By Susanne von Rosenberg, UC Master Gardener of Napa County
Growing some of your own vegetables is one way to contribute to a more sustainable world. Locally grown food, if grown correctly, has a much smaller environmental footprint than food imported from elsewhere. The good news is that you can make your vegetable garden even more sustainable by a few simple practices: reducing the inputs, minimizing waste and building your soil.
Building your soil is the best thing you can do for healthy plants. It helps sequester (store) carbon, and it provides an opportunity to reuse garden waste on your property. I hope you compost your fruit and vegetable scraps (nothing diseased, though) and other garden waste.
Compost is a wonderful soil amendment and mulch. Natural biological processes will help break down those materials that need to break down, and earthworms and other soil critters will mix the amendments into the soil without you having to lift a finger.
Other things you can add to the soil include shredded newspaper (if your newspaper uses soy-based inks) and cardboard. You can use overlapping layers of cardboard covered with a layer of mulch to help control weeds. In those parts of your garden that stay moist, the cardboard will break down completely in three to four months.
It's also a good idea to avoid tilling or turning your soil. Tilling or turning your soil reduces the organic matter in your soil. Most plants, once you're done harvesting, can simply be cut down. Leave the root mass in the soil to add organic matter.
You can further improve your soil and sequester more carbon by growing cover crops. Don't turn the cover crops into the soil; just cut them down, chop them up and leave them in place as mulch.
Reducing inputs simply means buying less stuff to support your garden and using less water. By now, we all know how to reduce our water use: use drip irrigation, mulch and monitor your plants to make sure that you don't over- or under-water them.
So how can you buy less “stuff” such as plants and seeds, fertilizer and weed- or pest-control products? To reduce your need for fertilizers, you can plant cover crops in the winter, especially legumes such as fava beans to fix nitrogen in the soil. In healthy soil, nutrients already in the soil are more available to your plants.
If your soil does need more nutrients, try to find local sources of manure. (Manure should be composted before it is applied to your garden.) If you buy fertilizer, apply the same principles that you do for your other purchases: figure out where the ingredients come from, and buy as local and sustainable as possible.
To reduce your purchases of plants and seeds, grown your own plants from seed, share your seeds with other gardeners, and save seeds from open-pollinated varieties. It makes sense to share your seeds because fresh seeds (no more than two years old) produce the best plants.
Growing your own plants from seeds is fun. It allows you to grow more varieties than you can purchase and to have plants when the nurseries may not carry them. For example, the ideal time to set out broccoli and cauliflower seedlings for fall harvest is in mid-August, but just try finding seedlings for these crops in nurseries in August.
Some of the best ways to control weeds are to control where you water using drip irrigation. Mulching also helps minimize weed germination, or you can hand-pull or hoe weeds, of course. As long as a weed has not set seed, add it to your compost. It's just more organic matter. Bindweed (field morning glory), blackberries and Bermuda grass can sprout from bits of stems and roots, so allow them to dry out completely before adding them to compost or using as mulch.
Healthy plants, properly tended, will be most resistant to pests and diseases. For insect pests, you can hand-pick the critters. (I sometimes shake plants over a bowl if a plant has been invaded.) Or you can wait for natural predators to arrive and take care of them for you. Look first to non-toxic methods, such as spraying aphids off with a garden hose
If you hand-pick critters, cool mornings or evenings are best because insects will be much slower when it's cold. Plants also have their own forms of defense. They produce compounds in their tissues to help deter predators. Consider ignoring some damage. Plants communicate with each other through hormonal signals from their roots, and the plants near the one that is being attacked will also produce defensive compounds.
There are many ways to make your vegetable gardening more sustainable. The important thing is to keep improving.
For more about caring for the soil:
Healthy soils for a healthy California. Check out the Home and Garden section.
https://ucanr.edu/sites/soils/
Building soil health:
https://ucanr.edu/sites/Nutrient_Management_Solutions/Management_Goals/Build_Soil_Health/
Tips to improve home garden soil:
https://ucanr.edu/sites/soils/Soils_for_Homes_-_Gardens/
Master Gardener Workshop: “Growing Tomatoes in the Home Garden” on Saturday, April 4, from 9:30 a.m. to 11:30 a.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Learn tips and tricks for cultivating great tomatoes including the latest research on care. On-line registration (credit card only) or Mail-in/Walk-in registration (cash or check only) or call 707-253-4221.
