Article 6-1 Strawberry

One of the highlights of early summer is the sweet juicy taste of a fresh picked strawberry. Hydroponic strawberries are making a big impression! Grown without soil in a nutrient solution, hydroponic strawberries are the taste of the future.

Canada consumes far more strawberries than its annual production of approximately 30 million tonnes. The bulk of imports come from California and Florida which provide Canadians with fresh berries year round.

Strawberry growers worldwide fumigate the soil with methyl bromide before planting to control soil-borne insect pests, diseases and weeds. The fumigation is essential to meet the demands for top quality fruit and high yields. However, methyl bromide has proven detrimental to our ozone and in 2005 faces a worldwide ban. It is estimated that banning methyl bromide will cut in half the annual production of field-grown strawberries in California and Florida. For the consumer this will mean an increase in the already astronomical prices for fresh berries out-of-season. Growing strawberries hydroponically eliminates the need for methyl bromide. Many commercial growers have all ready switched to this method of cultivation.

Hydroponics is rapidly becoming recognized as the most productive and efficient form of food production. Whether produce is grown indoors under artificial light or outdoors in sunlight hydroponic cultivation offers strawberry growers many advantages.

One of the major benefits of growing strawberries hydroponically, aside from the magnificent taste, is that they can be grown at an elevated height. This has proven to be a great benefit to commercial growers as the picking rate is much faster and less fatiguing and cultivation of plants is easier.

Yields per plant are higher and losses are lower in hydroponics than in soil. Crops can be grown on poor land and weeds in the crop are virtually eliminated. Gardens can be vertically tiered to maximize the use of space. The sky’s the limit on how high you want to stack your gardens.

Strawberries are members of the Rose family (Rosaceae, genus Fragaria) which also includes other fragrant and flavourful species such as apples, pears, plums and cherries. Originally the succulent berries were called strew-berries for the way the runners and berries grew strewn across the ground. However, as so often happens with the English language, the name gradually evolved to strawberries.

Strawberries are not really berries or fruit in the “botanical” sense (i.e., the end result of a fertilized plant ovum). A strawberry is actually an “aggregate fruit” — the “real” fruit are the objects we think of as the “strawberry seed” (properly called “achenes”) which are fruits in the same way that a raw sunflower seed with it’s tough shell is a fruit. The “berry” is actually an “enlarged receptacle” and is not reproductive material. As a result, strawberries must be picked at full ripeness, as they cannot ripen once picked.

Rich in vitamin C, iron, potassium and fiber strawberries have also been credited as having cancer fighting compounds. For hundreds of years homeopathic practitioners have incorporated strawberry plants and fruit in the treatment of anemia, diabetes, rheumatic gout, and kidney and liver complaints. Fresh strawberry removes tarter and teeth stains, soothes sunburn and lightens freckles. Strawberry liqueurs, preserves and jellies are widely used worldwide. The average American consumes more than 1.4 kg. (3 lb.) of strawberries per year.

Growing strawberries hydroponically at home can produce enough berries to feed a family of four for a full year. Production doesn’t need to stop seasonally as a hydroponic system can be set up outdoors or indoors with artificial light.

A hydroponic system can be tailored to suit almost any growing application; strawberries are well suited for hydroponic cultivation. Perfect water and nutrient levels can be easily maintained to produce plump, juicy, unblemished fruit.

There are different categories of strawberries. The ones most commonly found in our hemisphere are the long-day-type. They flower in response to the long daylight hours of June, fruit in July then flower again, usually yielding little or no fruit from the second flowering.

Temperature has a major influence on strawberry physiology and can override day length as the control mechanism for flowering. If temperatures drop too low, vegetative growth is inhibited causing poor flower and fruit formation. Conversely if temperatures are too high strawberry plants will wilt and stop producing flowers and fruit.

Strawberries grown from seed will usually take two to three years to mature, not the ideal situation for hydroponic growers. Early in the season, after risk of frost is over, purchase cold-stored runners from your local nursery. Always use runners that are certified virus tested. Cold stored runners are off-shoots of a mature strawberry plant (also known as a mother plant) that have been snipped off and rooted, forming a clone of the original strawberry plant. They are kept in cold storage through the winter. Ideally the runners you choose will be in flower or have buds visible.

Determine which hydroponic gardening method will be suitable for your location and number of plants. Ebb and flow or flood and drain works well for a large number of plants, however, it is totally immobile once set up. Smaller, multi-tiered deep water culture, NFT (Nutrient Film Technique) or drip irrigation gardens seem to be the preferred choice for both hobby and commercial growers.

Carefully remove the runners or new strawberry plant from its container. Remove as much of the earth as you can by gently shaking and massaging the roots. Submerge the entire root system in a bucket of cold water for about 10 minutes then rinse roots under cold running water to remove any remaining dirt. Be very careful to inflict as little damage as possible to the roots and tiny root hairs as too much breakage will seriously stress plants and impair growth. Dry or brittle leaves and roots should be removed at this time.

It is important to keep the roots moist while planting. Exposure to the sun or wind will quickly dry out the tender rootlets. This drying will cause failures in the establishment of the planting. A convenient way to keep the roots moist is to wrap them in wet burlap and then carry them in a pail or basket.

Line the bottom of a hydroponic mesh pot with a sterile growing media. Leca, expanded clay pellets or heydite, or crushed shale rock work very well for strawberries. There are many other media available, discuss which one works best for the type of hydroponic garden you’ll be using with your hydroponic merchant.

Presoak all media in pH balanced water for at least a half hour prior to using. Dry media will act like a sponge and suck all moisture from plants roots.

Carefully place one strawberry plant in the pot with roots splayed over the media. Add enough of the growing medium to fill the pot making sure the crown of the strawberry is well above the surface. The crown requires light and fresh air as this is where new leaves and flowers grow. If submerged, the crown will rot causing the entire plant to die.

Insert the pot into your hydroponic garden and follow the instructions. Make sure plants receive a good water-to-air ratio and that roots are never left standing in still water or solution. A feeding regime with a standard two part bloom nutrient formula should provide all the nourishment that your strawberry plants will require to grow robust and flavorful berries. pH should be maintained between 5.8 and 6.2 to ensure maximum nutrient uptake.

There are several different types of strawberries suitable to various climates and zones. The long-day-type typically grown in northern regions are light and climate sensitive. Flower and fruit production is triggered by the long hours of spring and early summer light received by the plant. Once introduced to a warm climate, plants will continuously produce an abundance of flowers. Temperature also affects a fruit’s flavour and sugar content.

Conditions can easily be simulated indoors, out-of-season. Once plants have finished fruiting and produced runners, clip the runners from the mother plant and root using conventional rooting methods. Treat mother plants as annuals as they will not winter well in a hydroponic garden.

Once cuttings or runners have established a good root system, they must endure a chilling process. This may be done by placing rooted cuttings in a garage or cold cellar where temperatures remain between zero and 5°C. Chilling may last anywhere from 10 days to five months depending on when your next crop is desired.

Introducing the chilled cuttings to a growing environment at staggered times will yield a delicious supply of fresh berries year round.