By Susanne von Rosenberg, U.C. Master Gardener of Napa County

After you have been gardening a while, you may want to branch out and try growing more unusual plants. Being successful with less common plants requires more knowledge and research. Experience helps, too.

Uncommon plants fall into three categories. Some are simply unfamiliar but not difficult to grow, such as watermelons that don't have red flesh. (I like ‘Cream of Saskatchewan,' which has a creamy white interior.) We're all familiar with pluots (a 75 percent plum-25 percent apricot cross), but there are also plumcots (equal parts plum and apricot) and apriums (25 percent plum-75 percent apricot), as well as a cherry-plum cross. All of these crosses can thrive in Napa Valley, but be sure to check the basics before planting them. Does your microclimate provide enough hot days to ripen that watermelon, or enough chill hours for the aprium?

Other uncommon plants may be more challenging because you don't know anyone who has grown them. The jujube (also known as Chinese date or red date) is a fruit tree that at least one Napa County nursery offers in bare-root form. But do you know anyone who has grown one?

For such plants, you need to research the pros and cons yourself. Jujubes have spines on young wood, require unusual pruning techniques and tend to sucker. On the positive side, they thrive in almost any soil, are drought-resistant, have a long productive life (more than 50 years), often fruit within two years of planting and produce nutritious fruit.

Other plants may be rare in Napa County because they are difficult to grow here. They may not like our climate or need more day length than we have. While you can modify climate somewhat (depending on how much time and money you want to invest), there is little you can do about day length.

Plants from equatorial areas are used to a consistent 12 hours per day of sunlight and may not flower or fruit if the daylight period is longer or shorter. Chayote squash tends not to set fruit in Napa Valley until late August or early September, when the days are shorter, and then our growing season is cut short by frost before the squash have time to mature.

Before planting any uncommon plant, find out whether it is invasive in California. A few years ago, I became enthralled with a plant called autumn olive, also known as silver berry. Then I learned that it is considered invasive everywhere it is found. Even so, you can still buy it in nurseries, including on-line nurseries.

Next, think carefully about your microclimate. Consider how much sun or shade the plant requires, how much heat it needs or can tolerate and whether it requires some winter chill. Is the plant frost- or wind-sensitive? What are its needs with regard to humidity? What is its typical growing season, and is our growing season long enough for it to mature fruit?

What kinds of pests and diseases does this plant suffer from in its native habitat, and do we have any of these pests and diseases in Napa Valley? Make sure the plant can thrive in your type of soil and that, when full grown, it will fit in your garden. I was thinking about planting pecan trees until I learned that they typically grow 65 to 130 feet tall.

Finally, think carefully about how much time and money you want to invest. You could grow bananas in a heated greenhouse in our climate. Do you want to spend the money to install and heat a greenhouse?

Do your research using reliable sources such as the University of California Cooperative Extension, other university websites, information from U. C. Master Gardeners, reputable nurseries and other recognized authorities such as the California Rare Fruit Growers or California Native Plant Society. When considering information from other universities, be aware that their recommendations are based on the climate in that region.

Enjoy your explorations and let U. C. Master Gardeners of Napa County know what types of unusual plants you have growing in your yard.

The UC Master Gardeners of Napa County 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.

Few other vegetables are more representative of fall than pumpkins. Come October, mounds of pumpkins of various shapes and sizes are a common sight in Napa Valley. While they may seem to suddenly appear, pumpkins have a fairly long growing season. If you are considering growing pumpkins in your garden for a fall harvest, it's time to plant.

Pumpkins belong to a large botanical family that includes melons, cucumbers and other squash. Some tiny pumpkin varieties can fit in the palm of your hand. The record-setting types weigh in at over a ton. Pumpkins also come in shades beyond jack-o-lantern orange. For an unusual addition to your garden, seek out white, red or blue-skinned varieties.

One bonus of planting pumpkins is that they attract bees. Honeybees will happily do the work of pollination, but a garden with a range of plants will lure and nurture other bee species. Squash bees tend to fly early in the morning, before honeybees get going. You may never even know that they have visited your garden. To encourage squash bees, consider adopting a no-till regimen. Squash bees nest several inches below the soil, and frequent tilling can destroy their habitat and nesting populations.

It is a joy to watch pumpkins grow, but they do need space. If your garden has ample room, allowing the plants to ramble can help shade and cool the surrounding soil and prevent weeds from growing. Before planting, amend the soil with compost to get plants off to a healthy start. Plants can be started in small pots or direct-seeded. If you are aiming for maximum size, feed with a high-nitrogen fertilizer to stimulate leaf growth. When blooms appear and fruit set occurs, phosphorus and potassium become more important.

Once established, pumpkins grow fast. To promote larger pumpkins, select one or two good specimens and remove all others on the vine. This pruning will help the plant transfer nutrients to the remaining units.