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.
By Donna Woodward, U. C. Master Gardener of Napa County
Twice a year, Napa County Master Gardeners conduct vegetable field trials. Members of the field-trial committee plant three different varieties of the same vegetable and monitor the results so we can share what we have learned with the public.
In the spring of 2018, we chose sweet peppers for our trials. The three varieties chosen were Gypsy (a hybrid), Golden Giant (a hybrid) and Jimmy Nardello (open-pollinated).Seeds for both hybrid varieties were purchased from Burpee; the Jimmy Nardello seeds came from Baker Creek.
We started the seeds in 4-inch pots in a greenhouse and planted the seedlings in our gardens between April 25 and May 5. Drip irrigation was recommended. Since peppers like rich soil, we were advised to amend the soil with compost and add a balanced fertilizer, such as 5-5-5. We planted the peppers 18 to 24 inches apart and were cautioned to keep them well-watered in hot and dry weather but to avoid getting water on the fruit.
All three varieties produced plenty of tasty sweet peppers. Jimmy Nardello was a pretty, bright red pepper with a sweet, slightly spicy flavor. Gypsy was a yellow-green pepper which also had a piquant flavor. Golden Giant, true to its name, produced very large, rounded fruit with thick flesh. The others were elongated, tapering from broad shoulders to a pointed tip.
Our committee generally reported good results for all three varieties. All benefited from some support, but it was especially important for the Golden Giant. Small tomato cages worked well. The peppers did not suffer much insect damage, the only report being in mid-September. All three varieties were somewhat vulnerable to sunburn and blossom-end rot.
Participants completed a survey rating the three varieties, on a scale of 1 to 5, for flavor and productivity. The scores were all high, ranging from 4.3 to 4.6, with Gypsy taking the honors.
However, in accumulating the participants' comments, a more complicated picture emerged. Individual experiences were often contradictory. The only variety that got predominantly positive reviews was the Jimmy Nardello. It received the most praise for flavor and was also the most prolific. It was the earliest to mature, about a month earlier than the other two, and continued to produce long into the season.
Reactions to the other two peppers varied widely. Comments regarding Golden Giant's flavor included “bland,” “delicious,” “good but not outstanding” and “bitter.” Comments on Gypsy were also at odds: “prolific and tasty;” “not prolific enough and not tasty or sweet;” and “best taste; pretty colors.”
How do we explain the difference between the numerical scores and the comments? Apparently rating by numbers doesn't tell the story. The comments bring out some of the variables that can influence outcomes in such trials.
Growing conditions can vary widely within Napa Valley. Soils, sun exposure and elevation can differ even within a small area. The pepper variety that performs best for you may well depend on the conditions in your garden. There was also some variability in how participants followed recommended cultivation guidelines. A few tweaks in growing practices might yield different results. We gardeners all know that trial and error is a great teacher.
Perhaps naming a winner isn't the most important outcome of this trial. All three of these pepper varieties can produce excellent fruit, as can many other sweet pepper varieties. The most valuable lessons relate to growing peppers in general:
Peppers are susceptible to sunburn. Planting them close enough for the leaves of plants to just touch will help protect them from sunburn.
Leaf puckering is a symptom of phosphorus deficiency. Phosphorus affects the health and growth of the plant and helps the fruit to set and develop. Dig some into the planting hole when transplanting. Most pepper plants appreciate a few tablespoons worked and watered into the soil every couple of weeks during the growing season. If leaf puckering occurs, use more.
Garden-grown sweet peppers are delicious. They are a wonderful addition to green salads, stir fries and other dishes, adding color, flavor and nutrition. If possible, make room for sweet peppers in your vegetable garden this spring.
