We’re in the fall, which is the best time to plant garlic in the northern hemisphere. Garlic is fairly simple to grow, but if you’ve never grown it before, or had disappointing harvests in the past, don’t miss this list of common garlic growing mistakes!
1. Choosing The Wrong Clove Size
The biggest garlic cloves grow the biggest bulbs, giving you more garlic to enjoy. When you break up your heads of garlic, choose the large and medium-sized cloves for planting. Save the smallest cloves for the kitchen.
If space isn’t an issue in your garden, plant the smaller cloves as well, then either harvest those garlic plants in the spring (like green onions) or let them grow until maturity when they’ll give you small heads of garlic.
The young, spring-harvested shoots are full of flavor and make a delicious addition to salads, soups, and stir fry.
2. Planting The Wrong Variety For Your Growing Zone
Garlic comes in two main kinds. Hardneck garlic, and softneck garlic.
Hardneck garlic is best for cold climates. Softneck garlic grows best in warmer zones.
If you plant the wrong type of garlic for your climate zone, your fall-planted garlic could die during the winter.
Growing the wrong kind of garlic can also result in small bulbs, bulbs that don’t form cloves, or bulbs that won’t cure properly for storage.
To get the best harvest, use the type best suited to your growing zone.
| Aspect | Hardneck Garlic | Softneck Garlic |
|---|---|---|
| Climate Suitability | Hardneck garlic is cold-hardy, able to tolerate overwintering in harsh climates down to USDA growing zone 0. | Softneck garlic grows best in climates with hot summers and mild winters. USDA zones 8 to 12. |
| Needs Cold Weather Exposure? | Yes. Hardneck garlic needs to go through vernalization (exposure below 40F for at least 40 days after planting). Without vernalization, hardneck garlic forms one small bulb instead of a head with multiple cloves. | No. Softneck garlic doesn’t require exposure to low temps, and is best planted in the spring in colder regions. It matures faster than hardneck garlic, making it suitable for a shorter growing period. |
| Skin | Hardnecks typically have thicker, more brittle skin, which is easier to peel. | Softneck garlic tends to have papery skin, making it more challenging to peel. |
| Flavor | Hardnecks have stronger and more complex flavors than softneck varieties. | Softneck garlic has a milder flavor than hardneck. This is the garlic sold in most supermarkets. |
| Clove Size | Hardneck varieties tend to form fewer cloves per bulb, but they are usually nice big cloves. | Softneck garlic offers more smaller cloves per head. Depending on the variety, heads can produce anywhere from 8 to 20 cloves. |
| Edible Flower Stalk (Scape) | Only hardneck garlic produces the edible flower stem called a garlic scape—a delicacy that can be pickled or added to a range of foods for a mild garlic flavor. | Softneck garlic does not produce a garlic scape. |
| Shelf Life | Hardneck garlic has a shorter shelf life, lasting 3 – 5 months when stored properly. | Softneck garlic has a much longer shelf life. Stored properly, it will keep for 8 – 12 months. |
Hardneck garlic comes in 8 different types, each type having many cultivars:
- Asiatic
- Creole
- Purple Stripe
- Glazed Purple Stripe
- Marble Purple Stripe
- Porcelain
- Rocambole
- Turban
Softneck garlic has 2 types, silverskin and artichoke.
3. Planting In The Same Spot As Last Year’s Garlic
Planting garlic in the same spot year after year can lead to a buildup of diseases and pests in the soil. It’s best to rotate your crops and plant garlic in a new spot each year.
A traditional rotation plan puts garlic (and other alliums) in a 3-year rotation with plants from the brassica family and plants from the nightshade family.
Brassicas include cabbage, sprouts, kale, broccoli, cauliflower, etc.
The nightshade family includes potatoes, tomatoes, eggplant (aubergine), sweet peppers, and chili peppers.
The allium family includes garlic, onions, leeks, chives, scallions, and shallots.
The rotation works like this. Brassicas first, followed by alliums, followed by nightshades, then repeat.
You could grow broccoli in a planting bed in year 1, then garlic in year 2, followed by tomatoes in year 3.
Other types of crop rotation are possible, and garlic can even be planted as a succession crop, following on from your harvest of summer squash or green beans, for instance.
4. Planting In Shade (Common Garlic Growing Mistake)
Garlic needs plenty of sunlight. Make sure you choose a sunny spot in your garden that receives 6 to 8 hours of sunlight a day.