Squash leaves can be susceptible to mildew. Irrigating with drip or soaker hose is preferable to overhead watering. Remove diseased leaves as soon as possible and do not overwater. Leaves may wilt on hot days but typically recover as the weather cools. If wilting persists, check to make sure plants have adequate water

Common pumpkin pests include cucumber beetles and vine borers. A home gardener can tolerate some damage rather than resorting to chemical sprays. Remember that pollinators and other beneficial insects might be frequenting the plant, too. Use light-permeable row covers to protect plants if an infestation is particularly heavy.

Trap crops can also help reduce insect damage by providing an alternative food source. Crop rotation can help by eliminating available food sources for future generations of pests. The University of California's Integrated Pest Management database is an excellent resource for pest- and disease-control advice.

Besides being delicious, pumpkins have other advantages for the home gardener. They can help minimize weed growth around taller plants such as sunflowers. Native Americans understood the wisdom of planting pumpkins with beans; the beans add nitrogen to the soil and pumpkins are heavy feeders. Many pumpkins store well and can provide tasty meals in winter when many vegetables are out of season.

You don't have to wait for the pumpkin to mature before enjoying the plant. The leaves are edible and can be cooked like spinach. Choose young, tender leaves for that purpose. Of course, the seeds are edible, too. Enjoy them roasted and salted to increase the food value of your crop, particularly if you have limited space. Saving seeds and swapping with friends can increase your garden's diversity with no extra expense.

Pumpkins grow well in Napa Valley. Consider planting a beautiful heirloom cultivar to enjoy as a table centerpiece in winter. Between the pumpkin's tasty flesh, its seeds and its nutritious leaves, this plant hits a triple.

Workshop: U.C. Master Gardeners of Napa County will hold a workshop on “Succulent Plant Success” on Saturday, July 7, from 9:30 a.m. to 11:30 a.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Bring your love of succulents to this workshop dedicated to helping succulent gardeners grow the show-stopping plants we all hope for. Master Gardeners will show you the right kind of soil and containers and how to care for your succulents. They will also discuss myriad succulent types to help you make a succulent garden for yourself or to give as a gift. Please bring succulent cuttings you would like to share.Online registration (credit card only); Mail-in/Walk-in registration (check only or drop off cash payment).

Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.

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

There is nothing quite like walking through, or relaxing near, one's own garden. Gazing upon the plants that have thrived and bloomed, the result of hard work and tender care, is a singular experience. Only a gardener can truly know the special joy that it brings.

There is another experience unique to gardeners. It is when, as they let their eyes wander over the delicate curves and rich colors of a plant, something catches their eye. It may be a strange color or an odd pattern. Perhaps a flicker of movement in the corner of their eye.

This is the time when the gardener's lip curls slightly into a sneer and they bend down, squinting into the foliage. Then they see it, something that shouldn't be. Something uninvited. Then, an eyebrow raised, they wonder “what exactly, is that?”

Pest intrusion is an undesired, yet unavoidable, part of having a garden. Some plants are more susceptible than others (pests usually want to eat the same things we do), but there is no guaranteed way to prevent contamination. Even the most dutiful gardeners will find themselves facing the task of extermination. First, though, comes the challenge of identification.

Correctly identifying a garden pest is an important part of Integrated Pest Management. Yes, a liberal spray of general insecticide would solve the immediate problem. This action, though, would only open the door for many other, perhaps even more serious, threats.

The best approach is to identify the intruder and approach it with a personalized attack. Looking down upon some anonymous, multi-legged critter, you may find it difficult to know where to begin. I always begin my reminding myself that, while creepy, crawly, and generally unattractive, the creature may not be a threat.

Many of the bugs in our gardens are neutral, and some are even beneficial. I assume them “innocent until proven guilty.” With this in mind, I begin my investigation.

What type of plant are they on? While some pests attack a range of plants, some only target specific ones. Often the answer to this question will narrow the range of possibilities considerably.

Many books and websites detail common garden pests, but my first stop is always the University of California Integrated Pest Management website (www.ipm.ucanr.edu). I find the type of plant I am working to save and am presented with a list, complete with pictures, of the organisms that attack it. Those who are patient, or generally curious, can read through the various entries until one seems to match the invader. To make the process quicker, I recommend noting a few key attributes of the pest in question.

The first thing I always look for is plant damage. Is the pest chewing on the leaves, sucking out its juices, or boring into it? Sometimes the damage is the only clue I have to work with, as in the case of nocturnal pests such as snails and slugs.

Sometimes it can be difficult to tell pest damage from disease damage, so keep an open mind if no pests are present. The type of damage indicates how the pest feeds, a useful clue to identification.

When inspecting the pest itself, I start with the basics. Sometimes different bugs have similar coloring or markings, making it difficult to tell them apart from memory, when away from the garden. Next, I note the number of legs. A handheld magnifying lens makes this easier and is arguably the most useful tool a gardener can own.

If the bug has eight legs, it is an arachnid. Six legs, it's an insect. If I have an arachnid on my hands, I make very sure it is a pest and not a spider. Spiders are one of the most beneficial creatures in our gardens, consuming enormous amounts of bugs each year. As much as possible, I leave them to their work.

If it is not a spider, chances are it is a mite and will require appropriate treatment. A six-legged invader requires further investigation as the options are more numerous.

