JSS Advantage -- February 2011

February is the month when the days get long enough for plants to start or resume growth. It may still be bitter cold, and there may be snow on the ground, but the market farmer starts feeling the irresistible pull of a new growing season. If you have a greenhouse or hoophouse, you know it's time to get your hands dirty. In this issue of the JSS Advantage, we'll cover growing vegetable transplants to sell, planting cold-tolerant crops in the high tunnel, and exploring resources for urban farming.

Growing Vegetable Transplants for Sale

If you grow your own veggie transplants, it's a simple matter to grow extras for sale at farmers markets and farm stands. Customers will be pleased to see unusual varieties not available from the big-box stores, especially those recommended by a local farmer.

Transplants for sale should be handled slightly differently than those for the field. They should be larger than those you would transplant outside, and grown in individual pots or cell packs. As a result, transplants for sale will require more time in the greenhouse, larger cells, and sufficient fertility to keep them thriving.

Large plants such as tomatoes and peppers are commonly grown in 3" or 4" pots. Some growers find that plants that don't sell at that size can be potted up into larger containers as big as a gallon pot and sold later in the season when they are flowering and fruiting. Small plants such as lettuce and leafy herbs can be grown in four-cell or six-cell packs.

Because of the growing popularity of organics with backyard gardeners, it may be wise to grow transplants according to organic standards, whether or not you're certified organic. That includes using growing medium and fertilizers that are approved for organic use. Johnny's 512 mix is a custom-blended mixture of peat, perlite, and compost that is designed to carry seedlings through to transplant size. If you prefer to mix your own potting medium, recipes are available at the ATTRA website. Eliot Coleman's book The New Organic Grower also provides valuable advice on making your own.

Research at the University of Kentucky showed that fish emulsion can be used to fertilize organic tomato and pepper transplants. In fact, transplants fertilized with fish emulsion were much bigger and healthier than those grown in a soilless mix amended with composted manure or worm compost.

The goal of transplant production should be healthy, rapidly growing plants. Here are the most common factors that cause plant growth to be checked, according to the Ball RedBook. Be sure they don't occur in your greenhouse, and you'll have a profitable crop of transplants to sell in spring.

1. Poor physical condition of soil. The growing medium must be loose and porous to provide adequate drainage and oxygen to roots. Potting mixes with small particle size tend to get tight and hard.
2. Seedlings must be transplanted before they get root-bound; in most cases, that's when they have their first pair of true leaves.
3. Too low or too high nutrient levels. Follow the label instructions for fertilizing transplants.
4. Diseases. Root rots and viruses can go undetected until it's too late if you're not watching for growth slowdown.
5. Insects. Aphids, spider mites, whiteflies, and fungus gnats are common greenhouse pests that should be monitored.
6. Lack of water. Transplants must be watered thoroughly and frequently. Water properly, as this tends to be one of the most common greenhouse errors.
7. Too cold. The ideal temperature depends on the crop, but remember that unnecessarily low temperatures will check plant growth.

What Can You Plant Now?

Eliot Coleman writes in The Winter Harvest Handbook that once day length reaches 10 hours, plants will start growing rapidly. By mid-February, virtually all of the U.S. has more than 10 hours of daylight. In theory, we could all start growing this month! But, of course, temperature is also a factor that affects plant growth and in quite a bit of the U.S., the temperature is still too low.

Growers with hoophouses, however, know that conditions are much warmer under that single layer of greenhouse poly. And if they have a low tunnel inside the hoophouse, they know it's positively spring-like some days in February. And so it does become possible to start growing this month.

The key to hoophouse planting this month is to choose crops that can tolerate cold temperatures and light frosts. Most can be direct seeded now and they will grow as soon as the soil temperature is warm enough for germination. With that inner layer of row cover held above the young plants, temperatures will be warm enough to keep them thriving.

Crops that can be seeded in late winter in the hoophouse: arugula, beets, carrots, chard, kale, lettuce, mustard, parsley, peas, radish, salad greens, scallions, spinach, and turnips.

Here's the seeding schedule used by Adam Montri, hoophouse outreach specialist at Michigan State University.

The Ultimate in Local

In cities and suburbs all over North America, urban lots and small backyards are being transformed into productive mini-farms. Urban agriculture is fast becoming the biggest trend in market gardening this decade and for good reason. The benefits of urban farming are numerous, ranging from greater food security to nutrition education to community building. The challenges are plentiful, too, and in this issue of the JSS Advantage, we'll tell you about resources to help with the development of an urban farm.

The Food Project in Boston is one of the earliest and most successful urban farming ventures in the U.S. (One of The Food Project's urban gardens is featured on the cover on the 2011 Johnny's catalog.) The organization's mission is "to create a thoughtful and productive community of youth and adults from diverse backgrounds who work together to build a sustainable food system." To that end, The Food Project employs teenagers in multiple gardens in and around Boston to grow food for a CSA, farmers markets, and food pantries. It also provides assistance to city residents who want to grow their own food.

One of the biggest issues for urban farmers and gardeners is the presence of lead in urban soils. Researchers at Wellesley College tested 141 backyard gardens in two Boston neighborhoods and found that 81% of them had lead levels considered dangerous by the EPA. In collaboration with Wellesley, The Food Project experimented with different ways to remediate the lead contamination. The organization has found that amending with compost and building raised beds are the most cost-effective and efficient remediation techniques.

The Food Project has many free resources available on its website, including an Urban Agriculture Manual that details how the project creates healthy soil, intersects with the community, works with young people, and plans urban food lots.

Growing Power is another long-established urban farming project, and it gained well-deserved recognition in 2008 when its founder, Will Allen, was named a John D. and Katherine T. McArthur Foundation fellow and awarded a "genius grant" for his work. In addition to the programs it operates in Milwaukee and Chicago, Growing Power offers national outreach through its Commercial Urban Agriculture Training.

Issues that face urban farmers include zoning codes, business licenses, nuisance and noise laws, water access, and neighbors. Writing in Growing for Market, Katherine Kelly, director of the Kansas City Center for Urban Agriculture, advised growers on what to expect when creating a new farm from an urban lot.