Not all compost is created equal.
Chuck Ingels of the UC Cooperative Extension's Sacramento County office discovered what many gardeners suspected.
The results of that research will be part of the upcoming Harvest Day, set for next Saturday at the Fair Oaks Horticulture Center in Fair Oaks Park.
Billed as "Sacramento's ultimate gardening event," Harvest Day annually highlights the summer calendar for many. About 2,000 gardeners will turn out to the Fair Oaks Horticulture Center to pick up fresh ideas while also problem solving.
"For Harvest Day, we try really hard to give home gardeners something they can really use in their gardens," explained Judy McClure, Sacramento County's master gardener coordinator. "Instead of some big complex theory, our presentations are very practical. We get questions all the time what do I buy and how do I use it?"
Soil amendments are one of those mysteries. That's what inspired Ingels' talk, titled "What's in the Bag?"
"With the help of master gardeners, we purchased all kinds of soil amendments around town," said Ingels, the extension's horticulture adviser. "I then took samples to a lab to be analyzed."
What the analysis found was a wide variation in products with the same basic name. Depending on compost ingredients, the ratio of carbon to nitrogen could be 10 to 1, 20 to 1 or more.
"If it gets higher than 20 to 1, it can tie up nitrogen," Ingels said. "Plants stop growing. Microbes die off. Eventually, you'll get a release of nitrogen, but it could be several weeks later. It's more common then people think."
Ingels also found that many amendments were 30 percent to 40 percent water.
"Some such as animal-based manure composts can be very high in salts, too," he added. "By adding too much of them, you could be creating saline soil that's toxic to plants."
That's the kind of practical advice gardeners expect at Harvest Day, McClure said.
Other featured speakers include Quentyn Young of Fair Oaks Nursery ("Gotta Have Them: Tools for the Garden"), Rose Loveall of Morningsun Herb Farm ("Tried & True & Heirlooms, Too: Winter Herbs & Vegetables") and Master Gardener Rosella Shapiro ("Small Space & Vertical Gardening").
"Vertical gardening is very popular as more people want to know how they can garden up," McClure said. "Rosella came up with this great way to recycle used electrical conduit. Instead of throwing it into the landfill, you can use it as an attractive way to grow more vegetables."
Making compost particularly vermicomposting with worms also is a popular topic. The master gardeners will demonstrate how along with other techniques. In addition, they'll lead tours through the center's gardens and trial orchard.
"Every disease and insect available right now has visited our orchard," McClure said. "We know how to help you."
Visitors get the opportunity to taste many varieties of fruit, grapes and tomatoes, too.
At the Plant Clinic, master gardeners try to untangle backyard mysteries. Got an unknown weed, volunteer or pest? Bring a sample in a zipped plastic bag for identification.
Harvest Day also marks the annual debut of the popular Sacramento County master gardeners' Gardening Guide and Calendar. The 2013 theme: "Gardening Demystified."
State Fair's bounty
Wandering wondrous rows of corn, jewel-tone egg- plant and perfect peppers, it's easy to be impressed by the bounty of fresh vegetables growing at the California State Fair, which wraps up this weekend.
On 3 1/2 acres next to the livestock pavilions, the State Fair Farm showcases agriculture in a people-friendly way. The farm grows about 80 different crops.
New this year, QR codes posted next to the crops allow visitors to use their smartphones to learn more about what's growing.
Patrons can take some fresh fruit and vegetables home, too. Run by volunteers from Friends of the California State Fair, the Farm's Certified Farmers Market offers a wide range of fresh produce. Proceeds are donated to the Friends' scholarship program.
What about the rest of the harvest? According to Nancy Koch, who oversees the Farm, the produce will be donated to local food banks.
Said Koch, "They've already picked up several large boxes."
When: 8 a.m.-2 p.m. next Saturday
Where: Fair Oaks Horticulture Center, Fair Oaks Park, 11549 Fair Oaks Blvd., Fair Oaks
Details: http://cesacramento.ucdavis.edu/, (916) 875-6913