At this point, it helps to note other parts of the pest. Does it have wings? Does it have large jaws, pinchers or antennae? Is it creating or secreting any substances? I have occasionally overlooked these telltale characteristics, figuring that a creepy bug would, of course, have some weird features.

Armed with facts from my detailed investigation, I often find my research goes quickly and smoothly. Once the pest is identified, treatment becomes obvious and, in some cases, not even necessary. A few pests cause minimal damage in small numbers and depart the garden on their own. In these situations, it would be a waste of time and money to apply an insecticide.

Other times all that is required is some easy cleaning or pruning. If I need to take more drastic action, at least I know my enemy.

When I struggle to address my garden problems on my own., I turn to the U.C. Master Gardeners of Napa County help desk (hours below). The friendly and knowledgeable people there are always excited to help solve a bug mystery.

Workshop: U. C. Master Gardeners of Napa County will conduct a workshop on “Make Room for Salvias” on Saturday, April 21, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. Every gardener should be able to find a salvia just right for that little (or big) space.  Salvias are long-lasting, attract butterflies and pollinators and have attractive foliage. Learn how to select and care for these versatile plants.Online registration (credit card only);Mail-in/Walk-in registration (cash or check only)

Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.

Peter Jacobsen's renowned Yountville orchard had humble beginnings. “We had no qualifications except that we had no fear of dirt,” says Jacobsen, a dentist with a San Francisco practice.

I find his simple statement both comical and inspiring. When Peter and his wife, Gwenny, bought their Yountville home, they had no plans to grow food. But the home came with land that had already been partially prepared and gardened. One thing led to another, and today the fruits and vegetables they grow are prized by many of the valley's premier chefs.

Not only does Peter have a mouth-watering vegetable garden, but he also tends an impressive collection of fruit trees. I was fortunate enough to visit and was fascinated by his mulberry trees.

We don't see many mulberry trees in Napa Valley, yet they thrive in our climate and are fairly drought tolerant. The fruit looks something like an elongated blackberry. The tree itself has attractive, hanging branches that make it a handsome addition to a garden.

Mulberries are easy to harvest and delicious. As I learned from Peter, the trees produce fruit only on new growth. As a result, you can achieve higher yields by pruning after harvest and pruning to maximize branching.

As we walked through his orchard, Peter picked several stone fruits that I had never tasted. My two favorites were the Damson and Mirabelle plums.

The Damson plum is the most beautiful plum I have ever encountered. It looks something like a giant blueberry. The flavor is slightly astringent, but it is a great plum for cooking.

Grown throughout western Europe, the Mirabelle plum is red or yellow and contains white flesh. It is tasty when fresh but is most often made into wine or jam. Both the Damson and Mirabelle plum trees are also often used in Europe as hedges or windbreaks. They are sturdy trees and can protect their weaker neighbors.

Interestingly, Peter advises against attempting to grow cherries, apricots or avocados in the Napa Valley. In his opinion, these trees are incompatible with the local climate. This was a relief to me, as it assuaged my guilt over the death of my avocado tree last year.

The Jacobsen orchard experiences the same challenges as the rest of us; it is not immune to pests and diseases. The Jacobsens practice Integrated Pest Management, and the results are apparent.

While both fire blight and peach-leaf curl have hit some of his trees, Peter responds with prudence. I asked if he recommends copper fungicide for treating the leaf curl, and he said he uses it sparingly, worried about copper buildup in the soil. He is willing to tolerate some peach-leaf curl as it does not impede fruit production.

On the other hand, Peter does have a reason to battle peach-leaf curl. During my visit, he plucked peach leaf and crumpled it in his hand. What a surprise to have the strong smell of almonds fill my nose. Peter's chef-customers are currently using peach leaves to infuse dishes with this aroma.

The Jacobsens use no chemical fertilizer in their orchard but instead plant cover crops around the trees. Planting peas, mustard and clover helps to return nitrogen and other nutrients to the soil. The thick coverage also leaves little room for weeds.

As I learned from Peter, all we need to grow a garden is a little knowledge and a lot of motivation. As humans, we live in a structured environment, filled with things that we have designed and built. I think it's important to remember that plants want to grow, that they need us much less than we need them.

This realization can take some of the stress and doubt out of gardening. If you know your land, what grows well there and what makes it thrive, you are halfway to your goal. The only other thing you need is a willingness to get a little dirty.

Workshop: The UC Master Gardeners of Napa County will hold a workshop on “Toxic and Carnivorous Plants and Mushroom Kits” on Saturday, October 28, from 9:30 a.m. to 11:30 a.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Foxglove. Lily-of-the-valley. Wisteria. These common plants and others are toxic. Who knew? Sundew. Venus flytrap. Pitcher plant. They're carnivorous. While we would not touch a mushroom in the garden, growing edible fungi from kits is easy and neither toxic nor carnivorous. Explore the fascinating properties that plants have to protect them. Online registration (credit card only);
Mail-in registration (check only or drop off cash payment)

Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.