Growing
Growing Rainbow Runtz: flowering time, yield and breeder specs
Seed versions of Rainbow Runtz flower in about 9 weeks according to Wizard Trees and Philosopher Seeds, and in 8–10 weeks according to Weedmaps and Growers Choice; Hypno Seeds’ autoflower is ready 8–9 weeks from germination. Each seller’s version is a different cross, so yields and heights vary with the seed.1,2,3,4,5
Breeder specs side by side
| Source and version | Flowering | Indoor yield | Outdoor | Difficulty |
|---|---|---|---|---|
| Wizard Trees, feminized (Runtz × RS11) | 9 weeks | Medium to heavy | —1 | — |
| Exotic Genetix, feminized (Rainbow Chip × Runtz); retired | Not published | Heavy; medium to tall, grown as a multi-topped bush | —6 | — |
| Philosopher Seeds, feminized (Runtz × Kush Mints) | 9 weeks | Over 400 g/m² | Early October; over 500 g per plant2 | Easy to grow2 |
| Growers Choice, feminized (lineage unconfirmed) | 8–10 weeks (±63 days on SeedFinder) | A good yielder, reportedly | —4 | — |
| Nugs 420, feminized (Zkittlez × reversed Runtz) | About 60 days | Not published | —7 | — |
| Hypno Seeds, autoflower | 8–9 weeks from germination | 1.5–1.8 oz/ft²; 27–50 in tall | End of September to early October; 2.1–7.4 oz per plant5 | Beginner-friendly5 |
| Weedmaps (strain page) | 8–10 weeks | 450–650 g/m²; 3–5 ft | 14–20 oz per plant; 5–7 ft3 | Moderate3 |
Seed-company figures are the sellers’ own claims, and each version is a different cross.
What the plant is like
Growers Choice says the plants typically look indica-dominant, short and bushy with broad dark-green leaves; they stay compact with tight internodes in veg, then stretch considerably once they flower, and some versions turn purple and pink while others stay lime green.4 Philosopher Seeds describes compact flowers that take on dark violet tones late in flowering, Wizard Trees dark, colorful flowers with contrasting pistils, and AllBud heart-shaped olive-green buds with purple undertones and red-orange hairs.1,2,8
What to watch for
Smell, weight and moisture. Philosopher Seeds recommends a carbon filter indoors for the strong odor and staking or trellising the branches under the heavy colas; Hypno Seeds says airflow is essential because the dense buds can trap moisture, and that its fast autoflower does not recover well from early mistakes.2,5,9 Weedmaps suggests 68–80°F and humidity around 40–50% in flower, and Growers Choice says cool temperatures may bring out purple hues in some versions.3,4
Seeds and the law in the US
Under the amended federal definition of hemp, viable seeds from cannabis plants above 0.3% total THC, including THCA, are not hemp.10 Congress delayed that exclusion, with most of the new definition, from Nov 12 to Dec 11, 2026; only the exclusion of products with cannabinoids the plant cannot produce naturally starts on Nov 12.11 Home cultivation rules are set by each state. This site does not sell seeds.
Sources
- SeedFinder, Rainbow Runtz (Wizard Trees): strain info and breeder description. Accessed Oct 4, 2026.
- Philosopher Seeds, Rainbow Runtz (feminized seeds). Accessed Oct 4, 2026.
- Weedmaps, Rainbow Runtz (aka Rainbow RZ) strain page. Accessed Oct 4, 2026.
- SeedFinder, Rainbow Runtz (Growers Choice): strain info and seller description. Accessed Oct 4, 2026.
- Hypno Seeds, Rainbow Runtz Auto (autoflower seeds). Accessed Oct 4, 2026.
- Exotic Genetix, Rainbow Runtz (Retired). Accessed Oct 4, 2026.
- SeedFinder, Rainbow Runtz (Nugs 420): strain info. Accessed Oct 4, 2026.
- AllBud, Rainbow Runtz marijuana strain information and reviews. Accessed Oct 4, 2026.
- SeedFinder, Rainbow Runtz (Philosopher Seeds): strain info. Accessed Oct 4, 2026.
- Congressional Research Service, Changes to the statutory definition of hemp and implications for agricultural policy (IF13136) (2026-09-28). Accessed Oct 4, 2026.
- U.S. Government Publishing Office, Continuing Appropriations and Extensions Act, 2027 (P.L. 119-103), sec. 2019. Accessed Oct 4, 2026.