If you plant in the shade, your garlic might not sprout any growth above ground, and if it does, it will struggle to grow and produce small bulbs.
When you’re planting garlic in the fall, that sunny spot might not be so sunny come spring, once the trees are in leaf.
5. Not Preparing Your Soil Properly
Garlic thrives in well-drained soil with plenty of organic matter.
Failure to ensure fertile soil before planting garlic leads to stunted growth.
If you plant in heavy soil that holds too much moisture, the bulbs could rot in the ground.
Think about planting your garlic in a raised bed filled with compost or a mix of soil and compost. Compost drains well, and with its built-in fertility, makes an ideal growing medium for garlic.
Garlic prefers a neutral soil pH (a measure of how acidic or alkaline soil is). A pH between 6.0 to 6.5 is ideal for garlic, but it will grow happily in soils as high a 8.0.
Compost has a pH ranging from 6.0 to 8.0 which is another reason to grow your garlic in soil with added compost.
Garden soil that’s a little on the acidic side, below 6.0, can be amended with a small addition of horticultural lime in the fall.
If your soil is heavy and wet during the winter, plant your garlic in module trays or small pots. Place the modules in an unheated greenhouse or cold frame for overwintering, then plant out in the spring.
6. Not Controlling Weeds Before Planting
Not controlling weeds is a big garlic-growing mistake!
Weeds will compete with garlic for nutrients, water, and sunlight. Because garlic has fairly shallow roots, it can’t mine deep into the soil to find the nutrients it needs.
Any weeds growing among your garlic will quickly invade the root zone, stealing the nutrients the garlic needs.
Remove the weeds in your garlic bed before you plant and keep the bed weed free.
Neglecting this step will have detrimental effects on the growth and development of your garlic crop. If you don’t keep on top of weed growth, you’ll have stunted growth, increased susceptibility to diseases, and reduced yields.
Here’s why weed control is so essential at all stages of garlic cultivation:
- Nutrient Competition
When weeds grow, they consume the nutrients present in the soil. Allowed to proliferate unchecked, weeds absorb essential nutrients that garlic plants need for healthy growth. Nutrient competition leads to nutrient deficiencies in garlic, affecting its overall development and reducing the quality of the harvest. - Water Competition
Weeds have an extensive root system giving them the ability to steal the water your garlic needs. In dry weather, weeds will out-compete garlic for this essential moisture, leaving the garlic plants stressed. Stressed plants are more vulnerable to diseases and pests. With proper weed control, all the soil moisture in your growing bed is available for your garlic plants. - Sunlight Interference
Weeds block sunlight, interfering with the photosynthesis process crucial for garlic bulb formation. Garlic plants require ample sunlight to produce healthy bulbs. Weeds overshadow garlic and limit the amount of light reaching the garlic plants. A weed-free growing bed ensures maximum sunlight for your garlic, promoting robust growth. - Disease Prevention
Weeds often harbor pests and diseases that could affect your garlic crop. Allowing weeds to thrive increases the risk of these issues spreading to your garlic plants. A weed-free garlic bed minimizes the potential for disease transmission and helps create a healthier environment for your garlic crop.
Before you plant, use a garden fork to work through the soil and lift up weeds.
Keep an eye on your garlic bed and pluck out any weeds by hand when they’re small. Removing weeds while they’re small won’t disturb the growing garlic.
If you’ve planted fall garlic, you shouldn’t have too many problems with weeds for a few months, but watch out once spring arrives.
One way to avoid dealing with weeds is to plant your garlic cloves through a weed-suppressing membrane. Cut slits in the weed barrier, then push the cloves into the soil through the slits.
7. Removing The Skin (Another Major Garlic Growing Mistake)
The skin, or inner peel, protects the clove and helps it sprout. Don’t remove the skin before planting.
Removing the skin is a common mistake that can have adverse effects on the garlic’s ability to establish itself and thrive. Here’s why it’s important to leave the skin intact when planting garlic.
- Protective Barrier
The skin covering a garlic clove serves as a natural protective barrier, shielding the clove from soil-borne pathogens, pests, and environmental stressors. If you remove this protective layer, you’ll increase the risk of infection and damage during the early stages of growth. - Moisture Retention
The skin on a garlic clove helps it retain moisture during the initial stages of growth as it establishes roots and begins to sprout. If you remove the skin, the garlic clove can dry out and hinder the garlic’s ability to develop a strong root system. - Nutrient Preservation
The skin of a garlic clove contains nutrients vital for the early stages of growth. By keeping the skin intact, these nutrients are preserved and available to the developing garlic plant. Removing the skin prematurely will result in nutrient loss, potentially impacting the garlic’s early growth and development.
