By T. Eric Nightingale, U.C. Master Gardener of Napa County
Gardening and a love for nature is on the rise these days. Many people I know would like to garden more but believe they can't because they live in an apartment or have only a small yard. That's not so. While they may not be able to have massive oaks or cultivate long rows of tomatoes, there are still many ways to grow plants.
The first task in any small space, be it a balcony or yard, is to understand the microclimate. Small yards are often protected from the elements by overhanging roofs and fences, while balconies may be more exposed to wind and rain. Study where sunlight hits your growing space. Spend a day at home watching the patterns of sun and shade as the day progresses.
Even if you have only a small yard, you can increase your growing capacity by using containers. Because they're mobile, you can “go vertical” and put them on shelving or place them in spots that would normally be impractical as a growing space. Think creatively
about where your containers can go.
Most plants, properly cared for, will do well in a container for a while at least, but they may require extra attention to keep them healthy. From personal experience, I recommend firm resolve and objectivity during the plant-selection phase. It can be easy to talk yourself into attempting to grow a cactus on a shady patio or a fern on a baking-hot balcony. In the end, both you and the plant will be unhappy with the situation.
When planting in containers, choose an appropriate potting mix. Soil pulled from your yard or garden will likely be too dense. Commercial potting mixes contain perlite and other porous ingredients that enhance aeration and drainage. If you fill a container with garden soil, the soil will settle over time and become compacted, eliminating pore space.
I have seen container gardens that incorporate old charcoal grills, rubber boots, teapots, pasta colanders and paint buckets. If it can hold soil and you can make a hole in the bottom, it can be a planter. For food production, look for food-safe containers. Certain plastics, metals and even woods may leach small amounts of chemicals. This may not be a problem with an ornamental plant, but it is undesirable for edibles. Otherwise, you are limited only by your imagination. Of course, no one will criticize you for just using terra cotta pots.
Compared to in-ground gardening, container gardening presents a few unique challenges, Plants in containers tend to need more frequent watering. Extreme weather conditions also take more of a toll. Plants in containers are more exposed and can't rely on the warmth and water reserves that soil-grown plants can access. In winter I move most of my potted plants against the house to a provide a little more shelter and warmth. Keeping them well watered and covered with frost cloth is also important during harsh winter nights.
One aspect of container planting that caught me by surprise is the issue of water quality. Over time, minerals in the water build up in the soil, sometimes to excess. This buildup is more likely when a plant is not getting thorough watering. To prevent the buildup, deep-water container plants occasionally, watching for water to flow from the bottom of the pot. This tactic will help flush out excess salts and minerals.
If you have a garden hose fed by an in-home filtration system, you may not experience mineral buildup. But if you are using softened water, you may have more problems than expected. Water softeners add salts, which quickly affect plants. One sign of excess salts and minerals in a container is a whitish crust on the soil surface.
I see this buildup in my houseplants, which are lightly watered and never exposed to rain. Poor plant health also signals soil problems. Excess salts can cause a pH imbalance, which can keep the plant from absorbing nutrients. Adding fertilizers, which contain salts, may only make the problem worse. In fact, fertilizer can also build up in containers and should be occasionally flushed as well.
Container gardening offers flexibility and the potential for creativity. It's a hobby anyone can enjoy.
Workshop: Napa County Master Gardeners will hold a workshop on “Culinary Herbs and Cocktail Garnishes” on Saturday, June 23, from 9:30 a.m. to 11:30 a.m., at Central Valley Hardware, 1100 Vintage Avenue, St. Helena. The workshop will be repeated on Sunday, June 24, from 1 p.m. to 3 p.m., at Yountville Community Center, 6516 Washington Street, Yountville. Plant a plethora of herbs to add color and delight to your plate and to your beverages. Cilantro, basils, thymes, mints and their flowers, nasturtiums, roses, pansies, borage and calendula are only the beginning. Learn to grow these useful plants. Demonstrations and hands-on activities add to the fun. Online registration (credit card only); Mail-in/Walk-in registration (check only or drop off cash payment). To register for the Yountville workshop, call the Parks & Recreation Department at 707-944-8712 or register online.
