How to Grow Rock Start
Rock Start is a 70% indica-dominant feminized strain that crosses Sensi Star with Rockbud, a pairing strong enough to take a Cannabis Cup in 2012. It pairs an earthy, sweet flavor with a creative, giggly and relaxing effect, and carries a moderate THC level of 15 to 22%, which keeps it in the medium range. This guide walks through the whole grow, from germinating the seeds to the final cure.
It stays compact at around 3.94 ft yet turns in a high yield, with a genuinely huge outdoor return. Its award-winning genetics and forgiving nature make it a productive, beginner-friendly plant.
Recommended Strains
Rock Start
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THC | 15% - 22% (Medium) |
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Type | Feminized |
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Yield | High |
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Phenotype | 70% Indica / 30% Sativa |
Rock Fruit Fast Version
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THC | 18% - 22% (Medium) |
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Type | Fast Flowering |
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Yield | High |
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Phenotype | 40% Indica / 60% Sativa |
Rock Start at a Glance
Before you plant anything, it helps to see the full picture in one place. Here is the quick profile for this Cup-winning indica-dominant feminized strain, taken straight from the strain’s grow data.
| Seed type | Feminized (photoperiod) |
|---|---|
| Genetics | Sensi Star x Rockbud |
| Awards | Cannabis Cup winner, 2012 |
| Phenotype | 70% Indica / 30% Sativa |
| THC | 15–22% (medium) |
| Flowering time | 8–10 weeks |
| Outdoor harvest | October |
| Height | up to 3.94 ft (1.2 m) |
| Yield indoor | 1.31–1.64 oz/ft² |
| Yield outdoor | 28.22–42.33 oz/plant |
| Climate | Temperate |
| Flavors | Earthy, Sweet |
| Effects | Creative, Giggly, Relaxed |
| Difficulty | Beginner-friendly |
These are feminized seeds, so every plant flowers female and you skip culling males. Its 70% indica makeup places it with the indica seeds, its Sensi Star and Rockbud blend keeps it among the hybrid seeds, and its heavy harvest earns it a clear spot with the high yielding seeds.
Promos & Deals
How to Germinate Rock Start Seeds
A healthy harvest starts at germination. The paper towel method is hard to beat: fold the Rock Start seeds inside two damp sheets, slide them between two plates, and keep them somewhere dark at 70 to 79°F. A taproot usually appears in two to five days.
Once the taproot is a few millimeters long, move each seed root-down about 1 cm deep into a small pot of light, airy medium. Keep it lightly moist rather than soaked, hold humidity around 65 to 70%, and give soft light while the first true leaves open. Its sturdy Sensi Star and Rockbud genetics make for a vigorous, dependable seedling.
Starter tips
- Use plain, lightly pH-balanced water (pH 5.5 to 6.5) for the first week.
- Keep seedlings warm and humid, but never waterlogged.
- Hold off on nutrients until the second set of serrated leaves appears.
Growing Rock Start in the Vegetative Stage
Rock Start likes a temperate climate and, as a 70% indica, it stays short and manageable at around 1.2 m. Keep it on 18 hours of light a day, aim for day temperatures of 68 to 79°F, and hold humidity around 50 to 60%. Its compact, sturdy frame is a big part of why it suits indoor tents and newer growers.
This is the stage to shape the plant. Because it yields so heavily for its size, topping and low-stress training really pay off: spread the canopy, build an even layer of bud sites, and the compact plant can carry the big harvest it is capable of. A short, even canopy is also easy to keep lit and ventilated.
Its compact frame and October finish make it a strong outdoor plant across much of the US, where its huge yield really shows:
- Southern California and the Southwest: the long, warm season lets its heavy outdoor plants fill out and pack on weight through October.
- Pacific Northwest and cooler states: its hardy indica genetics handle cool nights well and finish before the wet autumn sets in.
- Colorado and mountain states: its compact size and October harvest suit shorter, cooler mountain seasons.
Flowering and Buds of Rock Start
Indoors, flip Rock Start to a 12/12 light cycle to trigger flowering, which runs 8 to 10 weeks. Outdoors it ripens through October. As a 70% indica it has a short stretch after the flip, then settles into dense, chunky, resinous colas true to its Sensi Star heritage.
Through bloom, drop humidity to 40 to 45% and keep air moving so the tight flowers do not trap moisture. The buds build an earthy, sweet aroma and frost up heavily, which is part of what earned this cross its Cannabis Cup.
At 15 to 22% THC it sits comfortably in the medium range, so the effect is balanced rather than overwhelming, a creative, giggly and relaxing feel that is easy to enjoy.
Common Problems and Pro Tips
Rock Start is beginner-friendly, but its heavy yield and dense buds point to a few things worth watching.
- Support the weight: for a short plant it carries a lot of bud, so stake or net the branches late in flower so they do not bend under the load.
