Succulent Edible Shoots

by Dr. Lynette Morgan

2009-05-01

Many of us are well familiar with the trend in microgreens, which has swept worldwide through fine dining restaurants, farmer’s markets, produce stores and the health food industry. These tiny packages of nutrients, antioxidants and chlorophyll are perfect miniatures of their adult parents and most have subtle and delicate flavors to match. However, within the vast array of microgreen species there is a group referred to as the ‘edible shoots.’ Comprising the most well known of all microgreens – wheatgrass, this category also contains pea shoots or tendrils, mung beans and lentils, corn and sunflower shoots or ‘greens.’ These edible ‘shoots’ are typically larger and taller than most of the other microgreens and some, such as pea and corn shoots may be cooked in stir-fries, soups and other dishes.

While most of these edible shoots can be purchased prepackaged and ready to eat, there are some major advantages to growing these yourself and harvesting just before use. Edible shoots contain many vitamins, including vitamin C or ascorbic acid, the levels of which are known to decline the longer the greens are stored after harvest. What is even more interesting is that these shoots have much higher concentrations of vitamin C and health promoting phytochemicals when grown in the light, compared to sprouts, which are typically grown in the dark. So indoor gardeners with a sunny window or grow lamp can take advantage of even the tiniest of spaces to produce healthy fresh shoots year round.

Growing Edible Shoots

Hydroponic methods provide a huge advantage when it comes to microgreens and shoot production. The old ‘dirt filled tray’ method of growing baby greens and shoots doesn’t provide the cleanliness, quality or grit free product that hydroponic methods can. Use of hydroponic nutrients can give many shoots such as wheatgrass, which is grown for a longer time, a real boost in mineral content - a bonus in any type of health food. Hygiene also needs to be considered; strict guidelines are used in the commercial production of microgreens, sprouts and shoots and these should be followed by anyone growing these at home. Cooled, boiled water can be used for soaking seeds and germination trays should be cleaned with bleach between crops. If mould or bacterial diseases continually appear, the seed may need to be surface sterilized before sowing with a 10 per cent bleach solution and rinsed well with water. Growth of certain moulds on germinating seeds can pose a health risk, so any shoots with fungal development should not be harvested or eaten.

Since edible shoots are tender young seedlings they need a growing media that will hold sufficient moisture and oxygen around the seed without water logging or drying out frequently. This substrate also needs to be sterile, as many pathogens like to attack young plants in vulnerable stages of development. Grit or particle free is also another requirement – sunflower seeds in particular, when sown at high densities, tend to throw up media particles, which can stick to the seedlings and contaminate the final product. These days there are some great grow pads and mats specifically designed for microgreen and shoot production, which are a real bonus to small indoor gardeners and commercial growers alike.

Light is also essential for shoot production – or at least for green shoot production. Pea and corn shoots can be grown as the traditional ‘green’ type or the blanched ‘yellow or golden’ type. Green shoots are grown in full light, while the yellow or blanched product is grown in darkness. Obviously the green shoots contain chlorophyll, the green pigment responsible for photosynthesis in plants, which is consumed as a health supplement. However, blanching shoots by growing them in darkness not only gives an interesting and contrasting color, it also provides a milder flavor and softer texture. Light for shoot production doesn’t need to be intense; young seedlings need much less light than mature plants which means these greens can be grown near a window or under small lamps. Photoperiod is not important, so continual low-level light is often used to help speed growth. There may be some benefit to using either natural light or full spectrum lamps for microgreens and shoots as it is not yet known how different wavelengths of light might influence the bio-active compounds and health promoting phytochemicals that these tiny plants contain.

Wheatgrass

Wheatgrass shoots are an old favorite and still growing in popularity as a health promoting juice. Wheatgrass shoots are grown for longer than other shoots and for this reason they benefit from additions of dilute, well-balanced hydroponic nutrient as food reserves in the wheat grain are exhausted long before the wheatgrass is harvested. Dilute nutrient (EC .4 to .5 mS cm-1) can be applied daily, once germination has occurred. Selection of one of the many nutrient products that contains minerals beneficial to human health (selenium and chromium) can also help boost the nutrient content of wheatgrass. Full spectrum lamps or reasonably strong natural light also help boost vitamin and chlorophyll content in densely grown wheatgrass. All these factors mean that home grown wheatgrass consumed immediately after harvest and grown with consideration for what influences levels of vitamins, minerals and phyto active compounds in the shoots, should be superior to a bottled or packaged product.

