Home & Garden

The 101 on hydroponics

Hydroponic gardening may sound alien. Indeed, NASA scientists have embraced it as a food-producing avenue for deep-space exploration.

For Earthlings, hydroponic gardening is simply growing indoors and in a nutrient-rich water solution. Soil is not involved.

As more open land succumbs to development, growing indoors in a controlled environment is emerging as a more viable and sometimes necessary option for home gardeners. Hydroponic gardening is ideal for urban dwellers in condos, townhouses and apartments and also allows everybody to grow warm-season fruits and vegetables year-around.

Hydroponically grown plants tend to grow faster, can be placed closer together and often have higher yield because nutrients and oxygen are more readily available in water than soil, where roots have to work harder. Plants grown hydroponically also use less water (reduced evaporation and no runoff) and pesticides.

What can be hydroponically grown? Tomatoes, cucumbers, lettuce, peppers, house plants, medicinal and culinary herbs and flowering plants all are popular choices. Just about any plant that can be grown in soil and outdoors can be grown in water and indoors, although some are more challenging.

Chances are the tomatoes you’ll eat in January will have been grown in water, not soil. According to the Progressive Gardening Trade Association, more than 95 percent of commercial greenhouse-grown vegetables in the United States and Canada are hydroponically grown.

Robert LaGasse, executive director of the Progressive Gardening Trade Association, says interest in hydroponic gardening has grown significantly among home hobbyists, but he can’t cite statistics.

“That’s anecdotally speaking,” he said. “Statistics truly don’t exist. In some states you can’t even ask what the customer is using it (growing equipment) for. And it won’t change until the states quit fighting with the federal government (over medical marijuana).”

Home gardeners considering setting up a hydroponic system in a spare bedroom, closet or greenhouse should be aware that the hobby demands an initial financial investment for special equipment, patience and attention. Lapses in attention often spell failure.

“Soil is more forgiving,” said Gabe Garcia of the Greenhouse Garden Supply in Carmichael. “With hydroponics you have to stay on top of everything, cleanliness, pH and nutrients.”

Hydroponic gardening is at the mercy of power sources, pumps and timers. Leaving plants unattended for any length of time is a recipe for disaster. Vacations and long weekend outings require a trusted friend or family member to babysit the crop.

“If a fuse blows, if the power goes off, everything wilts,” said Garcia.

There are several types of hydroponic systems. A basic starter kit-in-a-box will include a reservoir, pump, growing medium, and nutrients for around $60.

Growing mediums like Rockwool (cubes of spun volcanic rock and limestone fibers) and clay aggregate anchor and help aerate roots. So-called “true hydroponic” systems don’t use soil-less mediums and roots are only touched by water. Water pumps circulate the water and deliver nutrients to roots, while air pumps allow for oxygenated water and the movement of nutrients.

Growing with available light from a south-facing window is iffy, so you’ll likely need a lighting fixture. High Intensity Discharge (HID) or T5 fluorescent lighting systems are the two most popular options. Energy cost for running lights depends on bulb wattage, the length of lighting cycles and how many lights are needed. Your electric bill will increase.

Intense lighting generates heat that can wilt plants, so ducting that vents outdoors may be required, too. Lighting and venting can increase your total startup cost to $800-$1,000.

Accessories and extras are as many and varied as outdoor gardening. For instance, you may want to add a reverse osmosis system, which is a series of filters that extracts contaminants and minerals from tap water. The result is pure water for growing. A decent ROS can be purchased for about $200.

To save money, you can buy used equipment, make your own system or keep the garden small, simple and less costly.

Unlike outdoor gardening, hydroponic gardens don’t have weeds. There is no tilling, mulching, heavy sacks of soil amendments and wheelbarrows, either. But like outdoor gardening, pests and disease can be troublesome.

“Mealybug, aphid, whitefly, spider mites and fungus gnats are pests indoors,” said Curtis Jones, manager of Green Fire, a Sacramento business that specializes in hydroponic and organic gardening supplies. “Unfortunately, there are no natural predators.”

Both organic and synthetic (chemical) pesticides are used to control pest and disease problems. A serious outbreak of either spreads rapidly in the close quarters of a hydroponic garden. Synthetics work faster, which is why they’re more popular with hydroponic gardeners, according to Garcia of the Greenhouse Garden Supply. However, he added that organic products and methods are being used.

Powdery mildew is a common disease, especially with cucumbers, squash and melons, said Jones of Green Fire. Excessive humidity and lack of cleanliness trigger most diseases. Other diseases that may be encountered include botrytis (gray mold) and verticillium and fusarium wilts.

A basic knowledge of what plants need for healthy growth is needed before embarking on growing indoors. The Internet is full of hydroponic gardening information and there is no shortage of books on the subject. Study and learn before you make an investment. Visit the many retail outlets in the Sacramento area for expert advice.

“Hydroponics can be intimidating,” said Gary Hannon, manager of the Greenhouse Garden Supply. “Some people are scared just hearing the word. Patience is important. You may not get it right on the first try, but keep trying and keep it simple.”