- Bud density and mold: its tight, resinous colas can trap humidity, so keep a fan moving and humidity below 45% late in flower.
- Feed the yield: a plant this productive is hungry, so feed steadily through the stretch and watch for signs it wants a little more as the buds swell.
Expert tip: build the structure early with topping and training so the compact canopy can hold its big harvest. Ease off nitrogen once the buds set, and let cool nights late in flower sharpen the resin and bring out color in this Cup-winning indica.
Aroma, Flavor and Effects
The nose is grounded and inviting: a deep, earthy base with a sweet, candy-like lift. It is rich and rounded rather than sharp, and it grows fuller as the buds cure.
The flavor follows the nose, earthy and sweet with a smooth finish. On the effect side it is creative, giggly and relaxing, an upbeat, social lift that settles into easy calm. Because THC is moderate at 15 to 22%, it stays balanced and approachable rather than heavy.
Dominant terpenes
Rock Start is shaped by four terpenes: Myrcene, Humulene, Pinene and Valencene. Myrcene lays down the deep earthy base, Humulene brings a woody, hoppy depth, Pinene a fresh pine lift, and Valencene a sweet, citrusy note that lifts the finish. Together they explain its earthy-sweet aroma and its upbeat, relaxing feel.
Nutrient Schedule
Treat the figures below as a starting map, not a rulebook. Rock Start is a hungry, heavy yielder, so read the plant first: tip burn means back off, while pale, slow growth means it wants a little more. All values use EC.
| Stage | EC |
|---|---|
| Seedling | 0.4–0.6 |
| Growth | 0.8–1.2 |
| Early flower | 1.2–1.4 |
| Full flower | 1.4–1.6 |
| Flush | 0.0–0.4 |
Keep the pH around 6.0 to 6.5 in soil and 5.5 to 6.0 in hydro so the roots can actually take up what you feed.
What to Do With Your Trim: Extracts and Hash
Rock Start frosts up with resin from its Sensi Star side, so its trim is well worth keeping, and a heavy plant leaves you plenty of it. The sugar leaves you take off while manicuring carry trichomes and suit Ice Water Hash, where cold water and agitation separate the resin heads into a clean, solventless concentrate. Pressing that hash into rosin keeps the earthy, sweet flavor intact, or you can run a solvent extraction if that is your setup. The bare stems will not extract, but chopped and composted they feed organic matter back into the soil for your next grow.
Harvesting, Drying and Curing Rock Start
Timing the harvest comes down to the trichomes. Grab a loupe and watch the heads turn from clear to milky white; a scattering of amber signals peak ripeness. Indoors this lands 8 to 10 weeks after the flip, and outdoors the plants are ready through October.
After the cut, hang the branches in a dark room at 59 to 68°F with humidity near 50% and gentle air movement. Slow beats fast: drying over 10 to 14 days protects the earthy, sweet aromas that define this strain. When the small stems snap instead of bending, move the buds into jars.
Cure in sealed glass, opening the jars daily for the first week to let moisture escape, then easing off as the aroma deepens. Two to four weeks of patience here is where the earthy, sweet flavor really comes forward, and it is the step most first-time growers rush.
Frequently Asked Questions
Did Rock Start win a Cannabis Cup?
Yes. Rock Start is a Cannabis Cup winner from 2012, which speaks to the quality of its Sensi Star and Rockbud genetics. That pedigree shows in its heavy resin, its earthy-sweet aroma, and its creative, giggly and relaxing effect, backed by a genuinely big yield for such a compact plant.
Is Rock Start easy to grow for beginners?
Yes, Rock Start is beginner-friendly. Its sturdy Sensi Star heritage makes it vigorous and forgiving, it stays compact at around 1.2 m, and it finishes in 8 to 10 weeks. The main thing a new grower should plan for is its heavy yield: support the branches and keep humidity down late in flower.
How long does Rock Start take to flower?
Rock Start flowers in 8 to 10 weeks once you switch it to a 12/12 light cycle indoors. Grown outdoors, it is ready through October. As a 70% indica it has a short stretch after the flip, then fills out into dense, resinous colas over the back half of bloom.
How strong is Rock Start?
Rock Start is a medium-strength strain, with a THC level of 15 to 22%. The effect is creative, giggly and relaxing, an upbeat, social lift that settles into calm rather than an overpowering one. That moderate potency makes it an easy, enjoyable strain for a wide range of users.
How much does Rock Start yield?
Rock Start yields heavily for its size, around 1.31 to 1.64 oz/ft² indoors and a genuinely big 28.22 to 42.33 oz per plant outdoors in good conditions. Topping, training the compact canopy, and supporting the branches are what push it toward the top of that range.
What does Rock Start taste and smell like?
Rock Start leads with a deep, earthy base and a sweet, candy-like lift. It is rich and rounded rather than sharp, straight from its Sensi Star and Rockbud roots. Both the smell and taste grow fuller as the buds cure slowly in the jar after harvest.
