How to Fertilize Garlic (What We Use and Why)
, by Earthwise Garlic, 4 min reading time
What fertilizer we use on our Oregon garlic farm, how much to apply per 100 square feet, why we split the application between fall and spring, and what happens when you apply too much or too little.
Garlic is a heavy nitrogen feeder. Get the fertilizer right and you get bigger bulbs, stronger plants, and better flavor. Get it wrong and you'll see it at harvest.
Here's exactly what we use on our farm in Coburg, Oregon, and how we apply it.
The fertilizer we use
We use Nature Safe 13-0-0, available through New Country Organics. It's a pelleted, high-nitrogen fertilizer made from feather meal, meat meal, and blood meal. The nitrogen releases slowly over 8 to 10 weeks, which lines up well with how garlic actually grows.
A few things we like about it:
The pellets don't catch the wind. Powdered fertilizers can drift when you apply them, especially on a breezy Oregon day. The pelletized form goes where you put it, right into the row or tilled into the bed before planting.
It's OMRI listed and approved for organic production. We farm without synthetic pesticides or fertilizers, and this product fits that approach.
The slow release means the plants get a steady feed rather than a spike. That matters for garlic, which is in the ground for months and needs consistent nutrition through both fall establishment and spring growth.
How much to apply
We apply roughly 2 lbs per 100 square feet over the season, split into two applications.
The first application goes in November at planting, about 1.5 lbs per 100 square feet. We either drop it directly into the rows or till it in just before planting. The goal is to get it into the root zone where the cloves can access it as they establish over winter.
The second application goes in February, about 0.5 lbs per 100 square feet. By then the shoots are up and the plants are starting to push growth. This lighter top-dress carries them through the spring growth season, which is when most of the bulb development happens.
Why split the application?
Garlic has two distinct growth phases. In fall it's putting down roots and establishing. In spring it's building the bulb. Each phase benefits from nitrogen, but putting it all down at once early in the season isn't as effective as feeding the plants when they need it.
Splitting also reduces nitrogen loss over winter. Oregon gets a lot of rain between November and February. A single heavy fall application can leach before the plants have a chance to use it.
Common questions
Can you apply too much fertilizer?
Yes, and it shows. Too much nitrogen, especially late in the season, pushes the plant to keep growing leaves when it should be putting energy into the bulb. You end up with tall, lush plants and small bulbs at harvest.
Excess nitrogen in spring can also delay the natural die-back of the leaves, which is how you know the garlic is ready to pull. If the plant won't stop growing, you won't know when to harvest.
Overfertilizing can also burn roots if the concentration gets too high around the cloves at planting. The pelletized form reduces this risk compared to raw blood meal or powder, but applying more than the recommended rate isn't worth it.
What happens if you apply too little?
Nitrogen-deficient garlic turns yellow from the leaf tips down earlier than it should. Plants look pale and thin. Bulbs come in small, wrappers can be loose rather than tight, and you'll tend to get fewer cloves per bulb and less weight at harvest.
If your garlic looked stunted last season and drainage wasn't the problem, fertilizer rate is worth looking at first.
Does the 13-0-0 provide phosphorus or potassium?
No. The 13-0-0 designation means 13% nitrogen, 0% phosphorus, 0% potassium. It's a nitrogen-only product. If your soil is low in phosphorus or potassium, you'd address those separately. A soil test before planting is the best way to know what your ground actually needs.
Is it safe for organic production?
Yes. Nature Safe 13-0-0 is OMRI listed and approved under USDA National Organic Program guidelines. We use it as part of our pesticide-free, naturally grown approach on our ODA inspected and licensed farm.
Where can you buy it?
New Country Organics sells it online in 50 lb bags at newcountryorganics.com. They also have a dealer locator if you'd prefer to source it locally.
One more thing
Fertilizer is one piece of the picture. Soil health, drainage, planting depth, and variety selection all play into how your garlic performs. If you're just getting started, our complete growing guide covers all of it from planting to harvest. And if you're ready to order seed garlic for fall planting, we ship all six of our heirloom varieties in September. Browse the full catalog here.