Watermelon Ultra Feminized Seeds – TH Seeds | 24% THC & Spicy Kush Flavor

Watermelon Ultra feminized seeds by TH Seeds represent the ultimate mind-control experiment for your garden, blending a mouth-watering spicy watermelon flavor with a devastatingly relaxing 24% THC punch.

Before discovering this genetic masterpiece, your grow tent might feel like a revolving door of underwhelming hybrids. You spend months nurturing plants that promise exotic flavors but end up delivering generic, muted terpene profiles and airy buds that barely make a dent in your stash jar.

There is nothing more frustrating than wasting premium nutrients, electricity, and your valuable time on genetics that lack vigor. Trimming leafy, low-yielding plants is a chore, and when the final smoke lacks that heavy-hitting potency or unique flavor, the entire cultivation cycle feels like a missed opportunity.

Watermelon Ultra steps in to completely revolutionize your growing experience. By crossing a juicy Watermelon mother with the legendary Cannabis Cup winner MK-Ultra, TH Seeds has engineered a 60% Sativa powerhouse that grows with explosive vigor, produces rock-hard, resin-drenched colas, and fills your jars with an unforgettable eucalyptus and spicy watermelon aroma.

Before growing with Watermelon Ultra

Before you drop these premium seeds into the dirt, you need to prep your space for a vigorous beast. This strain has a serious stretch factor, so vertical space management is crucial. Get your pruning scissors ready and make sure your trellis nets are untangled, because you are going to need them. Mentally prepare yourself for a heavy yielder that demands a solid feeding schedule to support its massive flower production.

• Install a fresh carbon filter; the spicy fruit aromas start early.
• Prepare a well-aerated substrate to ensure explosive root growth.
• Plan your topping strategy to encourage lateral branching.
• Ensure your grow lights can penetrate a wide, bushy canopy.

During cultivation

Once she enters the vegetative stage, you will notice her aggressive growth rate. This is the perfect time to apply LST (Low Stress Training) and multi-topping. She loves to spread out, and by training her early, you create an even canopy that maximizes light absorption. The internodal spacing is ideal—not too tight, not too stretchy—allowing for great airflow.

When you flip the lights to 12/12, the magic really happens. The white resin starts shining like little diamonds surprisingly early in the flowering stage. You will catch whiffs of sweet watermelon mixed with a pungent, earthy kush backbone. Keep an eye on the humidity during weeks 6 to 8; those buds get incredibly dense, and you want to keep the environment dialed in to prevent any mold issues.

After: results and maintenance

When harvest day finally arrives, you will be thanking the cannabis gods for her excellent leaf-to-flower ratio. Trimming Watermelon Ultra is an absolute breeze, leaving you with dense, sparkling nuggets and a pile of sugar leaves that are begging to be turned into ice-o-lator hash.

After a proper cure, the effects are nothing short of hypnotic. It starts with a euphoric, appetite-enhancing cerebral buzz that slowly melts into a heavy, couch-locking body stone. Maintenance-wise, just keep your cured buds in airtight glass jars at around 62% humidity, and those spicy watermelon and eucalyptus terpenes will only get louder over time.

Short- and long-term advantages and benefits

• Because it features G13 heritage from MK-Ultra, you get explosive lateral branching, which means massive yields that fill your stash jars to the brim.
• Thanks to its excellent leaf-to-flower ratio, you can trim the buds in record time, which means less sticky frustration and more time enjoying your harvest.
• Because it produces thick, diamond-like resin early in flowering, you can create premium-grade hash and extracts, which means you maximize the value of every single plant.
• Thanks to its unique spicy watermelon and eucalyptus terpene profile, you experience a refreshing, gourmet flavor, which means your palate is treated to a dessert-like smoke every session.
• Because it delivers a potent 24% THC hybrid effect, you feel initial mental euphoria followed by deep physical relaxation, which means it is the perfect nightcap to melt away daily stress.
• Thanks to its vigorous response to topping, you can easily control its height indoors, which means you optimize your grow tent space without sacrificing production.

