If you have ever rooted a cutting in water, you know that plants just love to grow, so I never understood why most of the articles purporting to explain hydroponic growing seemed so complicated. Many lovely plants can be grown indoors and out without complicated equipment or expensive equipment. Except for a few showy flowers, the plants I prefer to grow in water are edible, such as hardy romaine lettuce, tomatoes, peppers, cucumbers, snap beans, as well as purslane, amaranth, chicory and other fast-growing nutritious bitter greens that are delicious sauteed in egg and potato skillet meals.
With just a little attention, all of these plants grow like weeds, but just as people do, they need basic nutrition to survive. This article is not for plant experts who want maxium yield and perfect fruit, but rather I am writing for the entry-level dirt free gardener, especially, the sort of person who loves plants but has not been successful with dirt gardening for whatever reason. For the rank beginner, there are few plants easier to grow than basil, which needs no pollination, will root from a leaf cutting in just 4 days, has an attractive appearance, and makes a most pleasing addition to any pasta dish.
In addition to nutrients, plants need appropriate light levels, temperature, water, and air circulation. I address some of these issues in my gardening blog, referenced in the side links. But in my view the two simplest ways to get started in hydroponic growing are to either buy an AeroGarden from AeroGrow International, or to use your own containers with Hydroton grow rocks to support the plants, and General Hydroponics Flora series liquid nutrients to feed them. The first solution is rewarding, but may cost more than some beginners want to spend. In addition to the cost of the planters, the AeroGarden solution requires continual replacement of the grow lamps, and other necessary supplies, as well as a small amount of electricity. Even with the small AeroGarden 3 planter, a conservative cost estimate for getting started would, in my experience, run about $200 USD. However, with these kits everything is automated and not only do the kits come with wonderful instruction booklets but feeding the plants is as easy as dropping in pre-measured tablets.
By comparison, if you have a sunny window sill and are willing to recycle some juice containers, you can grow perfectly nice salad greens that will be ready for munching in a month or so with an initial expenditure of about $40. The grow rocks can be reused indefinitely, and a 16 oz 3-part set of the Flora series nutrients will last a very long time. Admittedly, a look at some of the grow charts available online or even the instructions on the nutrient bottles themselves may make your head spin. It did mine! But there are really only a couple of things you need to know. If you want to fine tune your growing, the rest can be worked out later.
The first thing you need to know is that the three different nutrient concentrates, Gro, Micro, and Bloom, need to be diluted rather than mixed together in concentrated form. This is because the concentrated minerals bind together chemically when mixed directly. However, I have found that injecting the concentrate from a clean syringe, such as the Ezy Dose Dispenser that mothers use to measure forumula or pet meds, directly into a liter of water works fine. I have syringes with stoppers and fill one with the Grow concentrate, one with Micro, and the third with Bloom.
Young seedlings just starting out do not need a lot of plant food, so for them I use the same mix as for mature plants but 1/4th of the strength. When filling the containers, I just pour the solution in 1/4 of the way to my fill line and fill the rest of the way with water. Please note that unless you have an exceptionally clean source of water, you might want to use filtered water for your plants rather than that which comes out of the tap.
Here is how I mix it:
For vigorous leaf growth, use GRO mixture: Using a 1-liter plastic water bottle (Glaceau Smart Water containers are my favorites) I squirt 3 ml of the GH Flora Series “Gro” nutrients into an almost full bottle of filtered water. I leave a little room at the top so that I can shake the bottle a bit to mix it in. That will be the green colored liquid. Then I squirt in 2 ml of the brown “Micro” concentrate into the bottle and shake again. Finally, I squirt in 1 ml of the “Bloom” and top off with enough water to fill the bottle. With a permanent marker I write “Gro” on this bottle and also 3:2:1 to show the ratio I have mixed.
When you have buds opening or fruiting plants, use BLOOM mixture: Mix as before, but this time use 1 ml Gro, 2 ml Micro, and 3 ml Bloom and label the bottle Bloom 1:2:3. I also draw a skull and crossbones on the bottle to ensure that nobody mistakes my nutrients for fruit juice and drinks them.
These two bottles are all it is necessary to pre-mix, because for general purposes as well as for the transition from growth to blooming, the ratio of 2:2:2 is achieved by feeding your plant with 1/2 gro solution and 1/2 bloom solution. For GENERAL PURPOSE growing, I fill my plant container half full with equal parts of the GRO and BLOOM mixtures described above, and then top off with water. For TRANSITION TO BLOOM growing, I fill the container half full with the GRO mixture and top off with the BLOOM mixture.
A manual ebb and flow planter is nothing more than one container with drain holes in the bottom and containing your plant with its roots held in place by the grow rocks, nestled into another container that is water tight. Once or twice a day, you simply lift the inner container up so that the solution drains down into the outer container. Then lower it slowly and carefully back into the solution, or if you have an extra container, pour it back over the top. To reduce algae growth, it is recommended to put your container inside an opaque cover, which can be anything from an attractive paper bag to an easily made fabric cover. Many of my plants live in nested food containers that I bought at the dollar store for 25 cents each. I cut the covers in half and make an opening for the stems, then snap them back onto the containers to keep the light from shining directly into the top of the planter. I call these my “blue mulch” after the color of the lids, shown in an accompanying photo.