Growing automatic plants in mother plant cabinets

The autoflowering varieties come from crosses with Cannabis ruderalis and are characterized by flowering according to their age rather than the photoperiod. This means they begin to form flowers between the second and fourth week after germination, regardless of the number of hours of darkness they receive.

This pattern makes them especially interesting for mother plant cabinets or small auxiliary cabinets because you can maintain a long and stable light cycle for your conventional mother plants—such as 18 hours of light and 6 hours of darkness—while also growing autoflowers that will complete their cycle in about 10–12 weeks without needing to change the timer.

Compared to classic varieties, automatic plants tend to be more compact, faster and less tolerant to stress, but they allow several harvests per year in very small spaces and without complications related to photoperiod changes.

Choosing a mother plant cabinet and planning the space

A typical mother plant cabinet is a grow tent measuring between 60x60 and 80x80 centimeters at the base and between 140 and 200 centimeters tall, designed to maintain mother plants and cuttings under a long photoperiod.

To integrate autoflowers into the same space, it is advisable to reserve a lower or side area for potted plants and keep the upper part more open for the mothers, always leaving at least 40–60 centimeters between the top of the plants and the light to avoid light stress and burns.

It is also important to check the extraction capacity; grow tent manufacturers recommend renewing the air volume inside the tent at least once per minute.

Light configuration in a mixed cabinet with autoflowering plants

Autoflowering plants work well with photoperiods between 18/6 and 20/4 hours of light and darkness.

In vegetative growth cabinets, 18/6 is the most common because it offers a good balance between performance and energy consumption.

In a mother plant cabinet, lighting is usually blue-spectrum LED to promote compact vegetative growth. If you are going to grow autoflowers in the same cabinet, it is better to choose full-spectrum LEDs that cover from blue (400/500 nanometers) to deep red (660 nanometers).

Climate control and air renewal

Autoflowers share with any indoor variety an optimal temperature range of around 24–26 ºC during the light cycle and 20–22 ºC in darkness.

Relative humidity should range between 60/70% in seedling stage, 50/60% during vegetative growth, and 40/50% in late flowering to minimize botrytis and fungal issues.

A mother plant cabinet usually already has an extractor with a carbon filter, a passive or active intake, and internal fans. Introducing autoflowers increases biological activity and heat production, so it may be necessary to slightly increase the extraction capacity.

Cannabis grow room ventilation

Grow room ventilation is a key aspect in any cannabis indoor grow room. In this post we tell you what you should know about how to correctly ventilate your growing space and get the best out of your plants.

Substrate and pot volume for autoflowers in a mother plant cabinet

Autoflowering plants have a limited growth window, so any root stress results in small plants. Therefore, it is recommended to plant them directly into their final pot, avoiding intermediate transplants that could slow their development.

In mother plant cabinets where space is limited, pots of 7 to 11 liters with an airy substrate usually work well.

To remain compatible with the mothers, some growers choose organic substrates enriched with worm humus, compost, and slow-release fertilizers, which reduces the need for intensive liquid feeding and simplifies irrigation.

Watering and nutrient management specific to autoflowering plants

Autoflowers usually require slightly lower fertilizer doses than photoperiod-dependent plants.

In a mother plant cabinet where a standard nutrient solution might be used for your mother plants, you can prepare a separate tank or container for the autoflowers to avoid overfertilizing young cuttings. Remember that autoflowers start demanding less nitrogen and more phosphorus and potassium from the third or fourth week, when flowering appears.

Coexistence with mother plants and cuttings in the same cabinet

The key for a mother plant cabinet to also function as a small autoflower flowering room is proper space and schedule organization.

Mother plants require constant maintenance—light pruning, pest control, and renewing cuttings—while autoflowers follow a more or less fixed cycle of around 10 weeks.

It is important to maintain hygiene protocols: any pest present on the mothers can jump to the autoflowers and ruin an entire cycle. An integrated pest management program should combine visual inspection, sticky traps, biological prevention, and gentle treatments.

Cycle monitoring and harvest timing in autoflowering plants

Most autoflowers are ready to harvest between 70 and 90 days after germination, although there are fast phenotypes that finish in about 8 weeks and others, more sativa-leaning, that take a bit longer.

Beyond the calendar, the most reliable indicator is trichome maturity, observed with a magnifying glass or microscope of at least 40x. When most trichomes turn from transparent to milky, the plant is considered to have reached its peak potency.

Common mistakes when growing autoflowering cannabis in mother plant cabinets

One of the most common mistakes is treating autoflowers like long-cycle photoperiod plants. This results in multiple transplants, aggressive pruning, and sudden photoperiod changes that shorten their vegetative phase even more, producing very small plants.

Philosopher Seeds insists that autoflowers should suffer as little stress as possible during the first four weeks. Another common mistake is overcrowding the cabinet, assuming the plants will stay small; in reality, many modern autoflowers can easily reach 70–100 centimeters in 11-liter pots.

Growing autoflowering strains from Philosopher Seeds

In this new post we present a hydroponics growing report of the autoflowering strains of our Auto Line. You will see the development of the crop until the end of flowering, with detailed information on each variety. We also present an easy and simple growing system, with which you can obtain first-class cannabis buds.