8 Tips for Cultivating Harlequin Marijuana [Growers Guide]

Although THC-laden strains are popular for medical use, CBD has become a highly sought-after cannabinoid. According to the ‘entourage effect,’ cannabinoids work better together than in isolation. As a result, any strain that combines CBD and THC provides a superior medical benefit in theory.

This is where Harlequin comes in. It is a sativa-dominant (75%) hybrid containing 7-15% THC and 10-15% CBD. In other words, this strain offers you the best of both worlds. You still attain a high but it is manageable, and you also get the healing effects of two powerful cannabinoids.
Harlequin is a cross of a Swiss landrace, Colombian Gold, and a Thai Sativa. It has been heralded as the ideal smoke for when you need a mental pick-me-up. Once you use this strain, you will feel an improvement in your mood, and while there is certainly a ‘high,’it is one that is easily controlled. As a result, you can use Harlequin at any point during the day since it enables you to retain your functionality.

You may even experience an energy boost, so use this strain if you need to get some work done. Remember, the CBD will calm the high caused by the THC, so you can expect to feel clear-headed. It is a sweet-smelling plant, and it has an herbal and spicy taste. Its high CBD levels mean it is an excellent medicinal strain, used to treat conditions including depression, muscle spasms, and joint pains. In this growing guide, we provide you with eight tips and tricks to help you grow Harlequin effectively.

1 – Should You Grow Harlequin Indoors or Outdoors?

Although you can grow Harlequin indoors or outside, you will enhance the CBD content by growing inside in a controlled environment. As a general rule, CBD-rich plants must be harvested fairly early because cannabidiol degrades at a much faster rate than THC.

harlequin cannabis strain

If you grow it outdoors, make sure you pay attention to humidity levels and be prepared to harvest much earlier than with any THC-heavy strain. You could receive a yield of up to 21 ounces per plant. When growing indoors, flowering time is approximately 8 weeks, and you could enjoy a bumper yield of up to 25 ounces per square meter.

2 – Keep Humidity Levels in Check

Although Harlequin can handle higher humidity levels, it is best if you err on the lower side; especially if the temperature in your grow room is high. This strain likes higher temperatures, and the ideal range is 72-85 degrees Fahrenheit during the day, and 15-20 degrees lower at night, or when the lights are off indoors.

Humidity levels should be at their highest when your plants are still seedlings. Keep the relative humidity (RH) levels at around 65-80% at this stage. Once your plants are in the vegetative stage, drop the RH to 55-65%. At this point, your Harlequin plants will have strong root systems and absorb more water from the soil.

Once you switch to a 12-12 light cycle to force your plants into flowering, cut the RH to 40-50%. By the late flowering stage, aim for 30-40%, with daytime temperatures at approximately 75 degrees. If you are growing Harlequin outdoors, keep the humidity level below 50% as often as possible.

3 – Training Techniques

Harlequin is a big yielder, and you can get even more weed from the plant through proper training techniques. Above all else, training your plants will ensure good airflow in the canopy. Benefits include improved yields as all of the plant is exposed to light and airflow. If you don’t train or prune your Harlequin plants, they could develop bud rot.

Low-Stress Training (LST) involves bending or manipulating the branches to boost yield. LST itself means bending the plant as it grows and tying down any branches that become too long. By pulling the tops of the plants downward, your increase production of the hormone, auxin. SCROG is a variation of LST where you tuck branches down once they grow through a screen.

High-Stress Training (HST) methods are faster but also spell more danger for your plants. Topping is one of the easiest options and includes removing the tops of your plants with fingernails. When you do this correctly, the top buds become two new branches. As a bonus, the ‘shock’ you send to the rest of the plant results in lower branch growth.

4 – Feeding Your Harlequin

feeding your harlequin


A common mistake made by novice growers is to provide excess nutrients to seedlings. In reality, it is best if you begin with light feeding in the first week or two, especially if using soil as your growing medium. The nutrients from the soil should offer plenty of sustenance in the early stages.

If you are growing hydroponically, you have a greater level of control over nutrient intake. Rather than using store-bought chemical fertilizers, consider creating an organic compost tea to use with soil.

