Bloom Phase
Veg to Bloom
Plants begin budding when switched to at least 12 hours of uninterrupted darkness each night (”12/12”). This must continue until harvest.
When to switch to bloom?
There are 2 main considerations:
- Strong root system: Cuttings usually need at least 2-3 weeks in veg. “Seedlings” generally need 6-8 weeks. Alternatively, they can be switched straight after germination, however they are biologically incapable of budding until about 3 weeks of age. Growth-XS will accelerate veg and prevent stalled growth.
- Height of plant: Plants will typically double in size during flowering. So, if ‘room’ height is limited, switch to 12/12 before the plant has reached 50% of the ‘available’ height. Topping and LST (see section) are very useful techniques for keeping plants short and bushy and will help enable a long veg (6-8 weeks) if required.
Bloom Phase
As a rule-of-thumb, in the first 2-3 weeks of flowering the plant will continue to grow in height (termed “flowering-stretch”) and buds will begin to form. Following this, floral growth will dominate and veg growth will slow then stop. Some general principles:
1. Refer to ‘Bloom’ phase on the FloraMax Dose Chart. Resin-XS, OrganaBud and Flowering Enhancer are key for maximizing yield and quality. For coco, soil or Rockwool, ensure feeds are frequent and with enough run-off (Table 10.3).
2. Switch lights off for 12 hours per day. If interrupted, flowering will be hindered, and plants may revert to veg. Employ a timer to help ensure consistency. NOTE: For outdoor grows, light deprivation techniques will need to be employed to trigger flowering when nights are too short.
3. Increase the air-exchange rate. Gradually lower relative humidity to around 40–60%. This helps avoid rot and mildew, and improves CO2 levels. See Table 10.3 for optimum VPD.
4. General optimum “daytime” temperature is 68-82 deg F (20-27 deg C).
5. To avoid stretch and maximize yields. Many growers complain that their plants ‘stretch’ excessively, especially in the first 2-3 weeks of flower. Along with potentially reduced yields, lower foliage will be more difficult to light efficiently, and top foliage is at risk of being burnt if lamps cannot be raised any higher. Plants can also be gangly and weak and therefore susceptible to breaking once loaded with buds. Although “flowering-stretch” is biologically unavoidable, there are ways of minimizing it:
- Ensure optimum PPFD (see Table 10.3). Generally, keep plants as close as possible to the lights without causing burning.
- At “night” do not allow the temperature to drop by more than 9 deg F (5 deg C).
- Avoid shading by having too many plants.
- FloraMax Silica will help stems carry fruit weight.
6. Avoid stressing plants by pruning during flowering. Major structural pruning should be done during veg.
© Andrew M Taylor (FloraMax)
