the plant, but lack of light is also problematic. So, find a space that is warm, draft-free and bright and cheery but not glaring. Chilly confines, cool drafts and lack of light may cause leaf loss. Think of it as her dropping her hankie in an effort to get your attention. She's not dying; you'll just need to rethink the situation.
Humidity is important to this plant. Increase ambient moisture around it by placing the plant on a tray with pebbles immersed in water or mist it regularly. At the same time, do not overwater. Keep tabs on water needs by touching the soil—if it is dry to the touch then water, otherwise wait.
Your girl needs nutrients, so apply a weak solution of all-purpose plant fertilizer once a month during the spring and summer months. During the fall and winter you can give her a break or fertilize every two months. Use your judgement.
The Ficus plant is a valuable ally when it comes to clean indoor air—particularly ridding your house of formaldehyde, toluene and xylene. Another neat thing about the Ficus is that it is an actual tree. Outside, the Ficus grows to imposing heights. Inside, she'll remain modest. I suppose that is her greatest appeal. Her reserved demeanor does not allow her to ask for special consideration—but, if you give her a mist here, a dose of fertilizer there, and the right temperature and light, she will clean the invisible muck in your air and add life to your home.
Next week, I'll discuss a new pest that seems to have taken a liking to the Ficus.
Rain Catchment Workshop
By Andrea Peck UCCE Master Gardener
While El Niño packs its bags and readies itself for a busy season along the Central Coast, it's an ideal time for local residents to beef up their rain harvesting systems. We've been talking about saving water and reusing it for a while now, but if you haven't quite tamed your water ways or you'd like a refresher course, the University of California Master Gardeners are putting on an Advice to Grow By Workshop that is right up your rainspout.
Catchment systems come in many shapes and sizes, but all utilize naturally impermeable surfaces, such as rooftops, to collect rainwater. The water is directed into a container and then stored for later use. Amazingly, the average 1000-square-foot roof can potentially collect 600 gallons of water per 1-inch of rain. Even small catchment systems are beneficial in a multitude of ways. The advantage of rain catchment does not stop at water savings—harvesting those welcome drops reduces runoff, erosion and the spread of pollutants while utilizing a readily available resource.
Rain catchment systems range in complexity from a bucket placed under “that drippy spot” to cisterns with pumps and filtration that require extensive management. The workshop will discuss the various types of catchment surfaces, such as rooftops, along with distribution methods, such as downspouts and gutters. Storage tanks, size, material, expense and placement will be addressed. The presenters will tackle the “how” of getting your water to your landscape and discuss the finer points of water harvesting including purification, filtration, roof washers, and leaf screens. The group will focus on methods that promote easy upkeep, maintenance, health and safety. Information regarding “water catchment rebates” will be available.
Prepare for a showing of weather. Bring sunscreen, a comfortable chair, water and a hat. Who knows, maybe an umbrella, rubber boots and a kayak will be necessary. The workshop takes place Saturday from 10:00 a.m. to noon in the Garden of the Seven Sisters, located at 2156 Sierra Way, San Luis Obispo.