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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.

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.

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

  1. 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?

  2. 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?

  3. 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.

  4. Judy says:

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

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