Growing White Widow Cannabis [The Grower’s Guide]

Get the most potent yields!

The White Widow strain is one of the most popular in the world for both recreational and medicinal users. As a result, it isn’t a cheap purchase, as you can expect to pay over $300 an ounce in California, for example. In this guide, we outline how to grow White Widow with information on flowering time, expected yield, and a whole lot more.

Overview of the White Widow Strain

As you will see when you look at the profile of the White Widow strain on, it is an indica-dominant (60%) hybrid with a THC content ranging from 18-25%. It was first produced by Green House Seeds in the early 1990s and soon became the toast of the Amsterdam coffee-house scene.

White Widow is known for the potency of its head high, coupled with the fact it keeps you baked for several hours at a time. It is a cross of a South American sativa and a South Indian indica. You can identify this strain by looking at the buds which are covered in sticky resin, one of the main reasons why White Widow is so powerful.

Once you use this strain, expect a rapid cerebral high followed by a feeling of euphoria. It is a fantastic social strain because it gives you energy, ensures you remain aware of your surroundings, and never lets you succumb to couch-lock. It gets the name White Widow from the fact that it looks as if the strain has been dipped in sugar. White Widow offers a strong sweet and spicy scent coupled with an earthy pine taste.

It is normally used as a medicinal strain for patients with conditions such as ADD/ADHD and PTSD. However, you can also use it if you suffer from stress because it is the perfect wind-down smoke.

White Widow – Early Stages

white widow flowering time

When growing White Widow, please be aware that you can do it indoors or outdoors. If you are a home grower, you should start small and use five feminized White Widow seeds. The moist paper towel technique is probably the best way to germinate the seeds. Next, place them in small pots and use a high-quality soil mix to ensure the roots grow quickly. Good options include soil mixes containing natural ingredients such as bat guano. Place a thin layer of plastic between the soil and pot to make it easy to transplant when the plant gets bigger.

According to Green House Seeds, White Widow is best grown using the Screen of Green (SCROG) method. This is a low-stress training method which involves the use of a screen to make a canopy. Rather than tying the plant down, wait for it to grow through the screen. After the branches come through, tuck them back into the screen. By the flowering stage, you will have a garden capable of producing a lot of colas.

Most cannabis tips regarding White Widow suggest that it works best in a hydroponic setup. This involves using a material such as Rockwool as a growing medium instead of soil. However, White Widow also thrives just as well when soil is used instead. After a couple of weeks, your plants should enter the vegetative stage.

Typically, White Widow remains in this stage for up to eight weeks, during which time we recommend exposing it to a minimum of 18 hours of light a day. Once the plants outgrow their original containers, switch them to larger pots to ensure they develop a strong root system along with a thicker stem. Ideally, you will make sure the light focuses low on the plant but avoid burning the tips!

Once you have reached the eight-week mark, or feel that your plant is ready, switch to a 12-day cycle. It is at this stage that you can implement the SCROG method. It is imperative that you evenly distribute the light. Otherwise, you won’t achieve maximum yields.

Flowering Time for White Widow

If you believe your White Widow crop is ready for flowering, expose it to 12 hours of continuous darkness a day for a couple of weeks. Overall, White Widow’s flowering time lasts 7-9 weeks when grown indoors. If you are an outdoor grower, it will be ready for harvest by the end of October. Using the Pistil Method to check whether it is harvesting time, make sure that at least 70% of the pistils have turned amber before harvesting.

What Kind of Yield Can I Expect?

Most experts classify White Widow’s yield as moderate to low. If you grow indoors, you could yield up to 18 ounces per square meter. Outdoor growers normally benefit from a slightly larger yield at 21 ounces per square meter. Other growers suggest that you will receive up to 180 grams of weed (just over six ounces) per plant when you grow indoors.

Ideal Growing Conditions for White Widow

It is important for you to know that White Widow is one of the hardest marijuana strains to grow, especially outdoors. Generally speaking, most marijuana strains thrive in temperatures of 70-80 degrees Fahrenheit. However, White Widow is capable of absorbing more light at even higher temperatures. We’ve heard reports of growers exposing their plants to temperatures of up to 90 degrees.

Make sure the temperature stays above 70 degrees during the day and above 60 degrees at night. Your White Widow plants will be mildly shocked at 55 degrees and will die if repeatedly exposed to temperatures below 50 degrees. As for humidity, keep it at 70% during germination and drop down into the mid to upper-60’s during the vegetative stage. Once it reaches the flowering stage, reduce by up to 5% weekly until it is in the 30-40% range.

You can go as high as 95 degrees IF you include carbon dioxide enrichment of 1500 ppm and vent regularly to ensure humidity remains at a lower level. The main reason why White Widow does extremely well in high CO2 conditions is that it evolved in an era where natural carbon dioxide levels were several times higher than they are today. When you boost the CO2 level, you significantly increase the plant’s ability to manufacture the sugars it needs to grow.

Feeding White Widow

growing white widow

All growers know that Nitrogen (N), Phosphorus (P), and Potassium (K) are the mainstays of the garden. When purchasing plant food, you’ll probably notice three numbers on the front. These represent the N-P-K content of the food in percentage form. For example, a 20-15-15 formula is comprised of 20% N, 15% P, and 15% K.

Make sure your plant receives more Nitrogen in the vegetative stage but reduce it in flowering. At that stage, plants need more Phosphorus and Potassium to help boost their THC content. Other important nutrients include Sulfur, Magnesium, and Calcium, and you must also add trace amounts of Manganese, Zinc, Copper, Boron, Iron, and Molybdenum.

It is imperative that your growing medium has good drainage. If you normally water your plants once a week, for example, you can decrease it to every 3-5 days if your soil has good drainage. A good tip is to add perlite or lava rock to the medium as this helps with drainage. Finally, please make sure that you stop watering your White Widow plants around two weeks before harvesting. Otherwise, your precious strain will taste like plant food!

For the record, White Widow performs well at a slightly higher pH than other strains. While most strains do best at a pH of 6.0, you can bump it as high as 6.5. If you are using a hydroponics setup, lower the pH by 0.5 or so. A pH meter is a great investment. You can pick one up for a few bucks, and it helps you check if your plants’ soil is becoming too acidic or alkaline.

White Widow Pests

Pests are an issue with White Widow whether you grow it indoors or outdoors. Aphids, mites, fungi, caterpillars, and whiteflies are the worst offenders as they are capable of causing significant damage to your crop. If you bring in White Widow plants from outside, make sure you use pyrethrum on every leaf before storing them in your growing room.

White Widow is susceptible to bud rot or fungus when its flowers are half developed. Your plants are at greatest risk when grown in a room with a temperature between 60 and 80 degrees Fahrenheit and a high humidity level. This is one of the reasons why you should reduce humidity levels by the flowering stage.

There are a host of safe fungicides on the market that won’t expose your White Widow plants to nasty chemicals. Alternatively, you can try a homemade solution. We find that a combination of chili pepper powder and tobacco juice works wonders for handling mites. You can even mix soap and dish detergent to remove spiders. Typically, this solution breaks down into non-toxic elements within a week.

Final Thoughts on How to Grow White Widow Marijuana Strain

Hopefully, this guide to growing White Widow will prove useful whether you grow it indoors or outside. It is a powerful strain, and when you optimize its growing conditions, its final THC content of around 25% will provide you with an extremely potent, pleasant high.