Workshop: “Sustainable Vegetable Growing” (Four-Part Series) on Sundays February 23, March 1, March 8 and March 15, from 2 p.m. to 4 p.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. For more details & online registration go to Online registration (credit card only) or call 707-253-4221.
Workshop: “Spring and Summer Vegetables” on Sunday, March 8, from 1 p.m. to 3 p.m., at the Yountville Community Center, 6516 Washington Street, Yountville. Do you want nutritious, easy-to-grow and utterly fresh food from your garden this spring and summer? To register, call the Parks & Recreation Department at 707-944-8712 or visit the department's web site.
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.
While skimming a magazine from England called Permaculture, I found an article about mounding. The article described how to build mounds in your garden and what materials to use. Over time, the soil becomes richer from the decaying materials. Also, the sides of the mounds provide more space to plant. I realized that I have already done this in my own garden.
When I removed my back lawn many years ago and replaced it with mounds, i used the dried turf from the lawn. I turned the sod upside down for the base of each bed, then proceeded to build the beds up with mulch from my own yard; branches, bark and trimmings. On top of the whole thing I added compost and some garden soil.
These beds were created 20 years ago and are still looking good. I have some major plantings on them, such as small maple trees and lily of the Nile (Agapanthus). Annually, I add compost and dried leaves to enrich the soil.
I also created a mound when I gave up on my huge walnut tree. The squirrels were stripping it and dropping unripe walnuts everywhere, including into my fish pond. After much consideration i had the tree removed.
After the stump was out I started to fill the depression with organic materials from my yard. The first layer was sticks and stumps from small prunings around the yard. Then I added leaves and other garden waste and piled soil on top of the whole thing. Since I planted figs on this area, I call it Fig Hill. It also gets annual composting and other soil added to keep the height.
The sticks and other organic materials that I put in these mounds act like a sponge, absorbing water and holding it for the plants. If you have soil that does not drain well or is hard to work, mounds will help with both of these problems.
With both of these experiences, the results repaid the work. Now is a good time to start such a project in your own yard as you prune and clean up in your garden.
As I learned from the magazine article, one approach is to dig long trenches and then fill them with logs, branches, leaves, grass clippings, straw, cardboard, black and white newspaper, cured manure, compost or other available materials. Then you top it all with good soil. Water well and let the soil and materials start to decompose and settle. Then you are ready to plant vegetables or flowers in your mounds.
The organic content of the mounds gives off heat as it decays and keeps the soil warmer. And the decomposing wood gives off nutrients for years. Hard woods will take longer to decay than soft woods.
An added benefit of the mound method is that it doesn't require tilling. No-till gardens are better for the creatures that live in the soil, like earthworms, so, ultimately, they are better for soil health.
Mound gardens also mean less bending for the gardener.
The article recommended constructing steep beds to avoid compaction from foot traffic. Steep beds create more surface area in your garden for plants, and the height makes easy harvesting. The greater the mass, the greater the water retention.
Some of the beds shown in the article had straw on the top and sides to hold the materials in place. Others had wire sides with plants inserted between the wires. One gardener used shipping pallets to hold everything in place with plants planted between the slats.
Next workshop: “Sustainable Vegetable Growing” (Four-Part Series) on Sundays February 23, March 1, March 8 and March 15, from 2 p.m. to 4 p.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. For more details & online registration go to Online registration (credit card only) or call 707-253-4221.
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.
By Heather Dooley and Pat Hitchcock, UC Master Gardeners of Napa County
The recent rain and cool weather have given us plenty of time to pore over all those seed catalogs looking for a new vegetable variety to try or reordering seeds for our favorites. It's time to start planning your summer vegetable garden (although it's not planting time yet).
Fortunately, we live in an area with a Mediterranean climate, characterized by long, dry summers and mild, rainy winters. As a result, we have two cool seasons annually for gardening, one in late summer and early fall and the other in early spring. Our warm season typically starts in late April when the soil is warm enough to plant tomatoes. Now is the time to start planning for that warm season.
