Basil Varieties

Basil can be sweet, savory or peppery and it has an amazing smell. The herb has been used in almost every place in the world in one way or another, the herb was also thought to spawn scorpions. Basil belongs to the mint family (Lamiceae), along with oregano, rosemary, thyme and serveral other herbs.

While most of us are familiar with the traditional, large-leaved sweet or Genovese basil used in a huge range of dishes, often associated with tomato, chillies, peppers, in hot salsas and blitzed into pesto, basil varieties are far more diverse than just these cultivars.

Basil can be found in many shapes and forms, from the glossy green leaves that make it highly attractive to the purple, frilled, ruffled and spotted cultivars. They not only have the distinctive basil flavor but also brighten up hydroponic system with a variety of intense color.

You can find basil in different sizes and forms, some of them being bred for container production, while while flavor varieties in basil makes it perfect for culinary use. Well-suited basil types for hydroponic production like Dark Opal, Purple Ruffles, Purple Delight, Basil Bicolor and Red Cubin are prone to have intensive coloration under high light levels.

Of the sweet green types, Elindra and Genovese Compact are the ones suited for indoor growing and are specifically bred for container and greenhouse production. Those cultivars are perfect for gardeners short on free space. Two Genovese sweet basil types that are taller being Nufar and Aroma 2 have a resistance to fusarium root rot disease.

For basil that’s being bred for pesto production, specific varieties like Napoletano, Lettuce Leaf Basil and Italian Large Leaf cultivars produce sweeter foliage than the Genovese types with leaves up to 4-inches long.

One of the more popular exotic basil varieties that are well-suited to hydrponic production inclue:

Cinnamon Basil Spicy Basil Sweet Thai Basil with its distinctive anise-clove flavor Holy Basil with a spicy flavor Globe/Greek Basil with small leaves suited to restricted spaces Citrus and Lime Basil that have a strong citrus slightly mixed with basil flavor sort of combination.

If you are considering basil for large-scale hydroponic production, cultivars with inbred disease resistance to common diseases like downy mildew is your choise.

Basil Propagation

Basil is usually propagated from seeds, which are available in raw and pelleted form. However you can also get cuttings that will form roots within the next week or more.

The basil seeds germinate readily under warm conditions with 75˚F / 23°C being the perfect temperature for growing most of the basil types and will usually take between five to seven days. You can use rockwool propagation blocks if you are going to do commercial production or if the provided medium is sterilized. You can use perlite/vermiculite, peat moss, foam substrates, coconut fiber and sand culture.

You will have to make sure the growing media during the early post germination stages is not overly wet due to Basil seedlings being extremely prone to pythium and other damping-off pathogens.

Once your seedling leaves have expanded, you will have to apply a dilute nutrient solution at an electrical conductivity of 0.5 mScm-1 with a pH of around 5.8 to 6.2. Once you have transplanted the seedlings into a hydroponic system the EC can be steadily increased and supply it with full, high-intensity light levels.

Air movement and ventilation under the plants to prevent some of the fungal infections such as grey mold are formed under tall and dense stems of many basil varieties. The main reason being high humidty in the area they are being grown which makes it perfect for fungi to form and ruin everything.

Like cilantro which we are going to talk about in another article, basil can be prone to bolting at a fairly young age if the plants are stressed enough. Overly dry environments, excessive light or temperatures, overcrowding and root restriction are one of the many problems you may encounter if bolting occurs.

If you happen to have flower buds they can be easily removed from the growing points as they develop. But once they can be seen it’s usually more economical friendly to just replace with young transplants unless you want to use the blooms for culinary use.

What are the essential nutrients for Basil?

Usually what you will find in most hydroponic systems used for basil is a general-purpose lettuce/herb or vegetative nutrient formulation. While this is suitable for young plants, as the basil seedlings get more mature they will require a different nutrient uptake ratio.

The amounts of pottasium (K) and calcium (Ca) are relatively high in the edible portion of the basil plant. For this reason you will have to keep the ratio of K:Ca in the nutrient solution close to 1:1.

While nitrogen (N) is essential for leave yields and needs to be maintained at all times, potassium and calcium are directly related to the oil levels and flavor in the foliage. You should keep magnesium (Mg) at levels 50 ppm because there is a direct relationship between the Mg content, yield and composition of the essential oils that make the basil flavor and aroma so unique.

When to harvest your basil crop?

It doesn’t matter wether you grow basil in your indoor garden or commercially in a greenhouse, both can be harvested in a similar fashion. Basil being a cut and re-grow corp with only one-third to two-thirds of the upper foliage taken as stems, leaving it to regenerate for a future two to three cuts before replacing the plants.

You can as an alternative to pluck the lower mature leaves individually and remove the growing tips as soon as the plants reach a reasonable height to promote the development of new stems and keep the plants compact.

One of the issues with freshly harvested basil is their limited shelf life which is caused by the volatile compounds that contribute to the unique flavor of basil to deteriorate rapidly. Once the basil is cut, there are specific requirements so it’s kept fresh as long as possible, one of them being that basil should not be stored in a refrigerator below 50˚F / 10°C. As the cold will damage the leaves and make them go black.

Once harvested, basil has to be lightly wrapped in plastic and stored at temperatures at around 52˚F / 11°C to 57˚F / 13°C. You can put the cut stems in a glass of water at room temperature to maintain the shelf life for several days.

Photo Credit

Plant PVC Pipe (Aeroflo)