Sweet basil 'Dark Opal' (Ocimum basilicum 'Dark Opal') Flower, Leaf, Care, Uses

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Sweet basil 'Dark Opal'

Ocimum basilicum 'Dark Opal'

Also known as: Saint-joseph's-wort 'Dark Opal', Common basil 'Dark Opal'

The sweet basil 'Dark Opal' isn't an easy variety to grow, but with its eggplant color and mild licorice flavor, they are well worth the extra care. This annual herb, cultivated by John Scarchuk and Joseph Lent from sweet basil in the 1950s, loves hot weather and makes a beautiful ornamental bush. Pop flower buds off to promote the best leaf growth.

9 to 11

Hardiness Zones

More Info

Plant Type

Herb

Bloom Time

Summer

Leaf Color

Green

Purple

Scientific Classification

Phylum

Vascular plants

Class

Dicotyledons

Order

Mints plantains olives and allies

Family

Mint

Genus

Ocimum

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Questions About Sweet basil 'Dark Opal'

Watering

What is the best way to water my Sweet basil 'Dark Opal'?

To water Sweet basil 'Dark Opal', you can use a garden hose with a spray nozzle, a watering can, or just about any other common watering tool. Generally, Sweet basil 'Dark Opal' is not too picky about how they receive their water, as they can live off of rainwater, tap water, or filtered water. Often, you should try not to water this plant from overhead, as doing so can damage the leaves and flowers and may lead to disease as well. At times, the best method for watering this plant is to set up a drip irrigation system. These systems work well for Sweet basil 'Dark Opal' as they apply water evenly and directly to the soil. For one Sweet basil 'Dark Opal' that grows in a container, you can use a similar watering approach while changing the tools you use. To water a container-grown Sweet basil 'Dark Opal', use a cup, watering can, or your tap to apply water directly to the soil.

What should I do if I water my Sweet basil 'Dark Opal' too much or too little?

The remedy for underwatering Sweet basil 'Dark Opal' is somewhat obvious. When you notice that your plant lacks moisture, simply begin watering it on a more regular basis. The issue of overwatering can be a much more dire situation, especially if you fail to notice it early. When your Sweet basil 'Dark Opal' is overwatered, it may contract diseases that lead to its decline and death. The best way to prevent this outcome is to choose a proper growing location, one that receives plenty of sunlight to help dry the soil and has good enough drainage to allow excess water to drain rather than pooling and causing waterlogged soils. If you overwater your Sweet basil 'Dark Opal' that lives in a pot, you may need to consider changing it to a new pot. Your previous container may not have contained soil with good drainage or may not have had sufficient drainage holes. As you repot your overwatered Sweet basil 'Dark Opal', make sure to add loose soils and to use a pot that drains efficiently.

How often should I water my Sweet basil 'Dark Opal'?

Sweet basil 'Dark Opal' needs water regularly throughout the growing season. Beginning in spring, you should plan to water this plant about once per week. As the season presses on and grows warmer, you may need to increase your watering rate to about two to three times per week. Exceeding at this rate can be detrimental to your Sweet basil 'Dark Opal'. With that said, you should also ensure that the soil in which your Sweet basil 'Dark Opal' grows remains relatively moist but not wet, regardless of how often you must water to make that the case. Watering Sweet basil 'Dark Opal' that lives in a pot is a bit different. Generally, you'll need to increase your watering frequency, as the soil in a pot can heat up and dry out a bit faster than ground soil. As such, you should plan to water a container-grown Sweet basil 'Dark Opal' a few times per week in most cases, versus just once per week for an in-ground plant.

How much water does my Sweet basil 'Dark Opal' need?

There are a few different ways you can go about determining how much water to give to your Sweet basil 'Dark Opal'. Some gardeners choose to pick their water volume based on feeling the soil for moisture. That method suggests that you should water until you feel that the first six inches of soil have become moist. Alternatively, you can use a set measurement to determine how much to water your Sweet basil 'Dark Opal'. Typically, you should give your Sweet basil 'Dark Opal' about two gallons of water per week, depending on how hot it is and how quickly the soil becomes dry. However, following strict guidelines like that can lead to overwatering if your plant requires less than two gallons per week for whatever reason. When growing Sweet basil 'Dark Opal' in a container, you will need to use a different method to determine how much water to supply. Typically, you should give enough water to moisten all of the layers of soil that have become dry. To test if that is the case, you can simply stick your finger in the soil to feel for moisture. You can also water the soil until you notice a slight trickle of excess water exiting the drainage holes of your pot.

How can I tell if i'm watering my Sweet basil 'Dark Opal' enough?

It can be somewhat difficult to avoid overwatering your Sweet basil 'Dark Opal'. On the one hand, these plants have relatively deep roots that require you to moisten the soil weekly. On the other hand, Sweet basil 'Dark Opal' are plants that are incredibly susceptible to root rot. Along with root rot, your Sweet basil 'Dark Opal' may also experience browning as a result of overwatering. Underwatering is far less likely for your Sweet basil 'Dark Opal' as these plants can survive for a while in the absence of supplemental watering. However, if you go too long without giving this plant water, it will likely begin to wilt. You may also notice dry leaves.

How should I water my Sweet basil 'Dark Opal' through the seasons?

You can expect your Sweet basil 'Dark Opal'’s water needs to increase as the season moves on. During spring, you should water about once per week. Then, as the summer heat arrives, you will likely need to give a bit more water to your Sweet basil 'Dark Opal', at times increasing to about three times per week. This is especially true of Sweet basil 'Dark Opal' that grow in containers, as the soil in a container is far more likely to dry out faster than ground soil when the weather is warm. In autumn, while your Sweet basil 'Dark Opal' is still in bloom, it may need a bit less water as the temperature has likely declined, and the sun is no longer as strong as it was in summer.

How should I water my Sweet basil 'Dark Opal' at different growth stages?

Sweet basil 'Dark Opal' will move through several different growth stages throughout the year, some of which may require more water than others. For example, you will probably start your Sweet basil 'Dark Opal' as a seed. While the seed germinates, you should plant to give more water than your Sweet basil 'Dark Opal' will need later in life, watering often enough to maintain consistent soil moisture. After a few weeks, your Sweet basil 'Dark Opal' will grow above the soil and may need slightly less water than at the seedling phase. Then, once this plant is mature, you can begin to use the regular watering frequency of about once per week. As flower development takes place, you may need to give slightly more water to aid the process.

What's the difference between watering Sweet basil 'Dark Opal' indoors and outdoors?

There are several reasons why most Sweet basil 'Dark Opal' grow outdoors rather than indoors. The first is that these plants typically grow to tall. The second reason is that Sweet basil 'Dark Opal' needs more daily sunlight than most indoor growing locations can provide. If you are able to provide a suitable indoor growing location, you may find that you need to give your Sweet basil 'Dark Opal' water a bit more often than you would in an outdoor growing location. Part of the reason for this is that indoor growing locations tend to be a lot drier than outdoor ones due to HVAC units. The other reason for this is that soil in containers can dry out relatively quickly as well compared to soil in the ground.

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Add to My Garden

Sweet basil 'Dark Opal'

Ocimum basilicum 'Dark Opal'

Also known as: Saint-joseph's-wort 'Dark Opal', Common basil 'Dark Opal'

9 to 11

Hardiness Zones