You can start your own warm-season vegetables now in pots. Tomatoes, peppers and eggplants are easily started from seed indoors. These vegetables require warmth to germinate so it's a good practice to put seed-starting trays on a heat mat.
All seeds need the correct temperature and moisture to germinate. But after they sprout, light becomes all important. Put baby seedlings in a sunny spot by a window or, if using a grow light, keep the light about 1 inch above the leaves to prevent spindly, weak plants.
If your seedlings do get leggy or aren't dark green, they need more light. Keep soil moist but not soggy and use a half-strength liquid fertilizer once a week. In about six weeks they will be ready to plant outside.
Be sure the area where you intend to plant your seedlings gets enough sun. Six to eight hours is the minimum for most vegetables.
Do you have a plan for irrigation? And have you examined your soil? Is it nice and crumbly, like a piece of chocolate cake? Or is it waterlogged clay? Clay soil holds micronutrients but typically needs to be amended with compost to lighten it, so it has air pockets for the nutrients to cycle.
Have you been adding organic matter to feed the soil microbes? Soil is alive. It has both macroscopic organisms (the ones we can see), such as earthworms, aerating the soil and decomposing organic matter and also microscopic organisms such as bacteria and fungi.
Mycorrhizae are fungi that live in association with the roots of plants. These fungi collect nutrients for the plants in exchange for carbohydrates. It's a wonderful example of life forms helping each other. There's a whole conversation going on underground in healthy soil.
Don't neglect weeds. Most soils have a large amount of weed seed just waiting for the right conditions. Weeds compete with your vegetables for water and nutrients. Controlling them is a constant part of gardening but can be managed by depriving the weeds of water and light. Mulch your beds to exclude light, water only where necessary for your vegetables and disturb the soil as little as possible to avoid bringing up a new crop.
Plant healthy transplants at the right time to encourage growth and to out-compete weeds. Chemical weed controls are not recommended in a vegetable garden and not needed in most situations.
Now that you have a sunny spot with great soil, access to water and no weeds, what do you want to grow? Ask yourself why you are gardening. Is it for flavor, to save money, to harvest organic produce or to have access to unusual produce varieties?
It's tempting to want to grow everything, but properly spaced plants will be healthier and more productive than plants spaced too closely. Make a planting plan on paper. Think about the size of the vegetable when full-grown and how long it will be in the ground. An indeterminate tomato plant will eventually need almost nine square feet of growing ground and will need to be supported with a strong five-foot-tall cage. Can you stagger plantings for a longer harvest season?
It is better to grow fewer plants well than to have a large vegetable garden that you can't take care of. Gardening is work and therapy, and you get tomatoes, too.
See complete list of upcoming events on our website calendar http://napamg.ucanr.edu
Free Talk, 1 hour: “Growing Summer Vegetables” at the Napa Public Library on Thursday, March 7, from 7 p.m. to 8 p.m. Learn what you can grow in the summer, what to plant and when, and how to have a harvest all summer long. No registration required.
Workshop, 2 hours: “Growing Spring and Summer Vegetables” on Saturday, March 9, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Do you want nutritious, easy-to grow and utterly fresh food from your garden this spring and summer? Learn what the garden needs to successfully produce spring and summer vegetables from seeds and plant starts. In addition to growing basics and hands-on activities, this program includes watering, fertilizing and harvesting tips, with a dash of Integrated Pest Management for pest and disease control. The delight of growing your own groceries is matched only by savoring them at harvest. Online registration (credit card only); Mail-in/Walk-in registration (check only or drop off cash payment).
Workshop, 2 hours: “Summer Vegetables” on Sunday, March 10, from 1 p.m. to 3 p.m., at Yountville Community Center, 6516 Washington Street, Yountville. Get tips for growing your own summer vegetables. Learn some basics, get keys to success, and do hands-on activities to learn about new varieties and review old favorites. Enjoy healthy vegetables taken straight from your garden to your table. The delight of growing your own vegetables is matched by savoring them at harvest. Online registration or telephone the Parks & Recreation Department at 707-944-8712.
