Chuck Ingels, Farm and Horticulture Advisor
UC Cooperative Extension, Sacramento County

Organic soil amendments are products that are mixed into soil for the overall purpose of benefitting plant growth and crop

Soil amendments improve coarse-textured (sandy) soils mainly by improving the water and nutrient holding capacity by the addition of organic matter. Fine-textured (clayey) soils are improved by creating larger soil pore spaces and improving soil aeration, which leads to better water infiltration and drainage.

Organic soil amendments contain plant nutrients, but most are not considered fertilizers because their nutrient content is often quite low, and because release of the nutrients to plant-available forms can take weeks, months, or longer depending on the product. The most important benefit of the organic matter additions is to provide an energy source for bacteria, fungi, and other microorganisms, as well as earthworms that live in the soil. These organisms create glues (polysaccharides) that hold soil particles together to create highly desirable soil aggregates. They also release plant-available nutrients as they die off.

From an environmental standpoint, using amendments from a local source can reduce fossil fuel use and air pollution compared to shipping products across the country. Consider producing compost at home, using well broken down local manure, or growing cover crops to add organic matter.

Soil Amendment Analyses (click on header to see amendment chart link)

In July 2012, UC Master Gardeners purchased nearly two dozen organic soil amendments, also known as soil conditioners, from several retail outlets in Sacramento County. Samples were bagged the next day and taken to Sunland Analytical Lab in Rancho Cordova, who provided a discount on our analyses in support of Harvest Day at the Fair Oaks Horticulture Center. A soil analysis panel was selected that included the following tests.

% N—percent total nitrogen. Products ranged from 0.7 to 2.1% N. There is no threshold for how much N should be in a product. More important is the C/N ratio.

C/N ratio—carbon-to-nitrogen ratio.  Ratios above about 30 (30% C to 1% N) result in nitrogen “tie-up” in the soil because soil microorganisms such as bacteria and fungi require both carbon and nitrogen in their diet. They feed on the carbon source (soil amendment) and extract nitrogen from the soil when the C/N ratio is over about 30.  This temporarily deprives plants of nitrogen until the microbes begin to die off which often takes about 2-3 weeks. With amendments below about 30, the amendment will readily begin to release its nitrogen to the soil. The lower the C/N ratio the faster the release.

pH—the measure of acidity or alkalinity of the amendment, with pH 7.0 being neutral. A pH of about 6.5 to 7.0 is ideal, but pH 5.0 to 8.0 may be acceptable depending on the pH of your soil. Low pH materials such as sphagnum peat moss are best for blueberries and some ornamentals such as azaleas and camellias, but there are questions about the sustainability of increased harvesting of peat bogs in Canada and the northern US.

% Organic Matter—the measure of carbon-based materials in the product. Ingredients other than organic matter may include soil, nutrients, and other inorganic particles. There is no threshold for % organic matter.

Conductivity—indicates the amount of salts present, also called electrical conductivity or EC. Many salts are essential for plant growth, but excess salts in soil may be detrimental to plant health, especially for seedlings, transplants, and salt-sensitive plants, and to soil microbes. The threshold of salts in amendments depends on many factors, especially the salinity of your soil and water. If you have soil or water with elevated salt content, use amendments with lower conductivity – about 3.0 or lower. In most of the Sacramento area, water is low in conductivity, so the threshold is higher – perhaps up to 10.0.

To see the Analyses of Selected Soil Amendments, go to:
ucanr.edu/sites/sacmg/Soil_Amendments/
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.

Content for this blog was taken from the UC ANR Pollen Nation Website.

When you look at a flower, how often do you consider the importance of these unsung heroes? Pollinators help produce

Bees, wasps, flies, butterflies, moths, beetles, birds and bats help plants reproduce by carrying pollen from one flower to another.

Right now, honey bee and other pollinator populations are being threatened by a number of factors including disease, mites, and loss of habitat and food sources.

Three-fourths of the world's flowering plants depend on pollinators, and those pollinators need your help!

