Just in time to screw up those New Year’s diet resolutions, more lettuce recalls were announced. Most of these are due to contamination, either by salmonella or listeria, and can be blamed on either the way lettuce is grown or how it is processed. Disease-causing bacteria can spread easily during large-batch washing/processing, leading to outbreaks and recalls. This ultimately means shortages and higher prices for everyone. (Well, at least those of us who eat lettuce.)
Anyone who’s attended my gardening talks has heard about my fondness for hydroponic supply stores. They have a good selection of higher quality growing supplies, and the vibe is a bit different from the usual garden center.
Now that marijuana cultivation has become (relatively) legal, hydroponics has also gone mainstream. Even Costco offers a countertop hydroponics setup for growing your own lettuce and herbs.
If you have tried growing lettuce just to have it devoured by the local bunny population or ruined by slugs and snails, you might consider trying out one of these little hydroponic units. If you want to grow more than just a few herbs and lettuce plants, you could set up a larger unit in your garage. Setting up your entire house with hydroponics, however, may attract some unwanted attention from the local authorities.
So, what makes hydroponics so unique? It is a soilless system in which plants are grown in either a liquid nutrient solution or an aggregate substrate immersed in a nutrient solution. This means that you can control the nutrient content precisely, hopefully resulting in healthier plants. Marijuana growers prefer this method because they can control and maximize flower budding and THC production. We’re just interested in lettuce that doesn’t have slugs and won’t give us food poisoning.
Romaine, butterhead, bibb and other loose-leaf varieties are well suited for hydroponics. They will grow quickly, and you can remove the larger, outermost leaves while leaving the rest of the plant to grow. This is referred to as the “cut-and-come-again” harvest method. Whenever I try to do this with garden-grown lettuce, I always end up with bits of weed leaves and slugs that must be removed. This is time-consuming and gross.
Hydroponically grown lettuce (and other crops) grow quickly if they have enough light and the proper nutrients. There are special nitrogen-rich grow formulas made just for lettuce and leafy greens. You don’t want to use “Super Bud Juice” for your lettuce.
Once your seeds have germinated and produced their first set of true leaves, they can get 12 hours of light per day. Of course, this can be adjusted according to the plants’ response. If they look stressed and develop brown leaf tips, shorten the light exposure. If they look scrawny and leggy, increase the light.
Hydroponics does require a bit more attention since you oversee watering, feeding, and light exposure. Some of the newer countertop units are partially automated with light timers and low-water level alarms, but ultimately you have to play the role of Mother Nature.
Have questions? Email gardening@scng.com.
Looking for more gardening tips? Here’s how to contact the Master Gardener program in your area.
Los Angeles County
mglosangeleshelpline@ucdavis.edu; 626-586-1988; http://celosangeles.ucanr.edu/UC_Master_Gardener_Program/
Orange County
ucceocmghotline@ucanr.edu; 949-809-9760; http://mgorange.ucanr.edu/
Riverside County
anrmgriverside@ucanr.edu; 951-683-6491 ext. 231; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern@ucanr.edu; 909-387-2182; http://mgsb.ucanr.edu/
