Watermelon Autoflower: A Summertime Legend
Watermelon Auto delivers gorgeous looks and savory flavors with calming and uplifting effects. Equipped with genes from Tropicana Cookies and Lemon OG, this resilient strain is perfect for novices and advanced growers.
Watermelon Auto is a heavy hitter when it comes to its potency. Racking up a THC content of 20%, newbies better be warned to tread carefully. For experienced users, its above average CBD content makes it easy to handle.
With well-thought-out parents and careful genetic stabilization, Watermelon Auto measures 75% Indica dominance paired to 20% Sativa and 5% Ruderalis. The significant Indica dominance shows up in its growth and calming effects.
This strain has the looks that make your mouth water. From the branch bases to their ends, spherical shaped colas with plump nuggets command your attention. Their mint green colour is almost obscured by a heavy blanket of shimmering trichomes and a rich, sugary resin cover extending to the leaves.
Legend
Calming & Happy | |
THC: 20% | CBD: 0% | |
Tropicana Cookies x Lemon OG | |
75% Indica – 20% Sativa – 5% Ruderalis | |
70-110 cm | |
500 g/m² | |
8-9 weeks | |
90-120 cm | |
300 g/plant | |
6-7 weeks |
Effects and Flavor Profile
It says it right in the name, Watermelon Automatic is bursting with flavor and aroma. This delightful girl takes on a rich terpene profile that is dominated by limonene, myrcene, and caryophyllene.
75% Indica – 20% Sativa – 5% Ruderalis | ||
Calming, Happy, Uplifting | ||
Myrcene, Limonene, Linalool | ||
Dank, Fruity, Pungent |
Aroma
Once the buds start to form, your grow room fills with a ripe watermelon essence. It gets richer during curing and adds more undertones as you break and smoke your flower. On the inhale, deeper notes of ripe berries rush into your nostrils and deliver a burst of fruitiness that continues on the exhale.
Taste
With the first whiff going in, you get a fruity hint exploding over your tongue. It then quickly evolves into a complex candy sweetness. And before long, you will be savoring watermelon auto’s signature clean and refreshing aftertaste.
Effects
Thanks to its potent THC content, watermelon auto’s effects are well pronounced and can be felt almost immediately. With an indica dominant profile, you will find them more physical but soothing for the body, mind and soul. The best part is the calm and collected aftermath.
Euphoric
The very first effect to arrive is a gentle elevation in mood. This way, watermelon auto fits social gatherings while making casual conversations more enchanting. The uplifted state is also perfect for Netflix and chill sessions.





May 28, 2025
Watermelon Autoflower flowered very quickly and was able to get a solid yield growing outside.
Todd M
Growing Watermelon Autoflower
These cannabis seeds fit the bills of both novice and experienced growers. They show proper resilience against mold and disease attacks. Well, there is more reason to select these seeds for your next grow.
Height
Watermelon auto plants have a fir tree-like appearance with a large central cola that is surrounded by numerous satellite buds. Their compact size can fit into most indoor tents or closets. It also makes them stealthy even to nosy neighbors.
Indoors, this strain reaches just 70-110 cm. Growing on their own outdoors, they stretch to a manageable 90-120 cm.
Feminized Plants with a Speedy Cycle
Being 100% feminized, these watermelon auto cannabis seeds guarantee you female plants. This saves you the time and energy used to identify and remove any potential males at an early stage.
The flowers come out quickly, thanks to this girl’s autoflowering seed genetics. In just 6-7 weeks, you can expect them to be fully mature indoors. Outdoors, you can prepare for harvest 8-9 weeks after they sprout.
Versatility and Yield Potential
Watermelon auto seeds are incredibly versatile. Not even the short summers at the poles can stop you from getting a respectable 300g per plant outdoors. Indoor growers should expect as much as 500g per square meter in controlled environments.
CLIMATE INTENDED
Very Hot | Hot | Moderate | Cold | Very Cold |
Managing the Compact Structure for Maximum Yields
Watermelon auto plants’ dense and compact nature may be good for tight spaces and stealth. They may, however, require some unique skills to maximize yields.
Optimizing Light Distribution
Maximum light penetration is important as it helps the plants photosynthesize. The compact nature and stature may block light from reaching lower leaves. Here are actionable tips to help you optimize light penetration and distribution.
- Choose the right light for indoor growing setups. Light-emitting diodes (LED) and High-Pressure Sodium (HPS) lights are the best recommended. LEDs are generally the better option as they emit less heat.
- Frequently check and adjust the distance between your plants and the lights. As the plants grow towards the light, they may get scorched or stressed from heat. It is advised to keep this distance about 50 cm to maximize their coverage.
- Use reflective material to line your grow room. The reflective surfaces help to bounce the light back in all directions to enhance distribution, especially to lower leaves and side branches.
- Rotate your plants for fixed light sources. Indoor growers, depending on window lights, can rotate their pots so the plant is evenly exposed to direct light. This helps with the uniform development of your plant’s canopy.
Pruning and Training
The dense foliage can be detrimental to the plants if left unattended. The leaves form a humidity trap apart from blocking light and optimal airflow. This is a common recipe for pests, diseases and mold attacks.
It is important to prune any fan leaves that may be superimposing potential bud sites. It also helps the plant to focus its nutrients and other resources on meaningful development. Combining defoliation with low-stress training (LST) has shown significant improvement in the yields.

Pro Grow Tip : Watermelon needs a sub tropical climate with lots of sunlight and longer daylight hours. Well draining soil is essential.
Growing Conditions
The growing conditions of your watermelon auto plants have a direct relation with your yield. Carefully controlling the environment helps the compact watermelon auto plants thrive with ease.
A temperature of 70–80°F (21–27°C) is important for steady and healthy growth. Fluctuations in temperature often shock the plants. Avoid drops or rises of more than 10°F (5°C).
Origin And History
When creating this strain, Royal Queen Seeds went through a meticulous breeding process. Initially, the breeders wanted a rich terpene profile that would ignite your taste buds. And after generations of cross-breeding and stabilization, watermelon auto was created.
To make this strain happen, RQS selected Tropicana Cookies and Lemon OG. The two parents passed down their distinct terpenes over generations to achieve Watermelon Auto’s unbeatable character.
Growtime –
Perfect summertime strain for sure. Seeds germinated quickly and we were able to get some great plants from our first batch.