• Have you seen bees and other pollinators in your own neighborhood?
• Are there flowering plants in your garden, park, school or community? 
• Did you know that many pollinators are essential for the production of most of the fruits and vegetables you eat every day?

If you answered no to any of the questions above, click here to see how you can help!

Things to Consider for your Garden:

1. A variety of plants will be ideal for providing diverse sources of nectar and pollen. Choose at least 20 different plant types, or fewer if the types of plants are highly attractive to pollinators. Don't forget that night-blooming flowers will support moths and bats.
2. Help pollinators find and use your garden by planting in clumps, rather than just single plants. Think about "landing zones."
3. Include plants native to your region. Natives are adapted to your local climate, soil and native pollinators. If you want to see some locals, plant some natives!
4. Overlap flowering times between seasons and use a wide variety of plants that bloom from early spring into late fall.Pollinators are in a constant search for new resources. Choosing plants with overlapping flowering times from February to October will allow bees and pollinators to continually forage in your garden.
5. Consider plant climate zones. Plant for success! A plant's native climate range is important in determining if it will be attractive to bees visiting your garden (and if your plant will grow well in your garden or not!).
6. Design a garden that has structure. The arrangement of plants in your garden will influence your ability to
   
   observe and enjoy pollinators. Plant the tallest plants in the back with the smaller ones in the front.
7. Plant in the sun. Bees prefer to visit flowers in the sun, so avoid planting your pollinator-attracting plants in the shadier parts of your garden.
8. Reduce or eliminate pesticide use in your landscape, or incorporate plants that attract beneficial insects for pest control. If you use pesticides, use them sparingly and responsibly. Pesticides can kill bad insects as well as beneficial insects like bees, ladybugs and other predators of garden pests.
9. Don't' forget about nesting bees! Not all bees have a hive. Make sure to leave some areas for bees to build their nests (either in bare ground or in prefabricated cavities in wood). It's ok to leave part of your garden un-mulched for ground-nesting insects to discover. 
10. Leave dead tree trunks and branches in your landscape for wood-nesting bees and beetles. By leaving dead trees, or at least an occasional dead limb, you provide essential nesting sites for native bees, but make sure these are not a safety hazard for people walking below. You can also build a bee condo by drilling holes of varying diameterabout 3 to 5 inches deep in a piece of scrap lumber mounted to a post or under eaves.
11. Provide clean water for pollinators with a shallow dish, bowl, or birdbath with half-submerged stones for perches. 
12. Create a damp salt lick for butterflies and bees. Use a dripping hose, drip irrigation line, or place your birdbath
    
    on bare soil to create a damp area. Mix a small bit of salt or wood ashes into the mud. 
13. Provide a hummingbird feeder and add to nectar resources. To make artificial nectar, use four parts water to one part table sugar. Never use artificial sweeteners, honey, or fruit juices. Place something red on the feeder. Clean your feeder with hot soapy water at least twice a week to keep it free of mold.

Squash bug

Squash bugs (Anasa tristis) are nasty pests of the cucurbit family; zucchini, cucumbers, squash and pumpkins. Adults (5/8 inch long) are dark brown or gray which keeps them camouflaged around plants. Adults and young nymphs, as they feed, inject a toxic substance that causes host plants to wilt. When feeding is severe, leaves become black and die back. This condition is often referred to as “anasa wilt” which closely resembles bacterial wilt, a true plant disease. They also stink when crushed, so be forewarned that drowning them in a container of soapy water is a good option.

I battled squash bugs for years by picking off overwintering adults and destroying their eggs when they showed up on my zucchini. I often had volunteer squash plants that I used as decoys to attract them and I would destroy the plant and the bugs. I did this for years and I usually lost the battle, but finally they met their Waterloo. I eliminated the overwintering adults before they could reproduce about 6 years ago. Since then, I have been free of squash bugs in my garden. I am fortunate that I don't have close neighbors growing squash as a nearby supply of recruits might have undone my efforts, but I am so glad not to have to deal with this serious pest anymore.