Demonstration garden update: UC Master Gardeners of Napa County have begun the process of re-establishing a demonstration garden in Napa Valley. For further developments, please visit the Demonstration Garden link on our website ( http://napamg.ucanr.edu/).
Master Gardeners are volunteers who help the University of California reach the home gardening public with research based gardening information. U. C. Master Gardeners of Napa County (http:/napamg.ucanr.edu) 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 Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
/span>By David Layland, U. C. Master Gardener of Napa County
It's that time of year: time to start thinking about planting this year's vegetable garden. It's still too early to actually plant seeds or starts but it's not too early to do a little planning.
By now the remnants of last year's garden should be decaying in your compost pile. If not, removing any plant debris from last year should be your starting point. You want a clean slate in case any of last year's plants were diseased.
Once you have cleaned up your garden beds, it's time to add compost. Ideally, you did so last fall, but if you're like me, it didn't happen. Add a good three to four inches of compost so that plants have an ample supply of organic matter to feast on all season. Such a healthy addition of compost will reduce or even eliminate the need for fertilizer.
The time-honored method is to dig in the compost, but many people are now advocating a no-till approach. Digging breaks and disrupts the long, delicate filaments of mycorrhizal fungi that live on plant roots. If undisturbed, these fungi grow downward, branching out like a second set of roots and giving plants access to nutrients deep in the earth.
If the soil is tilled, this network of fungi will need to re-establish itself. When seeds or starts are planted without tilling, they can often hook up with last year's mycorrhizae almost immediately, which gives them an early advantage.
However, soils with poor structure do need to have organic matter thoroughly incorporated into them. If your soil has too much sand or clay, if it is compacted, or if it lacks organic matter, then by all means dig.
Before deciding what to plant and where, take a trip back in time. If you are like me, you have maintained a garden journal to record what you grew in your vegetable garden each year. This information is critical as you don't want to plant vegetables in the same family in the same place every year.
Crop rotation is one of agriculture's oldest cultural practices. In a home vegetable garden, crop rotation involves changing the location of vegetable families each season. Crop rotation reduces damage from insect pests, limits the spread of vegetable diseases and improves soil fertility.
The vegetable families I use in rotation are Solanaceae (potatoes, tomatoes, eggplant, peppers); Cucurbits (cucumber, squash, melons); root crops (carrots and beets); Brassicas (broccoli and cabbage); legumes (beans and peas); and leafy greens (spinach, lettuce, kale). Ideally the same vegetable family should not be planted in the same place for at least three years. I find this difficult as most of my summer garden is devoted to vegetables in the Solanaceae family, so I'm often rotating crops every two years.
Warm weather in March tempts us to start transplanting tomatoes, peppers, squash and other summer vegetables. But it's not the daytime temperature that matters most; it's the soil temperature. Tomatoes want soil warmer than 60°F before they really start growing. Our Napa Valley soils don't usually reach that temperature until mid-April or May.
Peppers and eggplant want even warmer soil. I have planted tomatoes in early April and again in mid-May and found that the plants start ripening at the same time. So you are not really getting a head start on the harvest by planting early.
Most garden centers sell soil thermometers that will give you an accurate reading. However, if you don't want to spend the money on a soil thermometer, try the “sit down test.” Sit in thin shorts on the bare ground. If you can stay seated comfortably for 60 seconds, then go ahead and plant. Otherwise, your tomatoes will just sit there, too, and not grow. I don't believe the University of California has done any research on this method, and since I have a soil thermometer, I haven't actually tried this myself.
You have a few more weeks before planting, so sit back, relax and think about all those fresh vegetables you will be enjoying this summer.
Tomato Plant Sale: U. C. Master Gardeners of Napa County will hold their sixth annual Tomato Plant Sale on Saturday, April 14, from 9 a.m. until sold out, at 1710 Soscol Avenue, Napa. Find more than 4,000 tomato starts in 28 varieties, from popular heirlooms to new hybrids. These Master Gardener-grown seedlings include varieties suitable for eating and cooking, plus cherry tomatoes of many colors, and early, mid- and late-season varieties. A team of tomato experts will be on hand to answer questions.
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.