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.
- Author: Pat Hitchcock and Jim Murphy, UC Master Gardeners of Napa
In a restricted area, such as an apartment complex or a small, confined yard, containers may be the ideal way to raise vegetables. Pot selection, container soil, container positioning, sunlight and heat deflection from walls or fences all contribute to a successful growing experience.
You can use many different kinds of containers, such as wooden planters, clay pots, plastic buckets or even plastic bags filled with planting mix. They must have drainage holes. If you are placing containers on a wooden surface, such as a deck, reduce the possibility of rot by raising the containers on small blocks to allow for air circulation.
Be sure your containers are deep enough for the crop you want to grow. Six to ten inches is sufficient for shallow-rooted plants like arugula, basil, chives, lettuce, green onions, radishes and mizuna. With a deeper pot, 10 to 15 inches, you can try carrots, celery, Chinese cabbage, garlic, leeks, Swiss chard and patio tomatoes.
Go for 18- to 24-inch-deep containers if you want to try beans, broccoli, kale, peas, peppers and short-vine (determinate) tomatoes. A container 20 inches in diameter and 18 inches deep will give you plenty of room for several small lettuces or for one pepper or tomato plant.
The planting medium needs to be both porous and moisture retentive. Because you may need to move your pots occasionally, it also needs to be lightweight. Garden soil is too dense and heavy. A good-quality potting soil will contain compost and nutrients for plants, plus vermiculite or perlite for drainage and peat or coir for holding moisture.
Finding the perfect place for your containers may be the most challenging part. Leafy vegetables such as lettuce need four to six hours of sunlight daily, but fruiting vegetables like peppers, beans and tomatoes need eight hours. An area near a wall that reflects sunlight can be too warm for some plants.
Container soil can get a lot warmer than the ground. Try shading the containers themselves if they are in a warm spot, while allowing the growing plants to get all the sunlight they need.
Container plants require more frequent watering than plants in the ground, and they also need more frequent fertilizing. Most commercial potting soils include fertilizer to get plants off to a good start. After six weeks or so, start fertilizing every other week with a half-strength liquid fertilizer formulated for vegetables or container plants. Nurseries sell organic and inorganic types. Check label directions for the suggested dilution, then double the recommended amount of water to get a half-strength solution.
For container gardens that are always on view, consider the many vegetables that are ornamental. Look for colorful versions of lettuce or Swiss chard, for example. A combination of leafy lettuces, blooming chives and a viola could produce an instant salad mix in a cool location. For the warm season, try a patio-type tomato with sweet basil at the base. Nurseries often have pots with such pre-planted combinations, but it's fun to create your own.
In April, the options for edibles are almost limitless. You can still start some cool-season vegetables, but it is also planting time for warm-season crops. The Napa Count Master Gardener website has several planting calendars in its “Healthy Garden Tips” section. Find that section under the “Gardening Resources” button on the left side of the home page.
Edible container gardens aren't limited to vegetables. Many perennial herbs do quite well in pots. Try thyme, oregano, marjoram and parsley. Edible flowers such as nasturtiums and violas also thrive in containers. Don't let lack of a garden plot keep you from the pleasure of harvesting your own edibles.
Tomato Plant Sale: U. C. Master Gardeners of Napa County will hold their fourth annual Tomato Sale and Education Day on Saturday, April 23, from 9 a.m. until sold out, in a new location at 1710 Soscol Avenue, Napa. Choose from 28 varieties, including heirlooms and new varieties in a range of colors. These healthy, Master Gardener-grown seedlings include types for fresh eating and for sauce.
Workshops: U. C. Master Gardeners of Napa County will hold a workshop on “Growing Tomatoes” on Sunday, April 10, from 2 p.m. to 4 p.m., at the Yountville Community Center, 6516 Washington Street, Yountville. The workshop will focus on techniques for a successful harvest, including soil temperature requirements; tomato types; care and fertilizing; support choices; and integrated pest management. Register with the Parks and Recreation Department at
707-944-8712 or on its web site.
The “Growing Tomatoes” workshop will repeat on Saturday, April 16, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. On-line 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.