Skip the soil
Can’t garden outdoors? Try out a hydroponic setup, go indoors
Emily Marsh, who lives in Sonoma County, California, always thought the best thing about gardening was the feel of soil on her fingertips. But last year she and her fiance moved to a townhouse with a concrete slab for a backyard. As lockdowns in California stretched into May, and Marsh, 30, read about the surge in gardens, she felt the urge to plant her own. But her only real option was a hydroponic setup.
“I was completely against it at first,” she said, adding that it just didn’t seem like real gardening. Reluctantly, Marsh purchased a unit from Lettuce Grow, a company that sells readyto-grow hydroponic kits. “Now it’s just my favorite thing,” she said.
Interest in hydroponics has surged during the pandemic. For Aerogarden, another company selling hydroponic gardens, sales jumped 384% in the two weeks of March that followed most state lockdowns. From April through June, sales were up 267% year over year.
“It has been a really amazing year for us,” said Paul Rabaut, the company’s director of marketing. A representative for Lettuce Grow said it was on track to do 10 times the sales of last year.
Meanwhile, DIYers are building hydroponic gardens out of PVC pipes and 5-gallon buckets.
When lockdowns began, Vicki Liston started constructing a pipe-based system. She worried about keeping a pandemic garden alive in her arid backyard, but so far the project has been a surprising success, she said.
Compared with traditional in-ground gardening, “hydroponics grows more food in less space with less water and less time,” said Dan Lubkeman, president of the Hydroponic Society of America.
That is, if you get everything right. Hydroponics is about optimizing growing conditions: You must have the perfect amount of light and nutrition available at all times. Nail it, and plants can grow up to five times as fast as they would in soil outside, Rabaut said.
Whether you construct it yourself or buy a kit, a hydroponic garden needs
the following:
Seeds or seedlings. If you’re doing this inside, look for varieties that thrive in containers. This will ensure that none of your plants get so big they take over your whole hydroponic setup.
A reservoir for the nutrient solution, which is made up of all the macronutrients and micronutrients plants need.
An aerating pump for oxygenating your nutrient solution, since plant roots need oxygen too.
A water pump to move water out of the reservoir and onto your plants throughout the day.
Light! More on this below.
A “medium.” Since you’re not using soil, you’ll need something to hold the plant’s roots in place. Many mediums also help keep roots moist between waterings. Lubkeman recommends a material called rockwool for beginners.
As with most hobbies, you can spend a little or a lot. Originally, Marsh wanted to go the cheap route. Setting up a medi
um-size DIY system with a few buckets and an aquarium pump can set you back less than $150.
But Marsh worried about getting everything working correctly. Lettuce Grow’s container is made from recycled plastic, and for Marsh, that tipped the scales toward buying a premade kit, even if units start at $348 — no lights included.
Once your setup is set up, you may see seeds sprouting within three days, though some plants take longer. By two weeks, your seedlings should start to look like real plants. Which is when Liston realized that her hydroponic experiment was not going quite right. Just a few weeks in, her plants were dying.
It turned out her tap water was too alkaline. A pH buffering solution fixed the problem. (Water testing between 6.5 and 7.0 on the pH scale is considered ideal.) A setup like AeroGarden will tell you when you need to add fertilizer or adjust the pH of your water. If you built your own operation, you’ll need to remember to add nutrients and check the pH of your water (using testing strips) weekly.
“It’s been fantastic,” Liston said, adding that once she got her light, pH and nutrient levels dialed in, “it just exploded.”
If some plant nutrients are good, more would be better, right? That’s not at all the case, Liston said. So far, she has managed not to overfeed her plants, but too much plant food can result in dead or severely damaged plants. How often and how much you’ll need to feed depends on the type of nutrient solution you’re using. Read the directions on the bottle.
You may be able to grow lettuce or herbs in a sunny window, but as days get shorter, investing in a full-spectrum grow light is worth the expense. These lights provide the same range of light as the sun, and you’ll see faster growth, Lubkeman said. In Liston’s case, adding a light and moving her plants next to her sunniest window resulted in a noticeable change in their productivity.