Why We Use Veg Nutrients Through Early Flower

For photoperiod plants, run Veg A and Veg B through flower day 21, then switch to Bloom A and Bloom B on day 22. Count from the day you flip to 12/12, not from seed or first pistils. Autoflowers switch when the buds are about the size of your pinky nail.

Seedlings start lower and work up; the full schedule is on our feed charts.

Why Veg for the first three weeks

The lights change in a day. The plant doesn't. For the first three weeks of 12/12 the crop is still stretching and building stems, leaves and flower sites, and Veg gives the nitrogen and calcium balance we want for that growth. Both our Veg and Bloom use multiple calcium sources, so each formula sets calcium and nitrogen for its own stage. Bloom starts on day 22 because the plant's demand has changed by then, not because the light schedule did.

Day 22 doesn't move with veg length. Veg two weeks or two months, use Veg the whole time you veg and through day 21 of flower.

Common mix-ups

• Switched to Bloom at flip. Go back to Veg on the next feed and switch on day 22. You don't need to flush for that.
• Switching early to control stretch. Don't. Get the trellis in while the plants are small and check your light and environment instead.
• Running both pairs. One pair at a time. Never add Bloom A+B on top of Veg A+B.
• Splitting a pair. A and B always go in together, dissolved separately: A first, then B.
• Autos on day 22 from seed. Day 22 is a photoperiod flower day. Autos switch at pinky-nail buds.

If a cultivar finishes unusually early or runs much longer than a normal flower, send us the flower day and a bud photo and we'll set the switch for that cut. If you run short of Veg before day 22, bridge with the full Bloom pair, then go back to Veg when it arrives and still switch on day 22. See what to do if you run out of one part.

Watch the root zone around the switch

Root-zone pH can shift at the transition, because the crop takes up less nitrate and more potassium and phosphorus. Check feed and last-10% runoff pH and EC before and after the switch. A shift is not a reason to go back to Veg.

If symptoms show up right after the switch, look at what else changed then: light, stripping, irrigation or environment. If runoff pH drops from buildup in free-draining media, use the tap-water flush in why runoff pH is lower than feed pH.