If it's January, then there are likely to be one or more seed catalogs showing up in the mail, either as old-fashioned paper magazines or as digital catalogs via email. Just like seeds, the catalogs are full of possibilities for your vegetable or flower garden. Unlike the seeds, though, these catalogs are often full of hype. One catalog that came to my house lists nearly 100 tomato varieties, and here is a sampling of the descriptions: “tops the chart in sweetness,” “intriguingly complex flavor,” “gorgeous and succulent,” “unparalleled quality.”It takes a bit of discipline to look beyond the hype to assess whether a particular variety is likely to succeed in your garden. Let's look instead at some of the words used by seedsmen that are more fact than fancy.

Seeds offered for home gardeners come as two types: open-pollinated or hybrid. Open-pollinated seeds are produced by natural processes such as insects, wind, or self-pollination. Hybrid seeds are produced by breeders cross-pollinating two open-pollinated strains of a plant to produce a hybrid plant with specific characteristics such as disease resistance, higher yields or early maturation. In catalogs hybrid seeds are often indicated as “F1.” Many open-pollinated seeds are also “heirloom” seeds, developed over many years by natural selection rather than the efforts of breeders. Unless you intend to save seed from the plants you grow, it doesn't matter whether your seeds are hybrid or open-pollinated. Sometimes hybrid seeds are a little more expensive but may be worth the extra cost for their desirable traits.

Many catalogs list some or all of their seeds as “organic.” If listed as organic, then the seed has been certified to have been grown under organic standards. The catalog should tell you which organization has provided the certification. Otherwise, you can assume that the seed was grown in conventional ways.

You will want to understand the growth habit of the plants you grow from seed. If you are looking for plants to grow in small spaces, you may want plants that are compact, suitable for growing in containers, bush-type or, in the case of tomatoes, “determinate.”Seed described with these terms will develop plants with more restrained growth habits than other varieties. These plants also are more likely to have a shorter life span than their larger cousins. For example, bush beans grow compact plants that usually need no support and produce beans over a shorter period of time than pole beans. This could be advantageous if you have limited space, are too busy to set up a trellis, or want all your beans to be ready to harvest in a short period of time.

On the other hand, vining plants have advantages too. Pole beans will probably produce beans over a longer harvest period, be easier to harvest,and over the season produce more beans per plant than a bush plant. Vining plants such as cucumbers can be grown on trellises to save space in a cramped garden. ‘Indeterminate' tomatoes are the ones that keep on growing all season long and may set several flushes of fruit.

If you are growing vegetables from seed, you will be anxious to get your first harvest. Seed catalogs will give you an estimated “days to maturity.”For varieties that are normally directly seeded in the ground, such as lettuce or beans, days to maturity is counted from the date of seeding. However, for plants such as peppers or broccoli that are transplanted, days to maturity starts from the transplant date. You should also be aware that “days to maturity” refers to plants grown under ideal conditions. Since every growing season is variable, your harvest may not start on the seed catalog's time schedule.

Varieties may be described as early, mid or late season. These terms refer to the time a variety produces relative to other varieties. If you want to have tomatoes early in the summer as well as late into fall, you might choose different varieties that mature early, mid-season and late. You set out all the plants at the same time in the spring. The early varieties start producing first, and by the time they slow down, the later varieties come into production.

Not every vegetable or flower thrives in summer weather. It is helpful to know if a variety prefers cool or warm weather. Seed catalogs do not necessarily identify plants as “cool season” or “warm season” plants, but you can get an idea from the descriptions. Plants described as“tolerate heat” are often plants that prefer to be grown when it is cool. Some varieties of lettuce are often described this way and will produce edible leaves in warm weather, but the quality is not as good as lettuce grown in early spring or early fall and winter. Cool season plants are also often described as tolerating frost. If the catalog mentions planting in warm soil or after danger of frost, you know you're dealing with a warm season plant. These plants may also be described as “heat-loving” or “stands up to hot weather.”

Reading the seed catalogs is a lot of fun, but beware of fanciful descriptions of taste and beauty. Focus instead on the measurable attributes of the plants, and decide for yourself if your harvest is fabulous, fantastic, and wonderful. It likely will be if you grow it yourself.

Workshop: UC Master Gardeners of Napa County will host a workshop on “Garden Planning” on Sunday, January 24, from 1 p.m. to 3 p.m. at the Yountville Community Center, 6516 Washington Street, Yountville. At a loss about what and where to plant in your own garden? Aren't sure of the factors that lead to a thriving yard? Home gardeners will examine their own garden's microclimates and receive tips and direction for choosing sites and plants suited to their particular locations and microclimates. To register, call the Parks and Recreation Department at 707-944-8712 or visit its website.

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.org/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.