Other pests that we all deal with are slugs and snails. The brown garden snail, Cornu aspersum, is the nemesis of California gardeners. It was introduced from France during the 1850s for use as food. They do provide food for my chickens, but I'll take a pass. I don't know who brought them over, but likely someone with little knowledge of the ecological harm such introductions can do. Such is the case with myriad introductions. Starlings, Japanese beetles, various other insects in the USA and rabbits in Australia come to mind.

There are baits which help control snails and I have used both the metaldehyde bait which is not child or pet friendly and the iron phosphate bait which is safe to use around pets. However, four years ago I decided to remove snails by hand picking and I have been successful in reducing their numbers, but will likely never eliminate them.  I go out early in the morning, sometimes with a flashlight to do my snail hunting. The first year, 2012, I picked off 3,287 and in the following year, 3,747. In 2014, they were much harder to find and I only got 220. This year, I am at 230 and still counting. Since I reduced snail abundance, my iris leaves are unblemished.

Spotted cucumber beetle

This year we had a much warmer than average spring and there were few aphids on rose buds. It could be cause and effect, but it could have been other factors. Complex environmental factors can affect different life stages of populations. As gardeners we can be glad the aphids were not abundant on our roses, but last summer I had problems with aphids on cucumbers, zucchini and melons. The IPM website, http://www.ipm.ucdavis.edu/PMG/r116300711.html, lists information on cotton aphids (Aphis gossypii) that attack melons.

Unlike rose aphids, the cotton aphid thrives in hot weather. It can vector cucumber, zucchini yellow, and watermelon mosaic viruses, among others. These virus diseases may be more destructive than direct aphid feeding. Host weeds for this aphid include milkweed, jimsonweed, pigweeds, plantain, and field bindweed, so keeping these host weeds controlled may be helpful. If cotton aphids, which are difficult to control, will just not show up this year on my melons, cucumbers and zucchini, I will be one very happy gardener!

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.

Shady areas have proven to be one of the most challenging areas to grow plants in the water-wise garden. There are plenty

California native Spicebush grows well in full shade and little water

Plant adaptations to shade boil down to two things: maximized light-capturing abilities, and the efficient use of energy. This has resulted in physiological differences between shade-lovers and sun-lovers; it would be wise to take advantage of this in the garden, rather than to fight it. The extra challenge of dry shade makes it difficult, but not impossible, to have a beautiful landscape full of interesting textures and colors.

Within the shade community, there are varying degrees of tolerance. Plants requiring some sun to thrive but able to do well with partial days spent in the shade are called “shade tolerant.” These are plants you might find labelled “part shade”; providing 4-6 hours of sun will help them do their best. Plants labelled “full shade” are likely to be shade-loving (sciophilous), and might burn if exposed to more than a few hours of sun a day, especially in the afternoon.

Buckeye butterfly nectaring on Santa Barbara daisy

The following plants are recommended for their hardiness in our climate and ability to thrive on a few deep soakings a month once established. Those marked with an asterisk* provide forage for wildlife, either directly (pollen, nectar, nesting material), or indirectly (habitat for insects eaten by birds, etc).

Part shade (4-6 hours of sun)
Agapanthus (Agapanthus spp and hybrids)
*Bush anemone (Carpenteria californica)
*Chaparral currant (Ribes malvaceum)
*Common yarrow (Achillea millefolium)
*Douglas iris (Iris douglasiana)
*Hummingbird sage (Salvia spathacea)
*Idaho fescue (Festuca idahoensis)
*Rosy buckwheat (Eriogonum grande rubescens)
*Santa Barbara daisy (Erigeron karvinskianus)
*Seaside daisy (Erigeron glaucus)

Full shade (less than 4 hours of sun)
*Island alum root (Heuchera maxima)
*California pipevine (Aristolochia californica)

Our native Snowberry brightens shady areas with it graceful foliage.

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.