Yes, you can grow wheatgrass in plain old water. You can also grow it in organic soilless potting mix. compost, coir, and of course, real soil. While it may be cheaper and less messy to grow wheatgrass the hydroponic way in jars or glass bowls, it will have less nutrition as a plant. Less good stuff going in always means less good stuff coming out.
Now it is true that a seed has stored nutrition to provide the fragile new life with what it needs to develop the beginning of a root system, and those adorable little newborn leaves. Once the mature leaf shape forms though, it needs another source of nutrition to have the energy to become a robust young plant. Many hydroponic gardeners starve these immature plants to coax them to develop a stronger root system, but the goal for that type of crop is completely opposite of something like wheatgrass.
It is more than a sprout that you’re after, which means your tray or pot does need a source of food to produce what you’re after in terms of benefits. Water soluble seaweed a.k.a. kelp is just the kind of instantly available food your young forest of grass needs. Now it wouldn’t make much sense to add a fertilizer source when using the sprout jar growing method since you’re just going to through it down the drain every day. Additionally, as one veteran wheatgrass user puts it, to keep yourself in a good supply for daily juicing, you’d need a heck of a lot of jars and would have to invest a lot of time in rinsing, draining, and refilling them all.
Soil growing wheatgrass is much easier, and takes up a lot less space and time. Then comes the question of what kind of soil? With a crop that is so fast to reach the harvest stage, some people swear by the cheapest potting mix available, but this will present you with growing issues.
Commercial potting mixes – organic or otherwise, are predominately peat moss, which is on the wrong end of the pH scale for your red winter wheat’s preferences. Sure, they add lime in an attempt to correct this, but it’s not stable. The pH will change from batch to batch, and even vary from one spot in the bag to another. Wheat is prone to mold if the pH isn’t on the alkaline side. It’s also prone to mold grown hydroponically. Both situations can be lessened with air circulation with a fan. However, that acidic pH will definitely affect the flavor of your juice, along with stressing the plants out. How’s your positive energy when you’re stressed? Are your productive?
Better juice from happier plants. Be sure they have an indirect source of sunlight or fluorescent grow lights. They need the light to create chlorophyll.
Using coir gives your wheat seed a friendlier environment, but it is an inert material, and all nutrition, minerals, vitamins and what-not your wheatgrass has to work with will come from fertilization you provide. If it’s lopsided nutrition for the plant, it will not be as high in beneficial content for you either.
Organic compost bought in bags can contain worm castings, guano, and even chicken manure. Some people have an aversion to growing their juice supply in this kind of medium, even though it is composted. BUT, this is the food source the wheat plants need! If you look for organic compost labeled for growing food, you’ll be fine. Straight compost dries out faster than compost mixed with topsoil.
You can’t beat real soil. It has over 100 beneficial elements, and the wheatgrass juice you’re after contains 90 of them. You can use soil from your yard, but sterilize it in the oven first (160-180°F). Potting soil in bags is faster and easier. Mix it for good drainage though and looseness to help the wheatgrass grow quickly and thickly. The best recipes will be 5 parts topsoil, 2 parts coir, and 1 part sand – or – 50-50 topsoil and compost.
Wheatgrass grown in soil is richer in color than any other method. Look at the difference in this video: