Starting Seeds in the Greenhouse: Solanaceous Vegetables


The most popular vegetable in the home garden is the tomato—they’re planted far and wide, from Alaska to Florida and appear on every habitable continent. Gardeners adore the tomato, but many know very little about the other members of family Solanaceae. This may be because tomatoes and their relatives were thought to be poisonous when they were discovered in the New World, despite the fact that native people had no qualms about eating the tempting fruits.

Forward-thinking scientific minds couldn’t shake the relationship between tomatoes and their cousins, the deadly nightshades and mandrake, and a campaign to protect the public began. Books detailing the toxic fruit’s menacing nature were published as far back as the late 1500s—the idea became so implanted in the mind of European gardeners that most growers cultivated tomatoes purely for ornamental purposes until the late 1800s.

A family full of very different plants

A few Solanaceous vegetables fared better in the public view than their red-fruited cousins, however. Potatoes have long been staple foods of many cultures and too many dishes would be extremely bland without the addition of either sweet or hot peppers. The more obscure members of the family, namely eggplants, tomatillo and ground cherries have a small, but dedicated, following and are just as easy to grow in the home garden. Many people don’t recognize them as family, but each of these vegetables is as easy to grow as a tomato plant.

In fact, their needs are so similar that you can usually grow all the Solanaceous vegetables under the same conditions in the greenhouse. These heat-lovers are forgiving, flexible and have been grouped into a stunning array of colors and shapes to fit a variety of needs. Try a few this season to add color and flavor to your garden produce or use them as beautiful edible landscaping plants.

Eggplant – These fleshy fruits appear in a dazzling array of colors, but most people are familiar with the deep, dark purple eggplant. Colors ranging from green to purple, lilac, gold and white are also common on these plants. The beautiful colors and compact nature of the eggplant make it an excellent choice for edible landscaping or container gardening.

Since they’re warm-season crops, you’ll have to start your eggplants indoors in nearly all locations. Sow your seeds six to eight weeks before the last average frost date in individual cells at a depth of about 1/4 inch. They’ll germinate in a little over a week at 85 degrees Fahrenheit (29 degrees Celsius). Eggplants will sometimes germinate in temperatures as low as 60 degrees Fahrenheit (15 degrees Celsius), but they do best between 80 and 90 degrees Fahrenheit (27 to 32 degrees Celsius).

Ground Cherries – The sweetest member of the family, ground cherries were popular with the early European settlers of the United States. Pilgrim families often baked these unusual husked fruits into pies and other confections and they were carried west as America expanded. Many old homesteads have wild stands of ground cherries growing that are descended from seeds shed when fruits were left unharvested. Ground cherries aren’t as domesticated as tomatoes, so are generally much more forgiving, too.

Ground cherry seeds should be started indoors for the best results, at least six weeks before transplanting. As with eggplants, you should plant seeds in individual cells or pots about 1/4 inch below the soil’s surface, but ground cherries will germinate well at temperatures between 70 and 90 degrees Fahrenheit (21 to 32 degrees Celsius) and emerge in six to 14 days. Keep your seeds and seedlings on the dry side, these plants are not accustomed to being pampered.

Peppers – Whether you’re growing hot or sweet peppers, the species is the same. What makes a pepper hot is the concentration of capsaicin, a chemical that the pepper produces as a defense from a common pathogenic fungus called Fusarium. Some peppers developed in drier areas where Fusarium wasn’t a problem, so had a sweeter flavor, while hotter peppers were growing in a wet environment that encouraged fungal growth. If you’re growing your sweet and hot peppers side-by-side, be sure to label them since they can be nearly impossible to distinguish without tasting the fruits.

Peppers of all types should be started indoors in individual cells or biodegradable pots, six to eight weeks before transplantation. They germinate in about a week at temperatures between 70 and 95 degrees Fahrenheit (21 to 35 degrees Celsius) when planted at a depth of 1/4 inch. Resist the urge to move your seedlings outdoors before the soil has warmed to about 60 degrees Fahrenheit (15 Celsius), as cold soil will stunt the growth of these plants.

Potatoes – These root vegetables are a true black sheep among their family, preferring cold temperatures and producing poisonous fruits from their above-ground parts. Instead of plucking the small red berries the plant produces, the potato root is harvested at the end of the growing season. An ample harvest can be produced by a single plant, provided it was well-fed and protected from excessive moisture, which can rot the roots. Cool summers with temperatures below 70 degrees Fahrenheit (21 degrees Celsius) are ideal for potatoes, but they are somewhat flexible in their growing needs.

Potatoes are rarely grown from seed and are instead vegetatively cloned from cuttings of their parent’s root system. Seed potatoes are the very small potatoes that remain after the larger potatoes are harvested at the end of the season, but even larger potatoes can be cut into sections containing eyes and planted back into the garden once the soil can be worked. Wait until the soil is at least 40 degrees Fahrenheit (5 degrees Celsius) to plant your seed potatoes; they should emerge in two to four weeks.

Tomatillo – Less sweet than their husked cousins, the ground cherry, tomatillos are popular additions to salsa and other Mexican cuisine. These husked fruits are citrusy, with crisp flesh and few seeds, and they’re very forgiving to growers. Tomatillos are less domesticated than eggplants or tomatoes and prefer drier soils with only moderate nutrition levels.

Label your plants carefully if you’re going to be growing tomatillos alongside ground cherries—the plants are very similar in appearance and need the same growing conditions. Sow your tomatillo seeds 1/4 inch deep, in individual pots—they’ll emerge in less than two weeks at temperatures between 70 and 90 degrees Fahrenheit (21 to 32 degrees Celsius). If you intend to plant your tomatillos outside, start them six to eight weeks before the last expected frost date.

Tomatoes – Perhaps the most written-about fruit in the modern world, tomatoes captured the hearts and minds of gardeners everywhere after a somewhat rocky start. These plants are grown for their dazzling fruits in colors ranging from white and orange to pink and even deep purple. Plants with green and multicolored fruits have also been developed, as well as those featuring decorative foliage. There’s a tomato for every growing condition imaginable—try a few different varieties this season if you’re a gardener who has never had much tomato success. Start tomatoes indoors six to eight weeks before the last frost date, in individual biodegradable pots. They need less soil covering than the seeds of their cousins, 1/8 inch is plenty. Tomatoes will germinate in about a week at temperatures between 60 and 95 degrees Fahrenheit (15 to 35 degrees Celsius). Keep the seedlings moist, but not overly wet, since they can be very susceptible to Damping Off disease.

Kristi Waterworth
image: Paul Lowry via Compfight cc
Written By
More from editor

NPULP: Straw-pulp for paper making is now a reality

WASHINGTON, D.C. — As a concept, NPulp—the revolutionary straw-pulp technology developed by...
Read More

Leave a Reply

Your email address will not be published. Required fields are marked *