Technical specifications

• Breeder: TH Seeds
• Type: Feminized photoperiod
• Dominance: 60% Sativa / 40% Indica
• Genetics: WaterMelon × MK-Ultra
• Flowering time (Indoor): 8–9 weeks
• Outdoor harvest: Early to mid-October (Northern Hemisphere) / Early to mid-April (Southern Hemisphere)
• Yield Indoor: 450–600 g/m² (1.48–1.97 oz/ft²)
• Yield Outdoor: 600–800 g/plant (21.16–28.22 oz/plant)
• Height Indoor: 1.20–1.60 m (3.94–5.25 ft)
• Height Outdoor: 1.20–1.60 m (3.94–5.25 ft)
• Difficulty: Medium (requires canopy management)
• Structure and vigour: Tall, bushy, wide tree structure with a 2x–3x stretch in pre-flowering.
• Ideal climate: Temperate, Mediterranean; prefers low humidity in late flower.
• Training: Highly recommended for topping, multi-topping, and SCROG.
• Recommended pot: 11–20 L depending on vegetative time.
• Smell in grow: High (carbon filter strongly advised).
• THC: Approx. 22–24%
• CBD: Low
• Aromatic profile: Spicy watermelon, eucalyptus, tropical fruits, and earthy Kush.
• Effect: Euphoric and appetite-enhancing at first, transitioning into a heavy, relaxing body stone.

Stages and monitoring of Watermelon Ultra

Quick overview: Feminized photoperiod · TH Seeds · 8–9 weeks flowering · Ideal for SCROG indoors.

Safe start: Germinate at 22–25 °C and transplant once the taproot is 1 cm (0.39 in) long.

• Keep humidity around 70% for the first few days.
• Use a light, airy soil mix to prevent waterlogging.
• To accelerate germination safely, X-Seed Organic Vegan Seed Germinator by BAC boosts early vigor.

Directed growth: Maintain 18/6 light cycle and prepare for a 2x to 3x stretch.

• Apply topping or multi-topping early to widen the canopy.
• Keep temperatures between 22–26 °C for optimal metabolism.
• Feed with Top Veg Top Crop to build a robust, branching structure.

Efficient flowering: Switch to 12/12 and manage the canopy as buds stack rapidly.

• Lower humidity to 40–50% to prevent botrytis in dense colas.
• Add Monster Bloom Grotek during peak weeks for rock-hard density.
• Support heavy branches with stakes or a trellis net.

Harvest and refinement: Flush roots 10 days prior to enhance the spicy watermelon terpenes.

• Harvest when trichomes are mostly milky with 20% amber.
• Dry slowly at 18–22 °C and 50–60% RH.
• Cure for at least 3 weeks to unlock the eucalyptus notes.

Frequently Asked Questions

How much does Watermelon Ultra stretch during flowering?

This strain is known for a significant stretch, typically doubling or even tripling in size once you switch to a 12/12 light cycle. Topping and SCROG techniques are highly recommended to control its height indoors.

Is Watermelon Ultra good for making hash?

Absolutely. Thanks to its MK-Ultra lineage, it produces a massive amount of trichomes very early in the flowering stage. The resin is thick and highly aromatic, making it a top-tier choice for rosin, BHO, or ice-o-lator extractions.

What does the 710 Limited Special Pack include?

The exclusive 710 edition gives you 7 feminized Watermelon Ultra seeds plus 1 bonus French Macaron seed, all for the price of a standard 5-pack. It is a limited run, so grab it while supplies last!

What are the dominant flavors of this strain?

You can expect a very unique terpene profile dominated by sweet, juicy watermelon and spicy Kush notes, finished with a surprising and refreshing hint of eucalyptus on the exhale.

Personal Experience of Pevgrow’s CEO (Alan)

When TH Seeds dropped this mind-control experiment, I knew I had to get my hands on the 710 limited edition pack. Getting 7 Watermelon Ultra seeds plus a bonus French Macaron is an absolute steal. Before popping them, I made sure my carbon filter was fresh because this strain reeks of sweet, spicy fruit even in late veg. During the grow, I noticed she stretches quite a bit—easily doubling in size—so I went heavy on the multi-topping. She responded beautifully, turning into a wide bush of frosty colas. After the dry and cure, the results were insane. The buds are rock-solid, and the flavor is exactly like a spicy watermelon candy with a weirdly delicious eucalyptus kick on the exhale. It hits the head first, making you super chatty, and then drops an anvil of relaxation on your body. If you want top-tier hash, the trim from this girl is absolute gold.