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Planting garlic – When Is The Right Time?

The recommended time for planting garlic in colder climates is mid-fall – October in zone 5. That certainly works but is that the best time?

Spring bulbs, like tulips, are also planted in fall but common advice for these is to plant them as soon as you get them. Earlier is certainly better than later. Planting earlier allows the bulb more time to develop a good root system before winter sets in. Since garlic is a bulb, would the same logic not apply to it? Would it not be better to plant garlic sooner?

Planting garlic - When Is The Right Time? From left to right, Aug 2, Sept 1, Oct 1, by Robert Pavlis

Planting garlic – When Is The Right Time? From left to right, Aug 2, Sept 1, Oct 1, by Robert Pavlis

Planting Garlic

Garlic is grown by planting a clove of garlic, which is a bulb. After planting, the clove makes roots while the soil is still warm, and it may also start growing some green leaves which poke out from the soil.

Spring bulbs do exactly the same thing. As temperatures drop in late summer or early fall, they start to make roots. This is then followed by leaves. The leaves will grow until they are just below the surface of the soil and then they stop growing until spring. The first time I heard this I didn’t believe it, so I went out in fall and started digging around and sure enough almost every one of the bulbs had leaves just below the surface.

In hindsight, this makes perfect sense. By growing leaves in fall the plant gets a head start on spring and can flower earlier.

Since garlic has the same growth habit it only makes sense that planting garlic earlier should work. In fact it might even make larger plants since they get an earlier start. An earlier start should produce larger bulbs at harvest time? All this logic seems to make sense, but I found no information to support it.

Most home gardeners, and most commercial growers plant late fall once temperatures are already quite low.

This is the perfect scenario for a little experiment.

Really Early Planting

What happens if you plant real early? As I was planting my garlic, I found some smaller bulbs that had been in the garlic roots in Septemberground for at least a full year and maybe two. They are the result of letting one plant go to seed, which produces baby garlic bulbs. These fell to the ground and I just ignored them – until now.

I dug them at the end of September. You can see that they are already producing both green shoots and lots of roots. It certainly seems as if early planting would be a benefit to garlic.

Testing Garlic Planting Dates

I have grown garlic in the same bed for a number of years and they always produce a great crop with very large cloves. I am in zone 5 and grow hardneck garlic. I know from past experience that the whole bed produces about the same size garlic.

In fall of 2016, I made three different plantings on Aug 2, Sept 1 and Oct 1.

Planting depth and spacing (4-5″) were the same for all bulbs. The bed was mulched with 3″ of wood chips after planting. Urea fertilizer was added the following spring. The beds were watered as needed to keep the soil moist. I find that the combination of clay soil, rain and mulch are enough to keep the soil moist most of the time.

To keep my observations as objective as possible, the markers with planting dates were buried so that I did not know when specific plants were planted.

Garlic Growth in Spring

The August 2 planting was the first to show new growth in spring but within a week green tips were found for all planting dates. There seemed to be very little difference between the dates.

When the plants were about a foot tall, all of the plants seemed to be the same height. Looking at the plants you could not tell which were planted early.

Plant Size at Harvest Time

Plants were harvested the last week of July. At that time all plants were the same height.

Planting time for garlic did not affect plant height, by Robert Pavlis

Planting time for garlic did not affect plant height, by Robert Pavlis

Bulb Size and Number of Cloves

You can see from the top picture that the size of the cloves were the same for each planting date.

The clove count is important to me. Large cloves mean less peeling, which makes them easier to use. The number of cloves per bulb were: 4.25 (Aug 2), 4.4 (Sept 1) and 4 (Oct 1). No significant difference.

Best time to Plant Garlic

In this test, planting any time from August 1 to October 1 produced the same results. Contrary to popular belief there was no benefit to planting late.

Why do people advise late planting? It could be the repetition of historical advice which has no basis. It is possible that farmers are just too busy earlier in fall and that October is more convenient for them. Gardeners then follow this advice.

Some have suggested that planting earlier may give pests and diseases more time to attack the garlic, but where is the evidence that this is true?

Keep in mind that this test looked at one unnamed variety of hardneck garlic. Other varieties of hardneck or softneck garlic may behave differently. I also tested only one type of soil – mine – about 40% clay. Different soils may give different results.

How Late Can You Plant Garlic?

That is a good question. I now wish I had tried some later dates. I also see people asking about planting in  spring, mostly because they forgot to do it in fall. It sounds like another experiment to try for next year.

If you grow garlic, try different planting times and post your results in the comments below. Include information about the type of garlic and your planting zone.

More Information About Growing Garlic

Article on Growing garlic

Which is better, hardneck or softneck?

Video on growing garlic:

 

If the above video does not play, try: https://youtu.be/NuCqoGZEcks

Garlic nematodes – the above video includes a segment about garlic nematodes at the 2:40 minute mark.

 

Robert Pavlis
Editor of GardenMyths.com
I live in southern Ontario, Canada, zone 5 and have been gardening a long time. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

I hope you find Garden Myths an educational site that helps you understand your garden better.

19 Responses to 'Planting garlic – When Is The Right Time?'

  1. I’ve wondered about this as well – thanks for starting to experiment and publishing your results. One impulse I’ve resisted so far is to simply replant the garlic as I harvest – I’m there in the bed digging around already! I may try this next year.
    Another reason for later planting for me is that I usually do switch around where I grow the garlic. Often there are summer or even fall crops in the way earlier.

