6 Common Reasons for Small Garlic (How to Grow Big Garlic)

Garlic is one of the easiest vegetables to grow, and although garlic can thrive in a variety of environments, those big garlic bulbs can be elusive. It’s normal to have garlic bulbs of different sizes, with some small and some large, but if consistently small garlic is usually a sign of some issue holding them back, such as insufficient watering or competition from weeds.

Why Your Garlic Bulbs Are Small – And How to Make Them Bigger

1. Big garlic needs room to grow – avoid overcrowding and weeds

As with most vegetables, keep your garlic bed weeded regularly. Garlic can (and should) be mulched after planting with at least 1 inch (2.5 cm) of straw or leaves to help suppress weeds.

Garlic is sensitive to competition, even among other garlics. Garlic grows best with a minimum of 3 inches (7.6 cm) of space between plants, with up to 5 inches (12.7 cm) being recommended. Even when planted closer together, garlic plants will thrive, but under the surface you can end up with undersized bulbs.

If planting garlic in containers or raised beds, give at least 2 inches (5 cm) of space between the edge of the container and your garlic to give the developing bulb enough space to grow.


2. Compacted soil and planting too deep can reduce garlic bulb size

Like all root vegetables, as garlic bulbs develop underground, they expand and displace the soil around them. If the soil itself is too compacted,

The best soil for garlic is sandy loam with lots of organic matter (compost). As most gardeners don’t have ideal soils, either too sandy or too heavy, amending your soil with compost is the easiest way to make it more suitable for growing garlic, as it both improves soil structure and adds nutrients and beneficial microorganisms to your garlic bed. 

For heavily compacted soil, loosen it up with a cultivator or shovel, and let the soil settle over a few days before planting.

Planting garlic too deep is another reason for small garlic bulbs, as the deeper you plant your garlic, the more soil pressure there is around the bulbs, making it harder for them to grow. Garlic should be planted about 1 to 2 inches (2.5 to 5 cm) deep.


3. Letting hardneck garlic scapes grow can make bulbs smaller

One of the benefits of growing hardneck garlic is that you get to enjoy an early harvest – hardneck garlic grows a curly flower stalk called a garlic scape. To maximize the size of your garlic bulbs, you should harvest your garlic scapes. They’re perfectly edible and have a mild garlic flavor but it can be described as fresh and slightly sweet.

Scapes draw energy away from the developing bulb. You can remove your scapes the moment they appear, but if you enjoy eating them, you can maximize the yield of your scapes and garlic bulbs by picking them after they make the first turn or curl.


4. Garlic planted too early or too late can end up smaller than average

The best time to plant garlic depends on where you live, but is around 3 to 6 weeks before your average first frost date. You can plant early spring garlic, but for best results, plant in the fall so you can harvest the following summer.

The reason for planting a few weeks before your first frost is to give your garlic cloves enough time to grow some roots and a small shoot before the frost comes and they become dormant. 

If you plant garlic too early or too late, you risk setting back your garlic in the spring, leading to smaller bulb development. Garlic planted too early will grow too much in the fall and waste energy that will be needed in the spring. On the other hand, garlic planted too late may not have enough time to develop a good foundation of roots to survive the winter and have a head start in spring.


5. Garlic requires consistent watering to develop full-sized bulbs

Garlic is tolerant of dry soil, but grows fuller, larger bulbs when it doesn’t go through dry periods. While too much water can cause bulbs to rot, too little water will stress garlic plants and reduce garlic yields.


6. Harvest garlic after lower leaves die back

It’s hard to know exactly when to harvest garlic, as it doesn’t ripen like most vegetables, and is edible at any stage of development. As a general rule of thumb, you want to harvest garlic as the plant is starting to die back, but before the whole plant has died back. When the bottom 3-4 leaves have turned yellow, up to approximately half of the plant’s leaves, that’s when you want to harvest your garlic. The top leaves should still be green or mostly green.

Waiting until the whole plant has died back can reduce the shelf life of your garlic bulbs and make them more vulnerable to rot.


How to Grow Big Garlic (Checklist)

Knowing what are the common causes of small garlic can help troubleshoot what went wrong in your garden. Below is a summary of all the things you can do to ensure bigger garlic bulbs next year.

  • Always plant your largest cloves. It seems counterintuitive to plant your best cloves instead of eating them, but on average, larger cloves will produce larger bulbs.
  • Plant 3 to 6 weeks before your average first frost date.
  • Give your garlic enough space. Plant cloves at least 3 inches apart.
  • Plant your garlic in loose, rich soil.
  • Garlic plants should not be allowed to dry out completely. Garlic grows bigger bulbs when the soil is evenly moist, and doesn’t completely dry out.
  • Don’t let your garlic compete with weeds. Weed regularly and use mulch if possible.
  • If growing hardneck garlic, remove the flower stalks (scapes). Scapes are also edible.
  • Harvest garlic when bottom 3-4 leaves up to half, have turned yellow or died back. 


Can You Replant Small Garlic Bulbs?

You can plant small garlic bulbs and see success. Separate the cloves and plant the largest ones to give yourself the best chance of growing bigger garlic next year. Even if you have only small garlic cloves, it’s worth planting them as you may end up with some garlic with big bulbs which you can save for replanting the following year. 


Why Your Garlic Hasn’t Split into Cloves

It’s one thing to have a small garlic bulb, but it’s another issue if your bulb hasn’t even split into individual cloves. After planting garlic cloves, it takes several weeks of cold nights (under 50°F/10°C) in order to ensure proper bulb development and splitting into new cloves.

If garlic hasn’t split into cloves and is just one big (or small) clove, it’s likely that it either went through a very mild winter that didn’t get cold enough or it was planted too late and didn’t have enough time under cold conditions to split into cloves.