- Author: Nadia Zane
This time of year finds us cleaning up the garden and throwing away the trimmings without ceremony or thought. This 
Defining waste is tricky, but you could think of it the same way as weeds, which are basically plants where you don't want them; like weed management, reducing garden waste comes down to re-thinking and altering your cultural practices:
Plan ahead: Shopping at a nursery without a plan is like going to the grocery store hungry; impulse buys are inevitable! Measure your space, research climate-appropriate plants, and call nurseries for availability. Try to favor evergreen (non-deciduous) species, limit herbaceous perennials and annuals, and provide all plants adequate space for their natural size and shape. Constant shearing is a waste of time, and planting too densely often means you are tearing out plants within a couple of years, a waste of the water and other resources that went into growing those plants.
Irrigate and fertilize appropriately to avoid the feedback loop of wasteful inputs: too much water and high N-P-K fertilizers create lush growth, which is more attractive to pests, requiring herbicides and more irrigation to keep up with all that growth. Potent fertilizers often leach below the root zone or out of the soil via irrigation run-off, polluting rivers and groundwater, and wasting your money. Organic fertilizers with low N-P-K numbers provide a slow release of nutrients, which can be taken up more effectively by soil microbes and plants.
Composting is the best way to recycle myriad forms of plant matter, both from your yard and the kitchen, into a source of bio-available nutrients. Compost also helps improve soil structure (a definite plus for those of plagued with adobe) and increases the biodiversity of your soil, a way of protecting your plants from pathogens.
Grasscycling: Recycling grass clippings by leaving them on the lawn reduces fertilizer needs by 20% and returns valuable organic matter to the soil. It's easier on your back, too! Problems associated with grasscycling often result from improper practices; see the resource section below for help.
Avoid invasive species: Some plants have aggressive growth and produce a lot of waste when they need trimming. Examples of invasive species include English ivy and Vinca major. Some invasives can re-root in a compost bin, so they end up in the landfill. for examples of invasive plants and alternatives, see the California Invasive Plant Council (Cal IPC) website.
Resources:
Fertilizing: sjmastergardeners.ucdavis.edu/files/154369.pdf
Composting and Grasscycling: sjmastergardeners.ucanr.edu/Composting_/
Cal IPC: www.cal-ipc.org/landscaping/dpp/
If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website.
- Author: Nadia Zane
A fragrant garden often draws us in to explore further and engage our other senses, 
Plants use one of two basic methods for storing essential oils. The first is on the surface of the leaf in hairy structures called glandular trichomes. These plants need only be brushed against to release their aroma, and are often quite fuzzy in texture. The second storage method utilizes specialized structures inside the leaf. These plants need to be crushed or bruised to release their aroma and may or may not be fuzzy (fuzz does not always mean a plant has essential oils).
One of the most fragrant plant families is the mint family (Lamiaceae). This group has glandular trichomes, so simply rubbing the foliage will give you nice whiff. Some hardy, water-wise perennials in the mint family include:
- Lavender (Lavandula spp): With fragrant flowers and foliage, it's hard to pass by lavender without stopping to appreciate the lovely aroma. There are plenty of varieties to choose from, but all prefer well-drained soil, which should be allowed to dry slightly between waterings to avoid the common problem of falling outwardfrom the middle.More information on lavender selection and care can be found at: anrcatalog.ucdavis.edu/pdf/8135.pdf
- Rosemary (Rosmarinus officinalis): A great culinary herb with evergreen foliage and pretty bluish flowers requiring little maintenance. A nice shrubby variety is ‘Mozart'; ‘Prostratus' is a low-growing variety for retaining walls.
- Sage (Salvia spp): Culinary sage (Salvia officinalis) is quite popular, but there are more drought-tolerant species to be had. Two intensely aromatic species are White sage (Salvia apiana) and Cleveland sage (Salvia clevelandii), which your nose will find from a great distance. More subtle are Autumn sage (Salvia greggii), Germander sage (Salvia chamaedryoides), and Hummingbird sage (Saliva spathacea).
- Other great water-wise plants in the mint family include Catmint (Nepeta x faasenii), Coyote mint (Monardella villosa), Pitcher sage (Lepechinia fragrans), andRussian sage (Perovskia atriplicifolia, not a true sage). Even more can be found at: ucanr.edu/sites/sacmg/files/196286.pdf
Plants that need to be bruised to release their fragrance are many; some good ones for the Central Valley include:
- Lavender cotton (Santolina chamaecyparissus): A bright, silvery plant with cute yellow buttons for flowers and frond-like foliage with an aromatic, pungent fragrance. Attractive to pollinators, low-growing, and appreciative of well-drained soil.