    • This year I left some smaller garlic bulbs in the garden at harvest time. I replanted my garlic a few days ago and dug up these bulbs. They looked fine, and had roots on them that were already several inches long.

  2. Josh says:

    I’m thinking of growing garlic in a living mulch. To do this I’d simultaneously sow garlic and vetch in pre-prepared beds sometime in August. Vetch is good at suppressing weeds, so I’m wondering whether the garlic will make it through the vetch in the spring?

  3. Andy says:

    I planted 6 batches of garlic at different times, not because I was being clever or testing but because I started planting some and ran out of space and had to prepare more beds. Then I got bored or couldn’t be bothered to do the rest for a while. The end result was 6 different planting times from October,November, December, January, March and April. I don’t know the dates just the month. 3 Different garlics. All the ones planted from October to January reached a good size, and were what I call good. March planted garlic was variable in size with most OK and April garlics were more small and not worth having with the odd few that were OK.

    I did the same for onions. Only the onions planted in Oct to January could I call good, later ones were so variable I won’t bother doing late next time. Some of the late plantings were good, very usable, but most were not. Simply too small.

    I will be planting all garlic and onions around Oct to Jan this year depending when I can be bothered or have time. After that I won’t wast my time planting any left over because there are more reliable things that the space could be used for.

    All I’ve read is that garlic want a cold spell, after that they simply need enough time to grow.

    Good post, Robert…as always!

  4. skyeent says:

    I have heard that planting the garlic in spring or autumn may be to do with either the size or number of bulbils. I think that if you plant in spring you are more likely to get one larger bulb rather than several bulbils (actually that might be useful!). But since I can’t give a source and can’t remembr trying this myself, an experiment is still in order!

  5. Dr. Linda Gilkeson, a vegetable gardening expert here in coastal BC, says this in her monthly gardening message from October 2016:

    “I learned that to avoid Blue Mold Rot (Penicillium spp.), it is best to plant later in the fall, rather than earlier. This is one of the most common fungus diseases of stored garlic and onions. It overwinters on infected cloves, not in the soil, and it infects in warm 22-25oC (72-77oF), dry conditions.

    If you plant healthy garlic cloves (inspect each carefully for signs of the characteristic blue-green mold) and plant after the soil has become cold and wet (later October) there is little likelihood of infection. Apparently all you procrastinating gardeners have been doing yourselves a favour….”

    http://www.lindagilkeson.ca/gardening-pdf/Fall%20Gardening%20-%20Oct%201%202016.pdf

    • Thanks for posting this. I have been doing some research on when to plant spring bulbs and with Tulips, a later plating is recommended because it lessons the chance of disease. earlier planting does produce better roots, but that needs to be balanced with less disease.

      I will look into garlic and disease more, but I would not be surprised if later planting is better for controlling disease. This is really a function of soil temperature, and the October recommendation would not apply everywhere.

  6. Bonnie says:

    You did say that other bulbs like tulips should be planted as soon as they’re available. I really disagree with that. From years of experience, as well as talking with bulb growers–both in Holland and here (including Brent Heath at Brent and Becky’s Bulbs), most fall planted bulbs should go in when soil temps are below 60. That puts it mid-October to November here in central Virginia. Since most bulbs arrive in the stores around Labor Day, we don’t want to plant them asap. The exceptions for me would be bulbs like lilies or fritillaria would do not have a protective “tunic”.

    • That is a common thought, but it is not true. Consider that last years bulbs are already in the ground and they do just fine. If it was important to plant late, you would need to dig up your bulbs each year and replant.

      But if you have a reference showing that late planting is an advantage – I’d like to see it.

      • Bonnie says:

        In Brent Heath’s book “Tulips for North American Gardens” Brent says, “Generally speaking, planting should not occur until the soil temperature in your area is 60 degrees or less at 6-12″ deep. this is usually after the first heavy frost, but three or four weeks before the soil freezes solid. A bulb may be stressed if planted in soil that is too warm and damp.” I figure I’m not going to argue with someone who actually makes their living growing bulbs…

        • Is Brent basing his comment on actual science, or on historical myths?

          What about the bulbs from last year? They sit in warm soil all summer long and don’t seem to be harmed? Why are they different from the ones you just bought? If they are not different, then why does Brent not recommend digging up the bulbs each year?

          • Andy says:

            would this be comparable tho – a last year bulb in ground might have active roots throughout the summer that continues to work and a dug bulb is “inactive” thus a new planting during earlier season might make it vulnerable? just a thought, never proven.

          • Depends on the bulb. Things like tulips do not have active roots in summer – no need since there is no top growth. Garlic is actively growing in summer and has active roots.

  7. Josh says:

    Great experiment Robert! Thank you. I have two myth related questions:

    1) I have read that you don’t need to rotate garlic (or alliums in general) and that they get better the longer you grow them in one spot. Myth?

    2) I have also read that slugs do not eat alliums such as garlic, however a gardener friend of mine swore that the slugs ate his. What is your experience?

    • I doubt that growing the same crop in one spot makes it better. I do that because I have a small vegetable garden, and they can sit outside the fence because deer leave them alone. However, in a small garden crop rotation is useless so it does not really matter.

      Nothing bothers my alliums, but I don’t have a lot of slug problems.

  8. Judy says:

    I wish you lived in Zone 11; I’m in tropical Australia – right up the top!!

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