I plant on 30" wide beds into which I plant double rows spaced 1 ft apart with two plants/ft in the row. Mulched with wood chips on top of the bed and hay on the bed shoulders. Good production.

see link below foran experiment which showed 6" in-row spacing yielded best.

Here is a link that might be useful: CSU experiment with in-row spacing

In a catalog I respect, the recommend rows across a 32 foot bed. 5 inches between plants, 9 inches between rows.

I have raised beds that are 3 - 4 feet wide.
I start 4-5 inches in from the side, and I plant 6 inch spacing in all directions.
Elephant garlic I go to 7-8 inches.
For sSome of the varieties that have fuller and more vigorous plants, I am going to plant at 7-8 inch spacing.

I mulch with an inch or so of course straw, covered by an inch or so of chopped straw, chopped leaf, grass clippings combo. Basically, I bust a bale of straw in the lawn, and mow it with the grass and whatever leaves are there. Knowing this 3 inch layer will compress in the rain, I do plant my garlic (or at least I try to) about one inch less deep in the soil, than I am supposed to.

The key, I believe, is plant spacing, not row spacing.

Let's say you normally plant at 5-inch spacing. There is no reason you can not just plant the entire bed on 5-inch centers. With a 30 inch row, there would be no problem reaching across if you had to.

I know many people who use a panel of lattice to control spacing. They lay it down on the amended soil and plant once clove in each opening. The lattice remains in place to act as a mulch.

That said, my own system is to run double rows, 8" apart, seperated by 2 foot paths. The paths are used both to get around the overall alliums patch, and to grow other veggies, primarily in containers. I used to use 4" plant spacing (which is the generally recommended amount). However, based on both my own experiences, and discussions with Martin, I've gone to six inches, and that seems to make the plants happier.

Curious thing Nelz-is that the study done in the post above yours used hand or flame weeding with no mention of mulch of any kind except for the early row cover.I bet if the study had included straw/leaf mulch things would have been a bit different.Whats your take on this?
Bill

Bill, in that Colorado test, did you also notice that there was no difference in bulb size if scapes were removed or left? I've yet to notice a difference myself!

As for spacing, 6" is a good generic recommendation. However, that would be assuming that one size fits all. With the mix that I've grown the past few years, I'm certain that several would be happy with 4". On the other hand, there are a few where 8" may be crowding them. I'm going to try to remember that when I plant everything back this fall. The little Wildfire, Legacy, and Pennsylvania Dutch will be crowded at 4" while Music and Northern Giant will get 8". