Runtz strain: every version compared

Which Runtz should you grow?

The right Runtz comes down to space and patience: strength is high on most versions, so choose on the rest.

Photoperiod or autoflower? Photoperiods give the full plant, run on a timer across 55–63 days of bloom, and list THC 21–29%. Autoflowers finish on their own clock from seed, 56–70 days, and list 23–28%, and here the biggest listed yield on the page belongs to an auto, so the photoperiods are not automatically the heavier choice. For a first grow, an auto means one less thing to time.

How much headroom have you got? Runtz stays contained throughout, but the types do not line up the way you might expect. The photoperiods are listed at 110–120 cm, the autos at 120–150 cm. Sort the table by height if space is tight.

Runtz photoperiod (feminized)

The photoperiod versions are the full Runtz: you cut the light to 12 hours to flower once the plant is the size you want, paying the control back in candy-sweet, resin-coated flower. Flowering runs 55–63 days, with listed THC 21–29%. Heights are listed at 110–120 cm.

Runtz autoflower

Runtz comes autoflowering as well, flowering on age with no light switch to time: a sweet hybrid on the simplest possible schedule. There are 4 autos here, and they keep the sweet, fruited Runtz character while finishing on their own time. Seed-to-harvest runs 56–70 days. The autos are listed at 120–150 cm: read the figure, since type alone will not tell you. Top listed THC on them is high, 23–28%, right alongside the photoperiods. Breeders lean on a Super Auto or Sweet Gelato Auto line to set the automatic clock, and Sweet Seeds say theirs was years in the making, a proper autoflowering Runtz rather than an approximation. If you are new to growing and want Runtz without a light schedule, begin with the autos, and leave a little room for the taller ones.

How Runtz grows

Barney's say their Runtz smokes like a hybrid but grows almost entirely like an indica, and they put that down as the grower's advantage: short, hardy, and the sort you forgive readily as she grows. Their feminized cut is listed at 55 days and a manageable 110 cm, with a listed 600 g/m².

Patience and height are where the versions part. EGS say theirs asks little in the way of maintenance yet returns high yields. Growers Choice list their feminized at 60 days. Sweet Seeds' auto is the quick, colourful one: listed at a brisk 56 days from seed and 120 cm. EGS go the other way: a longer auto, 70 days from seed and 150 cm, that asks for patience and a little room. Herbies list their feminized at 120 cm and their auto at 130. So read the height on the version you are buying; an auto here is not automatically the shorter one. The span runs 110–150 cm across the family.

The real pleasure of growing her is the finish. Sweet Seeds note the buds put on a rainbow of colour as they ripen. Barney's describe thick, dense buds, absolutely dripping with resin. Give the taller autos room and let the colour come in its own time, and Runtz can be an easy plant with a good-looking harvest at the end.

Where Runtz comes from

Runtz is a modern name with a short pedigree, and the catalogue mostly agrees on it. The pairing that made Runtz a household name is Zkittlez crossed with Gelato: Zkittlez brings the fruit, Gelato the creamy sweetness, as Barney's Farm put it. Breeders word it a few ways, Z crossed with Gelato, or Gelato 33 crossed with Z, but it lands in the same place. Breeders split her close to even and a touch indica. Each version's page gives the cross in its own breeder's wording.