Here’s a line from a research paper on garlic titled “What Worth the Garlic Peel.”
… the garlic peels not only provide physical protection to vegetative offspring but also appear to function as a refined arsenal of proteins and metabolites for enhancing growth and development, combating potential pathogens, and conferring tolerance to abiotic stresses.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8875005/
8. Planting Cloves Too Closely
Garlic needs space to grow. Planting cloves too closely can result in smaller bulbs, and increases the risk of disease,
Planting garlic cloves close together might seem like a space-saving strategy, but garlic doesn’t like to be crowded. It needs room to grow and thrive.
Problems that can arise from close planting.
- Competition for Resources
When cloves aren’t spaced out properly, they end up competing for nutrients, water, and sunlight. This competition stunts the growth of individual plants and often results in smaller bulbs. - Increased Risk of Disease
Crowded garlic plants create a more favorable environment for the spread of diseases. Reduced airflow between the plants leads to increased humidity, which can give rise to fungal infections, like white rot and rust. Proper spacing allows plenty of air circulation and reduces the risk of these diseases. - Small Heads of Garlic
Garlic needs room to expand as it grows. If cloves are planted too closely, the bulbs won’t have the space they need, resulting in smaller, underdeveloped garlic bulbs. Adequate spacing allows each plant to reach its full potential.
Plant garlic with at least 6 inches between the cloves in a row and between the rows in your planting bed. To save space garlic is often planted in double or triple rows.
Take a stick and mark off intervals of 6 inches to help you maintain regular spacing.
If you’ve got plenty of space, planting garlic cloves 8 inches apart limits competition between garlic plants and should give you bigger bulbs.
9. Planting Cloves Upside Down
Plant garlic cloves with the pointed end facing up. Planting them upside down will hinder their growth.
Garlic develops roots from its basal plate, which is at the flat end of the clove. The shoot grows from the pointy tip.
If you don’t make sure you plant cloves the right way up, you’ll cause two problems for your garlic.
- The roots will be much higher in the soil than they should be. Because the top layer of soil dries out more quickly than the soil several inches down, the roots will be in a drier zone.
- When the growing shoot emerges, it will grow down a short distance before turning and growing up towards the surface. This means the plant has to waste a lot of energy before it can begin to photosynthesize and may experience stunted growth and produce a smaller head of garlic at harvest time.
If you’ve already planted your garlic, and you think you’ve planted some cloves upside down, don’t worry too much. You’ll still get garlic, even if the heads look a little misshapen.
10. Planting Garlic Too Deep
Garlic is at risk of rotting when it’s planted too deeply in heavier soils that hold more moisture.
An easy way to gauge the planting depth for your garlic is to plant cloves at a depth of 2.5 times their length. If a clove is 1 inch long, you plant it 2.5 inches deep.
11. Not Protecting Garlic From Birds
Birds don’t eat garlic, but they will certainly come and investigate those green shoots as soon as they appear.
They’ll peck up a sprouted garlic clove, realize they don’t want to eat it and drop it on the surface of the soil. Then they’ll grab the next green shoot, and the next, and the next…
To protect your planting bed from birds, use a net stretched over garden hoops.
Once the garlic is 3 or 4 inches tall, the birds won’t bother it anymore and you can remove the net.
I wouldn’t leave the net on any longer than you have to because nets make weeding a nuisance. Instead of taking a few seconds to pluck out the weeds you see as you walk by your garlic bed, you’ve got to remove the net before you can weed.
And because nets are fiddly to work with, it’s tempting to just do it later. Then you forget, and before you know it, the bed is covered with weeds.
12. Planting Too Early In The Fall
Planting garlic too early in the fall can result in frost damage. It’s best to plant garlic about 4 – 6 weeks before the first frost.
When you plant garlic, it establishes its root system before it sends up the growing shoot. The growing shoot won’t emerge if the soil temperature is too low. Instead, your garlic will lie dormant over winter, ready to start growing as soon as winter loses its grip.
But if you plant too early, when the soil is still warm, your garlic plants will send up shoots, and those shoots will have to contend with winter.
Now, if your winters are mild like mine, it’s not much of an issue, but if you have cold winters, that green shoot will struggle. The shoot also acts like a straw, drawing moisture out of the clove and drying it out.