When your Harlequin plants are still seedlings, use clean, distilled water with a pH of 6.5-7.0 with no added nutrients for the first couple of weeks. The main nutrients required during the vegetative stage are Nitrogen, Phosphorus, and Potassium (NPK).

Here is what each nutrient can do for your plant:

  • Nitrogen: Boosts photosynthesis and is extremely important during the vegetative stage. Reduce nitrogen intake during flowering.
  • Phosphorus: Helps your plant grow strong roots; you should add more during flowering.
  • Potassium: Strengthens the metabolism of your plant, aids photosynthesis, and increases the production of vital proteins.

During flowering, it may also be a good idea to use a CalMag supplement – calcium and magnesium – as these nutrients improve the growth of your plants. Make sure you stop adding fertilizers 2-3 weeks before harvest.

5 – What About Lighting?

This is an issue faced by indoor growers. Your plants don’t need as much light as you think during the seedling stage. Fluorescent light tubes are often enough to help your young plants grow. Powerful sources such as HID lights could damage your crop if you don’t leave them far enough away from the seedlings. Begin with your seedlings 80 cm away from the HIDs, and reduce the distance each day, depending on the overall wattage.

As for the light schedule, 18 hours of light is normally enough, although some growers expose their seedlings to constant light. In the vegetative stage, make sure your Harlequin plants get at least 18 hours of light each day. Once you are ready to force your plants into flowering, decrease the light and change the light schedule so that there are 12 hours of continuous darkness each day.

When your plants are flowering, HID light, which falls in the yellow or red color band, will provide you with excellent results. An increasing number of grower’s favor LED lighting because it provides plants with a fuller spectrum of light and is more efficient than other types of light.

6 – A Note on Watering Your Harlequin Plants

A lot of growers make the mistake of not thinking clearly about the water they use on their plants. After all, if we can drink it, it must be okay for plants. In reality, it depends on where you live. In certain locations, the water contains an excessively high level of dissolved minerals that can build up in a plant’s root zone.

As a result, nutrient intake is affected. Alternatively, the water could contain pathogens that don’t impact humans but are devastating to plants because they cause root disease. In areas where water has high levels of chlorine, soil microbes could be affected. We recommend investing in a reverse osmosis (RO) system if the water in your area is far from being pure.

Another common issue is overwatering. When conditions are too wet, your plants could develop fungal root diseases. As a rule of thumb, dig your knuckle into the soil or growing medium. If it feels dry a couple of inches down, you can water the plant. Otherwise, wait until the soil is dry enough.

7 – What Happens During the Flowering Stage?

what happens during the flowering stage?


This is unquestionably the most exciting time because you know it is a matter of weeks before your weed is ready for harvest. With Harlequin, the flowering time is around 8 weeks. This is relatively short; there are sativa strains that take up to 16 weeks to flower! During the first week of flowering, you may notice a slight slowdown in growth. This will be followed by the appearance of small flowers at the nodes of the plants.

By the third week of flowering, your Harlequin plants will be almost finished growing, and it will have grown by between 25% and 50% in the last three weeks. Vegetative growth is practically finished by week four, and from this point onward, your plants will focus on producing the potent buds you yearn for.

After the midpoint, the flowers of the plant will experience an acceleration in growth. The buds start swelling with around three weeks left, and there will be a noticeable odor emanating from the weed. In the last two weeks, most of the plants’ calyxes will look ready to burst and produce resin. In the final week, the pistils start to change color, and a thick coat of trichomes will cover the plant.

8 – When Do I Harvest?

The flowering time of Harlequin is set at eight weeks, but this doesn’t mean you should wait for 56 days to elapse before harvesting. Check your plants regularly to see if the white pistils are beginning to change color. When harvest time approaches, the pistils switch to a red or deep orange color. Although you can harvest any time after 50% of the pistils change color, it is best to wait until 70-80% make the change. Leave it any later, and the buds you pick will offer a sedative-type high.

Harlequin, in particular, is known for being covered in a thick layer of trichomes when it is ready to harvest. Using the trichome method, wait until they are milky-white before plucking the buds. In some cases, the trichomes may have a mushroom-head at the optimal point of harvest. You will need to purchase a magnifying glass to identify the trichomes.

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