Grandmommy Purple Seeds

Genetics & effects

Grandmommy Purple is a feminised, indica-dominant cross of Big Bud × Purple Urkle, listed at approximately 80% indica and 20% sativa. The catalogue figures indicate 27–33% THC and 0–1% CBD, suggesting a notably potent cannabinoid profile. Individual plants and finished flowers can vary according to phenotype, environment, timing, and cultivation technique.

Its aromatic profile combines sweet grape and berry notes with earthy, woody depth. Myrcene, caryophyllene, and pinene are the principal listed terpenes. Some consumers describe the experience as powerful, calming, happy, and deeply relaxed, with sleepy or hungry sensations sometimes reported later. These impressions are subjective and may differ considerably from person to person.

Explore feminised seeds, high thc seeds, the New Zealand grow guide, and the planting calendar.

Explore feminised seeds, high thc seeds, the New Zealand grow guide, and the planting calendar.

Growing in the named country

Presented in the Kiwi Seed Bank catalogue for New Zealand growers, Grandmommy Purple is considered an intermediate-level option. It is suited to temperate conditions and hot, dry environments, though New Zealand’s regional variation means growers should plan around local humidity, rainfall, wind, and night temperatures. Good airflow and attentive moisture management can reduce the risk of mould, particularly in damp coastal districts.

For an outdoor cycle, spring planting generally falls between September and November. Select a sunny position with freely draining growing media and shelter from severe winds. Regular observation is useful as plants move through late summer and autumn, when heavier flowers may need physical support.

Indoor

Indoors, plants are listed as reaching up to 120 cm. The moderate height can suit tents and dedicated grow rooms, while pruning, topping, and canopy training may help use available light efficiently. Allow enough lateral space for branching and maintain steady air exchange around the foliage.

The listed flowering period is approximately 9–10 weeks. Indoor yields are stated as up to 600 g/m² under favourable conditions, but this is an upper reference rather than an assured outcome. Light intensity, root space, nutrition, plant health, and grower experience all influence final performance. Cooler late-flowering temperatures may encourage deeper purple colour in some phenotypes.

Outdoor

Outdoors, Grandmommy Purple is listed at up to 180 cm, making site selection and privacy planning important. In warm, sunny positions, plants may develop substantial branches and weighty flower clusters. Stakes, ties, or netting can help support the canopy as flowers gain mass.

Potential outdoor production is listed as up to 1,000 g per plant in favourable settings. Actual results vary widely. In wetter areas, keep the centre of the plant open, avoid persistent leaf crowding, and inspect dense flowers after rain. Its sweet grape aroma may become pronounced, so consider airflow and nearby spaces when choosing a location.

Harvest

In New Zealand’s southern-hemisphere cycle, outdoor harvest generally falls between March and May, depending on planting time, latitude, phenotype, and seasonal weather. Watch flower development rather than relying solely on the calendar. Indoor plants are typically ready after the listed 9–10-week flowering window.

At harvest, expect dense flowers with possible purple colour, sweet berry character, and earthy undertones. Handle heavy clusters carefully, remove excess plant material, and dry them slowly in a dark, ventilated space with stable conditions to preserve their distinctive aroma and appearance.