13. Planting Too Late In The Fall
Planting garlic too late can result in smaller bulbs. Make sure you plant your garlic in time for it to establish roots before the ground freezes.
Aim to plant at least 2 weeks before your first frost date.
14. Ignoring Spring Planting
While fall is the best time to plant hardneck garlic, softneck garlic planted in the spring matures quickly and lasts a long time.
If you only plant hardneck garlic, you’ll run out of homegrown garlic because it only stores for 3 to 5 months. Spring-grown garlic (properly cured) will last until your harvest the following year.
Hardneck garlic is ready to harvest first in early summer. Softneck garlic is ready from midsummer to early fall.
By planting both types at the right time, you’ll have plenty of garlic all year round.
15. Not Fertilizing After Planting
Fertilizers come in a variety of formulations. Packages show the ratio of nutrients using a series of 3 letters. N is for nitrogen. P is for phosphorus. K is for potassium.
Garlic benefits from a balanced all-purpose fertilizer at planting time. A fertilizer with a 16-6-4 NPK ratio will boost early garlic growth. Use 1 handful per square yard (use twice as much if you didn’t add compost or manure to your soil).
16. Not Fertilizing During Bulb Growth
During bulb growth, garlic benefits from a fertilizer high in phosphorus and potassium. Avoid using a high-nitrogen fertilizer during this stage or you’ll get lots of leaf growth at the expense of bulb development.
Once the garlic is growing above the soil, use a fertilizer with a 5-10-10 NPK ratio to help your garlic develop large, healthy bulbs.
Bulb growth is triggered by day length. By the time garlic scapes begin to develop in late spring, stop adding nitrogen.
17. Mulching Too Lightly
A light layer of straw or leaf mulch protects garlic from temperature fluctuations, conserves moisture, inhibits weed growth, and feeds the soil as it decomposes.
For a mulch layer to be worthwhile, it should be 2 to 3 inches thick.
Mulches consume nitrogen as they decompose, so make sure you add a nitrogen fertilizer when you plant your garlic.
(Pull back the mulch when you need to fertilize.)
18. Mulching Too Heavily
While mulch is beneficial in a drier climate, it can cause problems in regions that get plenty of rain.
Mulching in a damp environment will lead to overly wet soil and potential disease and rot issues.
Because mulch has important benefits, you won’t want to avoid it altogether. To avoid the risk of rot and disease, make sure the mulch doesn’t touch the growing garlic.
If your garden gets plenty of rain, grow your garlic in a raised bed so the soil can drain easily.
19. Over-Watering
Garlic needs consistent moisture, but over-watering can lead to rot and other diseases.
If your garden gets adequate spring rainfall and you use mulch, you shouldn’t need to water your garlic very often.
But if you’re in a drier region, make sure you water every week to a depth of 1 inch.
Stop watering 2 weeks before your planned harvest date to reduce the risk of disease in your stored bulbs.
20. Forgetting to Snap-Off Scapes
Scapes are the flower stalks that hardneck garlic varieties produce. Snapping them off directs more energy into bulb growth and results in bigger heads of garlic.
If you leave the scapes on, they’ll eventually form a little cluster of garlic cloves right on the stem. You can eat those, or plant them to grow more garlic.
Removing the scapes doesn’t hurt the garlic plants, and gives you an early “garlic crop” to use in salads and stir fry.
21. Harvesting Too Early or Too Late
Harvesting garlic at the right time is crucial for the best yield. If you harvest too early, you’ll get small heads and bulbs that haven’t separated into cloves.
Garlic bulbs double in size during their last month of growth (with the right sunlight and nutrients).
Harvesting too late can result in split bulbs, and the breaking down of the paper covering on the garlic.
So when is the right time to harvest garlic?
If plant leaves are still lush and green, it’s too early.
When the bottom 3 leaves start to droop and have a dry yellowish-brown appearance, lift one or two garlic plants and take a look.
Have the cloves formed? Has the bulb grown its papery skin?
If the answer is yes, your garlic is mature and can be harvested. If the answer is no, let the plants grow a little longer, and check again in another couple of weeks.
Cloves begin to form once day-length reaches 14 hours. Before then, the garlic head will be one single bulb.
Final Thoughts
Despite that long list of garlic-growing mistakes, garlic is one of the easiest crops to grow in your garden. Just make sure you plant the right variety at the right time, in a sunny spot with fertile soil. Keep your plants weed-free and harvest at the right time.
