Stevia – How Sweet It Is!
Stevia rebaudiana is an annual herb whose leaves can be used fresh or dried for sweetening tea, coffee, juices and on cereals as a sugar substitute. It is 250-300 times the sweetness of sugar. 1 tablespoon of stevia equals 1 cup (250 ml.) of sugar! A little goes a long, long way. The sweetness of the leaves can vary though depending on type of soil, growing zone climate and time of harvest.
Stevia is native to Brazil and Paraguay, China and Japan. Japan, in fact, has banned the use of all artificial sweeteners except stevia and has done so since the 1970s. It consumes more stevia than any other country in the world.
The active compounds in stevia are called steviol glycosides. These gylcosides cannot be metabolized by our bodies so contain zero calories. Stevia strengthens the immune system, promotes heart health, regulates blood pressure and helps to lower cholesterol.
I have never baked with stevia but have heard it can be tricky. It is not a true substitute for sugar in some recipes such as bread. Before baking with stevia, check it out on a reputable baking site on the net.
Stevia likes a full sun location inside or outside. (6-8 hours per day). It will not tolerate temps below 7 degrees C. and prefers a well draining, loamy soil mix with a pH of 6.2 to 7.2. If you can add compost to the soil mix all the better.
Stevia can be grown in a flower bed or in a container. Containers are handy as they can be moved inside for the winter. It is most important to transplant your stevia plants outside after all danger of frost is past. It is best to give it lots of room; 45 cm. between each plant in the ground. Mulch around the roots with a layer of compost to keep the feeder roots from drying out. At maturity, a stevia plant will be 76 cm. tall by 60 cm. wide.
Keep your stevia plants moist but not soggy. Water in the morning at ground level, not on the leaves.
Prune your stevia plant when it is approximately 20-25 cm. tall. Pruning encourages more branching resulting in the plant producing more leaves. Trim it back again in early summer.
Fertilize with a half strength application of water soluble 20-20-20 regularly; about once every two weeks.
Stevia is termed an annual herb but can be overwintered indoors and put outside again in spring. Prune the plants back to 6 inches tall in late fall and move inside to a sunny spot. New growth may not appear until spring when the days begin to get longer.
You can harvest stevia at any time – the new leaves are the sweetest. Harvesting in the fall is best as the leaves become even sweeter in cool temperatures. Early in the morning is best as the highest leaf sugar content occurs in the a.m. Do not let stevia go to the flowering stage. Even if only three to four flowers open, the entire taste of the leaves can change and lose some or all their sweetness.
You can also dry the stems (without the flowers) in a food dehydrator or hang them upside down to thoroughly dry. Once dry, grind them by hand or use a food processor to grind them into powder form. Store in an airtight container.
Pest and Diseases
Stevia is not prone to being bothered by many pests or diseases. Aphids and slugs tend to be the worst pests. Aphids can be trimmed off and garbaged and slugs can be deterred with diatomaceous earth or copper tape along the rim of the container. Watering from above and overwatering may cause Alternaria Leaf Spot and Botrytis.
Alternaria Leaf Spot
...appears as reddish round small spots with white or grey centers. These spots also can appear on the stems. Botrytis is a fungal disease that leads to a grey mold forming on all plant parts. Botrytis loves cool, wet weather conditions.
For a refreshing summer drink put a dozen stevia leaves into a pitcher, add boiling water to fill the pitcher, cover and chill in the fridge overnight. The next morning add freshly squeezed lemon juice to the mix; some ice in a glass and relax in the sun!