By T. Eric Nightingale, U.C. Master Gardener of Napa County

Until recently onions were, for me, a smelly vegetable I liked to put on hamburgers. I have recently learned, however, that they have a much more colorful history. Despite their checkered past, many people today credit onions with near-magical abilities.

A little online research will turn up dozens of sites proclaiming the health benefits of onions. Among the purported benefits are lower risk of cancer, heart disease and hypertension; better maintenance of blood sugar; and an enhanced immune system. While these claims have varying degrees of verifiability, one thing is certain: people love onions.

Claims regarding the power of onions are nothing new. Onion cultivation goes way back, about six thousand years or so, and likely began somewhere in Asia or northern Africa. There is evidence of onion obsession in almost every civilization and situation possible.

Onions have been used to treat a variety of medical ailments including indigestion, blisters and even dog bites. They were thought to make warriors stronger and to induce romantic feelings, and they were sometimes used as a currency to pay rent.

Ancient Egyptians held onions in high esteem, believing their concentric rings symbolized eternal life. Artifacts found in tombs appear to be onions fashioned from gold.

On the more practical side, onions were easy to grow, transport and store, making them an ideal food for people in a variety of climates. They quickly spread around the world and became a staple of many cuisines.

Onions are a great source of vitamins C and B, potassium and fiber. Researchers investigating the onion's cancer-fighting abilities have focused on quercetin, a type of antioxidant contained within the onion bulb.

When most people speak of onions, they are usually referring to Allium cepa, the common onion or bulb onion. This species is a large, round bulb that may be white, yellow, purple and red. All species within the genus Allium are often considered onions, taxonomically. Among these are garlic, leeks and chives, as well as a number of ornamental plants. All these plants share similarities in leaf shape, flower appearance and bulb formation. Of course, they also share that particular pungent smell and flavor.

The unique flavor of onions and their kin is due to enzymes in the bulb. An uncut onion bulb emits no smell. But when damaged or cut with a kitchen knife, the plant cells release enzymes that combine to form sulfur compounds, source of the strong, distinctive odor. A separate enzyme produces the acidic fumes that bring tears to the eyes of chefs the world over.

Onions probably evolved to have these intense favors and smells to deter ground-dwelling mammals that would otherwise see the bulbs as a tasty lunch. Humans enjoy the pungency, however. Just look at the booming hot pepper industry.

If your home-grown onions don't have enough of that “oniony” flavor for your liking, your plants may be suffering from a sulfur deficiency. Sulfur is so important to the health of many crops that some call it “the fourth macronutrient” (after nitrogen, phosphorus and potassium).

In Napa Valley, it is unlikely that your soil is deficient in sulfur, but the plants may not be absorbing the nutrient. To be accessible to plants, sulfur must be converted into sulfates through the decomposition of organic matter by soil organisms. You can increase the organic matter in your soil by adding manure, compost or mulch. Growing cover crops and tilling them in when they reach the end of their season is also an option. Of course, it is also possible that the onion variety you purchased was a mild one, so always try a few different types.

While growing onions is not difficult, you should note a few things before beginning. Always read the information on the seed package or set package. Some onions need to be consumed quickly after harvest, while others can be stored through winter.

Another difference is between short-day and long-day onions, referring to the amount of daylight hours the plants will receive. Plant short-day onions in fall for harvest the following spring. Plant long-day onions in early spring and harvest in summer. If you are unable to determine which type you have, look at the recommended climate zones. Short-day onions are suitable for warmer climates such as zone 7 and up.

It is pleasing to know that, when growing onions, we are participating in an activity that humans have engaged in for millennia. These connections remind us of our place in history and our responsibility to the future. That said, onions taste pretty good, too.

Fall Faire: U.C. Master Gardeners of Napa County's second annual Fall Faire will take place on Saturday, October 5, from noon to 4 p.m., at 1710 Soscol Avenue in Napa. Tickets are $5 for adults. Children 15 and under are free with an accompanying adult. Purchase tickets online with a credit card. Cash and check only will be accepted at the door. Find more on the Fall Faire at http://napamg.ucanr.edu/fallfaire/.