- Spice bush (Calycanthus occidentalis): A large, deciduous shrub with lovely red flowers in spring. The foliage emits a clean, spicy fragrance when crushed. Spicebush is less fussy about soil and summer water than some of the species listed here, but does OK in water-wise gardens as well with a few deep watering a month in the dry season.
- Yarrow (Achillea spp): Although the wild species is quite aggressive, the cultivars are better behaved, while still offering up a nice scent. Yarrow comes in many colors, from yellow-orange to pinkish lavenders and reds. Some of my favorites include Woolly yarrow (Achillea tomentosa), and the many cultivars of our native yarrow (Achillea millefolium), including ‘Island Pink', ‘Paprika, and 'Terracotta'.
Plants tend to go about their business, and the essential oils they produce may not be for our benefit alone, but their addition to the garden experience has endeared them to us. The lovely fragrances possible for the water-wise garden provide just one more reason to try them out!
If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website.
- Author: Nadia Zane
Of the many tools we use in the garden, one of the most effective multi-taskers is mulch. This water-saving,
Mulch, a material loosely defined as anything applied to the soil surface for protection and improvement, comes in two basic forms. Organic materials are carbon-based (i.e. used to be alive) and biodegradable. Nonorganic mulches are synthetics (e.g. plastic or rubber), or natural materials that decompose too slowly to benefit the soil in our lifetime (e.g. rocks). Organic mulches are generally considered to be the most beneficial for garden health, as they provide many services:
- Improved soil tilth: Tilth refers to how suitable the soil is for growing plants. Mulch provides both food and protection from Delta winds, the hot valley sun, and frosty winters for micro- and macro- organisms living in the soil. This stabilized environment allows them to go about their business, contributing nutrient availability, aeration, and soil structure.
- Erosion control: With better soil structure comes better water absorption. Mulch also slows heavy rains so water has a chance to percolate into the soil; in summer, mulched soils are less likely to form a crust, allowing for better percolation when irrigating.
- Weed control: Mulch prevents annual weeds from germinating by blocking sunlight from hitting the soil surface.
- Water conservation: Mulch helps retain soil moisture by reducing evaporation, which usually translates into reduced irrigation needs.
- Healthy roots: Fine roots are highly susceptible to drought stress and high temperatures; mulch helps keep the soil cool and hydrated, enhancing plant establishment and overall vigor. Healthy plants are more resistant to pest damage, requiring fewer chemicals and less maintenance.
The home gardener has many types of mulches to choose from; selecting the best for your situation depends on what and where it will be used, your budget, and availability. In beds where the ground will be worked every year (e.g. annual and vegetable beds), use short-lived materials such as straw or compost that can be incorporated into the soil if desired.
Long-lasting materials such as bark nuggets are best for perennial beds where a slow release of food over time is desired. Soil organisms use up nitrogen as they decompose the bark, so it should only be used on the surface to avoid nutrient deficiencies (nitrogen eventually returns to the soil as organisms die).
Synthetic mulches such as black plastic are good where warming the soil is desired (e.g. for vegetable beds) or to eradicate soil-born pathogens. However, it is not the best choice for perennial beds in the home garden. Plastic restricts air flow and water penetration, creates a mess as it breaks down, is not completely biodegradable, and weeds can grow through holes and tears. Drip irrigation must be used underneath, which can be difficult to inspect and maintain when covered with plastic sheets.
Gravel has more aesthetic appeal than plastic and lasts a long time. Some plants, such as succulents, are much better off with gravel mulch. However, a huge disadvantage is it's high thermal mass, meaning it absorbs and radiates a lot of heat. This might be a bonus in some parts of the world, but not in a sweltering city like Stockton. Although some gravel is fine, avoid graveling your entire landscape to keep your air conditioning bills and the city's heat index down.
Correctly applying mulch is just as important as knowing what kind to use. For ornamental perennial beds, a 3” – 4” layer of coarse bark or 2” of small bark is recommended. Keep mulch 6” away from trunks to prevent root rot. Mulching techniques for vegetables and annuals varies greatly, depending on the crop and type of mulch being used. Newspaper, straw and grass clippings are common and readily available; make sure the last two are weed-free to avoid a bed full of undesirables!
More information on mulches can be found at the following websites:
www.ext.colostate.edu/mg/gardennotes/245.html#trees
ucanr.edu/sites/UrbanHort/files/80212.pdf
No talk of mulch would be complete without a discussion of where not to use it. Besides the obvious impracticality of mulching “the back 40”, approximately 70% of North American native bees are solitary ground-nesters. If you have a well-drained, sunny spot (preferably on a slope), leave it open for our native bees, whose habitat is rapidly disappearing. For best results, avoid cultivating or walking on this sacred ground. See the Xerces Society webpage for more information:
www.xerces.org/providing-nest-sites-for-pollinators
If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website.
