Garden Talk: July 1, 2010
From NGA Editors
A Pinch of Salt for Tasty Tomatoes?
A tomato ripe from the garden needs little more than a sprinkling of salt to make it a mouthwatering treat. But could a pinch of salt while it's still in the ground make it even tastier?
According to Rutgers University soil fertility specialist Joseph Heckman, that might just be the case. He has looked at the ways that various soil nutrients influence the development of flavor in tomatoes. For example, potassium's role is to help move water into the cells of maturing fruits, so if you want juicy tomatoes, you need to make sure this nutrient is present in adequate amounts. Sulfur is needed for the formation of the organic compounds that give flavor to tomatoes. It is likely to be deficient in sandy soils that are low in organic matter, a problem that can be remedied with applications of compost or gypsum. According to Heckman, unrecognized boron deficiencies are not uncommon. Research in North Carolina demonstrated that adding boron reduced the incidence of fruit cracking and uneven ripening.
Which brings us to sodium, present in sodium chloride, better known as salt. In the past, sodium was found in many of the fertilizers used in vegetable production, such as sodium nitrate, but Heckman notes that most nitrogen fertilizers used today contain no sodium. A study in Israel suggested that this lack of sodium in the soil might have a detrimental influence on tomato flavor.
So he conducted a small trial of his own at Rutgers. One group of Jersey tomatoes received a one-time top drench of Atlantic seawater during early bloom, while the control group got tap water. After both groups ripened, a blind taste test was held- and the salted tomatoes won hands down!
Of course, this was a very small trial and excess sodium in the soil can cause problems for plants and harm soil structure. But if you are an investigative sort of gardener, it might be interesting to experiment with some container-grown tomatoes and see if you find that a little salt results in a tastier tomato.
For more information on Dr. Heckman's experiment, go to: Can Soil Fertility Improve Tomato Flavor?.
Getting the Lead Out
As interest in eating locally grown and organic foods increases, so does the number of urban food gardens. Whether in backyards or community garden plots, more and more urban residents are trying their hand at growing fruits and vegetables. While it's great to see so many folks greening our cities and improving their nutrition with gardens, it's important to keep in mind some cautions specific to many urban environments.
Because of their history of use, soils in urban, commercial or industrial areas are more likely to contain lead, cadmium, arsenic and other contaminants than those in suburban or rural areas. For example, lead, although banned from these uses today, in the past was a common ingredient in paints and was used as a gasoline additive, while cadmium accumulated in soil from the burning of coal and garbage.
To help gardeners in urban areas raise safe crops, the University of Minnesota Extension Service and the Cornell Waste Management Institute have both put together excellent publications that offer information on how to figure out if contamination is present and what the best gardening practices are for reducing the risk of exposure to toxic substances in the soil.
A soil test for contaminants is the first step. Tests for lead, cadmium and arsenic are relatively inexpensive; uncovering some of the history of a site may indicate if other tests are in order. Even if some contamination is discovered, there are strategies that can still allow for a healthy garden, such as using raised beds, increasing organic matter in the soil and washing and peeling root crops and the outer leaves of leafy greens before using.
For more information on safe urban gardening, check out the information in these two publications: Urban Gardens and Soil Contaminants: A Gardener's Guide to Healthy Soil and Soil Contaminants and Best Practices for Healthy Gardens.
More and more gardeners are turning to native plants for their landscapes. One such choice is the adaptable inkberry (Ilex glabra), a broad-leafed holly with glossy, deep green leaves and white or black berries on a rounded shrub that is found in the wild in coastal plains and swamps of the east coast. As a landscape plant, it does well in a variety of sites, tolerating not only damp soil and partial shade, but dry soils and seaside conditions as well, and is reputed to be deer-resistant.
While the straight species can grow as large as 8' tall and 10' wide, a number of cultivars of more restrained growth have been developed that work well as foundation shrubs, mass plantings or hedges. Recently, as reported in the March 2010 issue of American Nurseryman magazine, Longwood Gardens in Kennett Square, PA completed a multi-year evaluation of a thirteen of these cultivars to assess their growth habit, susceptibility to winter injury and overall attractiveness.
Four cultivars stood out as plants with exceptional landscape merit. 'Densa', a 4-8' tall cultivar with a dense, uniformly rounded growth habit, lustrous, deep green foliage and good resistance to leaf spot took first place in the evaluations. 'Bright Green', with small, bright green, boxwood-like leaves came in second. Next was the widely available 'Shamrock,' a 3-5' tall and wide shrub with a very full, rounded habit and small, shiny leaves. Completing the top four was 'Nigra,' a fast-growing cultivar that retained its lower leaves well and is a good choice for gardens in the south.
Inkberries are hardy in USDA Zones 5-9, although some cultivars, such as 'Densa,' and 'Nordic,' do well in zone 4. And, as an added bonus, inkberry is a great food and habitat provider for beneficial insects and butterfly larvae, a good source of nutrition for struggling honeybees and its berries are an excellent winter food source for birds. Who could ask more from a plant?
Finding Farmers Markets
We can all benefit from the taste and nutrition of garden-fresh fruits and vegetables. But if you can't grow your own, or you don't have the space to grow all you need, a farmers market brimming with just harvested produce can provide a healthful bounty. And while you're filling your market basket, you'll also be supporting farmers in your area and the local economy.
To help you find farmers markets in your community, the USDA has put together a searchable on-line database on their Know Your Farmer, Know Your Food website. You can search more than 4800 markets by market name, city or state, and find out whether they accept WIC, SFMNP and SNAP vouchers, and credit or debit.
The individual market entries list the address, contact information, hours and dates of operation, types of foods and goods offered and whether or not organic produce is available. The site also has links to tips for shopping at farmers markets and information on joining a community-supported agriculture (CSA) project, as well as menu planning suggestions and recipes using all the great produce you got at the market.
For more information on locating a farmers market near you, go to: Know Your Farmer.