Next workshop: U.C. Master Gardeners of Napa County will hold a workshop on “Stinking Roses and Edible Alliums: Grow These Essentials for Your Kitchen” on Saturday, October 12, from 9:30 to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. For more details & online Registration go to http://napamg.ucanr.edu or call 707-253-4221.

The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.

By Iris Craig, U.C. Master Gardeners of Napa County

Gardening can be a positive influence on children, teens and adults. Scientific evidence shows that it can help alleviate stress, instill a feeling of accomplishment, improve respect for nature, even provide a sense of awe and wonder at watching plants grow.

Studies have shown that children of any age may improve motor skills by gardening. They also learn about the life cycle of plants and insects. Many a sunny window in a kindergarten classroom displays fast-germinating radishes, sunflowers and beans in milk cartons.

Do gardening and exposure to green space have a positive effect in the lives of children? As a classroom teacher and parent, I can confidently affirm that they do. One Spanish study found that children exposed to green space at home and at school developed more white brain matter, resulting in better cognitive, physical and mental health, more success in learning as well as a sense of wonder.

Just having plants in the classroom has a positive effect. As a teacher at an inner-city high school, I would bring in a pot of tulips in the spring and place them on my desk, perhaps to brighten my own spirits, but ultimately to spark interest among the students.

One day I noticed a group of ninth-grade boys discussing the changing tulips. As inner-city students, they hadn't seen many flowers near their homes and had no idea that tulips opened flat during the day. Much to my joy, they would “check out the plant” each day and chat about it upon entering the room.

Another study conducted in schools in England, Kenya and India concluded that hands-on garden experience heightened students' sense of responsibility. They improved at teamwork and showed a greater respect for nature and themselves.
School gardens can be incorporated into the science, reading, math and art curriculum. They may improve nutrition, encourage physical activity and boost agricultural and ecological literacy, with resulting improvements in behavior and attitudes.

Spending time outdoors gets children away from technology and television, helps them burn energy and promotes social interaction. When parents of children with attention deficit disorder were asked to describe situations where the symptoms were alleviated, the majority suggested outdoor activities in green settings, including gardening. These activities had a positive impact on behavior, including socializing and impulse control.

But it's not just children and teens that benefit from gardening. A meta-analysis of scientific studies on gardening showed that gardening improves ones mood, and also results in increases in life satisfaction, quality of life, and a greater sense of community. (A meta-analysis is a study looking at the outcomes of many individual studies for overall trends and results.) If you are already a gardener, you know how much better you feel after you spend some time outside in the garden. Evidence of the physical, mental and social benefits of gardening cannot be overstated. Gardening also seems to reduce medical visits and need for medications. Science says you may even lose some weight and increase your bone density if you take up gardening!

If you have been thinking about getting into gardening, want to learn something new or improve your gardening skills, come have fun with us doing the hands-on activities planned for the Napa County Master Gardeners' Fall Faire, where science fair meets carnival.

Some of the Fall Faire's booths with science based fun for adults, children and teens include: Good Bugs versus Bad Bugs; Worm Composting; Carnivorous Plants; Mushroom Madness; Soil: It's Not Dirt; Secret Life of Plants; Pollinator Paradise; Hay/Straw Bale Gardening; Beverages from the Garden; Seeds for Fall Planting; Herb Crafts and Seeds; Planting Succulents; Natural Dyeing; Garlands from Your Garden and Garden Tool Care.

Admire the display of creative scarecrows and vote for your favorite. Stop by the Master Gardener Help Desk to get your gardening questions answered. Want to know which tree to plant? Pick up a copy of the Master Gardener's Trees of Napa Valley (cash or check please). There will be a food truck, a seating area, live music and games for all ages.
Community groups with booths at the fair include 4-H, California Native Plant Society, Natural Resources Conservation District, Napa Compost and Recycling, Connolly Ranch, The School Garden Doctor, Napa Water Conservation District, beekeeper George Altobell and the Bonsai Society.

