Tomatoes get fed in stages, and most of the confusion comes down to two questions: when to move from Veg to Bloom, and what to do about blossom-end rot. This is the practical version. A simple schedule from transplant to harvest, an honest look at what calcium can and can't do, and the one thing that fixes blossom-end rot more often than any bag of anything.
The Short Version
- Feed Veg from transplant until the plant is about to flower. Switch to Bloom when the first flower clusters set.
- Add King Krustacean at 1/4 tablespoon per gallon. It brings calcium to the soil, but it does not guarantee you won't get blossom-end rot.
- Blossom-end rot is mostly a watering problem. Fix the watering first.
- Microbes go in every feed. Veg and Bloom need them to work as designed.
What Blossom-End Rot Actually Is
Blossom-end rot is a dark, sunken, leathery patch on the bottom of the fruit, the end opposite the stem. It usually shows up on the first fruit of the season and is most common on paste and plum types, though any tomato can get it.
The cause is the fruit not getting enough calcium while it is growing. That is not the same as the soil lacking calcium. Calcium moves through the plant with the water stream, and the developing fruit is the last place it arrives. When water uptake swings, the fruit loses out.
The usual triggers, in rough order of how often they cause it:
- Uneven watering: dry spells followed by a soaking.
- Containers that dry out fast, especially in heat.
- Root damage from cultivating close to the plant.
- Very fast leafy growth from heavy nitrogen, which pulls water and calcium toward leaves.
- Salt buildup in the soil that makes it harder for roots to take up water.
Affected fruit does not heal. Pick it off, fix the cause, and later fruit is often clean. Soil calcium alone doesn't cure it. If your soil test already shows plenty of calcium and you still get blossom-end rot, more calcium is not the answer.
Tomato Feeding Stages
Here is the stage plan, from transplant through harvest.
- Transplant: Microbes and Kelp It Real. Microbes go in the same day you plant. Kelp is for transplant stress.
- Vegetative growth, transplant to pre-flower: Veg, Microbes and King Krustacean. Veg dose is 1/4 to 1/2 tablespoon per gallon.
- Flower set: switch Veg to Bloom, and keep Microbes and King Krustacean. Stop Veg once Bloom starts. Add Kelp It Real for fruit set.
- Fruit fill and harvest: Bloom, Microbes and King Krustacean. Keep the schedule going while fruit sizes up.
Per-gallon doses from the feeding chart:
- Veg: 1/4 to 1/2 tablespoon
- Bloom: 1/4 to 1/2 tablespoon
- King Krustacean: 1/4 tablespoon
- Kelp It Real: 1/4 teaspoon
- Microbes: 1 to 3 ml
One feeding is one US gallon mixed at the base dose. If a plant needs more than a gallon, scale the volume of water and keep the dose per gallon the same.
Timing depends on where you live. In most of the US, transplant after the last frost when nights stay warm. For a week-by-week program, pick your plant on the feeding schedule page. Flower set depends on variety and weather, so go by the plant, not the date.
Calcium: What King Krustacean Does and Doesn't Do
King Krustacean's guaranteed analysis is 1.6-0-0.9 with 10% calcium and 8% humic acid from leonardite. It is made from crustacean meal, seaweed and potassium hydroxide. The calcium is the reason it is our tomato product.
What it does: it adds calcium to the soil and gives the chitin-eating part of the soil biology something to work on. Humic acid helps with nutrient exchange and soil buffering.
What it doesn't do:
- It doesn't prevent blossom-end rot. If water is swinging, calcium in the soil can't get into the fruit reliably.
- It isn't a pesticide. We make no pest or disease treatment claim for it. At most it supports soil biology and plant resilience.
- It isn't for houseplants, lawns or flowering ornamentals. It is a fruiting-vegetable product.
Two safety notes. King Krustacean is made from crab shell, so it isn't vegan. The label caution reads: may cause intestinal distress if swallowed. Store it out of reach of children and pets.
What to Do, Step by Step
- Water first. Water deeply and on a steady rhythm. A commonly cited rule of thumb is about an inch of water a week in the ground, more in heat, but check the soil with your finger rather than the calendar.
- Mulch the bed to hold moisture level. In pots, use a bigger container and water on a schedule you can keep.
- Plant, then inoculate the same day. Add Microbes to the transplant water. Don't wait for the bed to settle.
- Mix in this order: water, Microbes, then powder. Add the Veg or Bloom powder after the Microbes are in the water.
- Feed Veg through the vegetative stage. Add King Krustacean at 1/4 tablespoon per gallon alongside it.
- Watch the first flower clusters. When they set, stop Veg and start Bloom. Keep Microbes and King Krustacean going.
- Give Kelp It Real at 1/4 teaspoon per gallon around fruit set and transplant.
- Don't overdo nitrogen. A tall, dark-green, leafy plant with few fruit is a sign to back off, and it also raises blossom-end rot risk.
- If blossom-end rot shows up, remove the affected fruit, check watering, and test your soil for calcium and pH before adding anything.
Where Growganica Fits
For a tomato bed, the working set is Microbes, Veg, Bloom, King Krustacean and Kelp It Real. Veg and Bloom are designed to work with Microbes, so Microbes are not optional with them.
If you only want to add one thing for tomatoes, King Krustacean is the one that is built for them. But it sits on top of consistent watering. It doesn't replace it.
If your plants aren't fruiting vegetables or fruit, such as houseplants, skip King Krustacean. Kelp It Real is the better fit there. And if your real problem is watering, none of our products will fix that, and we'd rather tell you so.
Frequently Asked Questions
What causes blossom-end rot?
Blossom-end rot happens when the fruit does not get enough calcium while it is growing. That is different from the soil lacking calcium. Calcium travels with the water stream, and the developing fruit is the last place it arrives, so when water uptake swings, the fruit loses out. The usual triggers are uneven watering, containers that dry out fast, root damage from cultivating close to the plant, very fast leafy growth from heavy nitrogen, and salt buildup in the soil.
When do I switch tomatoes from Veg to Bloom?
Watch the first flower clusters. When they set, stop Veg and start Bloom, and keep Microbes and King Krustacean going. Flower set depends on variety and weather, so go by the plant, not the date.
How much King Krustacean do I use per gallon?
1/4 tablespoon per gallon. One feeding is one US gallon mixed at that dose. If a plant needs more than a gallon, scale the water and keep the dose per gallon the same.