Sunflowers

Sunflower shoots are becoming increasingly popular as a salad green and are easily grown indoors. The advantage of sunflower shoots is not only are they quick to germinate, but they also produce a succulent, slightly nutty flavored shoot. Furthermore, the cotyledon or first seedling leaves of the sunflower are large and thick compared to many other microgreen species. Given that the cotyledons have been shown to contain the highest levels of bioactive compounds, large seedling leaves are a benefit for those interested in the health benefits of microgreens. Sunflower shoots are high in chlorophyll, and as germination occurs, seed fats are converted to essential fatty acids and carbohydrates, proteins are converted to amino acids and vitamin levels increase significantly.

Sunflower seeds grown for ‘greens’ need to have the hull (the hard outer seed coat) intact. As with all microgreens, the seeds need to be clean and untreated with any fungicides or germination compounds. Seeds should be washed several times in clean water, and then soaked for 24 hours. After draining, the seeds can be spread over a moisture retentive, sterile media in shallow trays. For shoot production, where the tiny plants are only grown for six to seven days, the seed can be layered thickly – two to three seeds deep is fine, so as to make the most use of space and light. Ideally sunflower shoots should develop an elongated, white stem and using a high seeding density helps ensure this. Ideal temperatures for sunflower germination are 75 to 83°F, which are usually obtainable indoors in a warm position, or on a heated seed pad underneath the germinating tray will speed growth in winter. Sunflower shoots are harvested as soon as the cotyledons or seedling leaves have fully expanded, but before the first true leaves can be seen developing as these have a more bitter flavor. The shoots are cut at the base, and any seed husks still attached to the top of the plant are brushed off at harvest.

Corn Shoots

Corn shoots have a surprising flavor and sweetness – like a mild sweetcorn kernel with a hint of candy aftertaste. The most popular type of corn shoot is grown from popcorn, although sweetcorn can also be used. Corn shoots can have a slight degree of toughness and are best grown rapidly at warm temperatures and light, which is not too intense to keep the shoot tall and succulent. Seed is prepared in a similar way to sunflowers, by washing and rinsing, then soaking for 24 hours before sowing onto sterile seedling mats. Corn needs warmth – 78 to 90°F for rapid germination as cool temperatures will slow growth and can cause the seed to rot. Seed density can be high as the shoots will push upwards and grow well even if sown two to three kernels deep. Shoots are best harvested fairly young before they develop any toughness; usually this is only four to six days post germination. Yellow corn shoots are grown in total darkness and harvested when around four inches tall – these are sweeter and tenderer than green shoots.

Pea Shoots and Tendrils

Pea shoots have long been used as a garnish, addition to salads and in various cooked dishes, and these are one of the most popular of the hydroponic shoots. Pea tendrils are the thin, stringy, feathered green part, which the plant uses to attach itself to climbing frames. These days, peas for microgreen production have been bred, which produce tendrils on young pea seedlings, giving a highly attractive shoot with the flavor of mild freshly podded peas. As with all microgreen seed, peas for shoot production need to be untreated as any fungicide or other chemicals can be carried over to the harvestable portion of the seedling. Pea shoots are typically harvested at around four inches in height and can be stored in plastic bags under refrigeration. Growing at a high density in a single layer on microgreen pads or mats will give tall straight pea shoots with a white blanched stem and bright green leaves.

Hydroponic shoots are one of the most quick and versatile crops indoor growers can produce. They need only a small space, a kitchen tray, seedling mat and some dilute nutrient to grow one of the healthiest fresh crops possible. From salads, stir-fries, sandwich fillings and juices, edible shoots are worth giving a try.

Feature Article: May, 2009