Napa County Master Gardeners' second annual Fall Faire will take place on Saturday, October 5, from noon to 4 p.m., at 1710 Soscol Avenue in Napa. Tickets are $5 for adults. Children 15 and under are free with an accompanying adult. Purchase tickets online with a credit card. Cash and check only will be accepted at the door. Find more on the Fall Faire at http://napamg.ucanr.edu/fallfaire/.

The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.

Planting Bulbs for Spring Flowers

by Susanne von Rosenberg, UC Master Gardener of Napa County

It's September, and it's obvious that the days are getting shorter and autumn is on the way. One of the most pleasurable activities in a fall garden is planting spring-flowering bulbs. Spring-flowering bulbs add color to a late winter and spring garden, and the right kinds of bulbs will naturalize and reward your efforts for many years.

While we commonly refer to them all as bulbs, these spring-flowering marvels are actually five different types: true bulbs (such as daffodils and tulips), rhizomes (such as bearded iris), corms (freesias and gladiolas are common examples), tubers (cannas and anemones) and tuberous roots (like day lilies and ranunculus).

You see the most common types, including daffodils, tulips, irises, day lilies, calla lilies, dahlias and gladiolas, in many local gardens. Tulips are the most difficult to grow locally because our winters do not provide enough chill, and because gophers adore tulip bulbs. If you want tulips in your landscape, the best approach is to think of them as annuals that you will need to replant every year. Grow them in pots or put them in protective cages if you plant them in the ground. Most other types of bulbs will regrow every year, provided they get the basic care they need.

First, plant them correctly. The best method will depend greatly on the bulb type. True bulbs should be planted at a depth of two to three times their diameter. Bearded iris rhizomes, on the other hand, should be planted with the top of the rhizome at or just below the soil surface.

If you buy bulbs at a nursery, ask the staff about proper care and planting instructions for the types you're buying. If you buy mail order, the delivery should be accompanied by planting instructions.

In our area, bulbs should be planted in October or November, when the soil temperature has dropped below 60°F. All bulbs do best in welldrained soil and should be watered well after planting. If our rainy season starts at the normal time, you won't need to do any additional watering. If rain is delayed or below normal, water the bulbs to give them about the same amount of water and with the same frequency as they would get in a normal year.

Most bulbs need full sun, but some, such as calla lilies, prefer partial shade. You can plant the earlier spring-flowering bulbs under deciduous trees; they will have finished blooming by the time the trees leaf out fully and cast too much shade.

To keep your bulbs performing well year after year, let the foliage die back naturally after bloom. Those produce food that is stored in the bulb to nourish next year's flowers. Also give them a light application of phosphate-heavy fertilizer (such as bone meal) every year. After three or four years, many types of bulbs become crowded and need to be divided. You can tell that it's time to divide them when you see a lot of leaves growing in a crowded area, but you get fewer flowers than in previous years.

Many bulbs native to the Cape Province of South Africa, which also has a Mediterranean climate, will do well here and naturalize easily. Try spraxia (also known as wand flower or harlequin flower), ixia or babiana. Another interesting variety to consider is rain lily, a Mexican native (Zephyranthes) that looks a bit like a crocus and comes in many colors.

You can also plant native bulbs this fall. One advantage of natives is that they bloom when native insects need them. They are also adapted to our climate and do not require any special soil preparation.

There are more than 200 species of native California bulbs, corms and rhizomes. Some examples include Coast iris, blue-eyed grass (a very small native iris), snake lily, camas bulbs and fritillaria. The Calflora website (www.calflora.org) lists 23 native species.

If you buy native bulbs, make sure they are ethically sourced, not collected from the wild but propagated by the nursery that sells them. Because native bulbs are likely to be more expensive, it's particularly important to be well-informed about the growing conditions they require.

For example, camas bulbs prefer soil that is very moist in the spring and then dries out, conditions typical of seasonal wetlands and the edges of creeks. Give them a home in an area of your garden that is soggy during the wet season, but then dries out. They have a long flowering period (typically April through June).

Camas bulbs were used as a food source by native American tribes and are very appealing to gophers. They are one of the few native bulbs that need gopher protection. California native bulbs are a worthy addition to a native garden and also make great potted plants.

Next workshop: “Stinking Roses and Edible Alliums: Grow These Essentials for Your Kitchen” on Saturday, October 12, from 9:30 to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. For more details and online registration go to http://napamg.ucanr.edu or call 707-253-4221.

The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.

Planning a drought-tolerant garden can be a challenging endeavor. Knowing which plants to use and where to plant them is difficult as information and advice can vary significantly. However, there are a few simple things you can do to make the process easier.

The first task is to become intimately acquainted with your garden. Watch the way the sun moves and where the shade falls throughout the day. It may seem obvious that how much sun a plant receives will affect how much water it uses, but not all plants labeled for low water use will thrive in full sun.

Knowing the locations in your garden that receive shade from summer heat can greatly affect the health of your plants and the maintenance required to keep them looking attractive.

Note how wind moves through your garden. Evapotranspiration, the loss of water through plant leaves, increases significantly with high, hot or dry winds. On a cloudy yet windy day the plants in your garden could dehydrate more than you expect.

Finally, get up close and personal with your soil. Check its water retention by digging a hole about a foot deep and wide and filling it with water. Hope for the water to percolate through in about an hour, signifying good drainage.

Many drought-tolerant plants, especially succulents and cacti, will rot if soil drains too slowly. Conversely, if the soil drains too readily, it can be difficult to keep even low-water plants adequately hydrated.

All of these factors will help you form a picture of how water will be utilized in, and move through, your garden. This knowledge is a useful tool when choosing new plants.

When working on creating a drought-tolerant garden there are some preconceptions it is best to discard. When many people think of a garden, the image that comes to mind is of a classic English garden. This is understandable as modern home gardening and many of its traditions originated in Europe.

But England has a different climate than Napa, and it is not realistic to expect our gardens to look like English landscapes.The plants found in English gardens are often not good candidates for a Napa Valley garden, least of all a drought-tolerant one.

Many of the best-known annual plants are thirsty in our climate, as are many popular perennials such as hydrangeas, camellias and gardenias. Tropical plants, while visually stunning, are often troublesome as well. Even if they are not labeled as requiring a lot of water, the relatively low humidity in Napa Valley can make it difficult to keep them healthy.

Changing our expectations for our gardens does not mean lowering them. A garden can use less water and remain visually pleasing, lush and colorful. In a sunny location, shrubs such as salvia and lavender can be placed among large succulents such as aloe and agave. The contrast of soft and sharp textures is pleasing to the eye. The salvia will bloom most of the summer, while many aloe, such as Aloe capitate, bloom in the winter.

Many popular groundcover-type plants have shallow roots and need frequent watering. These can be easily replaced by a clumping or vining succulent. A favorite of mine is ice plant, Delosperma cooperi, which produces a carpet of purple-pink blooms from spring through summer.

Identifying plants that work in a drought-tolerant garden is easy after some practice. Generally speaking, plants with large, glossy leaves are a poor choice. These plants will lose a lot of water to evapotranspiration and are prone to sunburn. Plants with dusty or fuzzy-looking leaves are much more adapted to hot, dry conditions.

The roots of a plant can also tell you something about its water needs. Small, shallow roots will need more frequent watering than large, deep-burrowing ones. Never hesitate to gently remove a nursery plant from its pot and inspect the roots. They are a key indicator of plant health.

An important bit of information often missing on plant labels is the term “once established in the ground.” Succulents excepted, a potted plant will usually need more water and fertilizer than the same plant in the ground. Many drought-tolerant shrubs survive by growing broad or deep root systems. It takes at least a year for new plants to develop a useful root system, during which time they will need additional water.

Knowing these facts about your garden and the plants in them, as well as altering your perception of how a garden should look, can make an enormous difference in your relationship with it. You can minimize required maintenance and reduce your stress, leaving only the pleasure of enjoying the beautiful space you have created.

Next workshop: “Home Vineyard: Part 2” on Saturday, September 14, from 9:30 to 2:00 p.m., in Calistoga. Learn techniques to maintain your new or existing home vineyard. Workshop location will be provided after registration. For more details & online Registration go to http://napamg.ucanr.edu or call 707-253-4221.

The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.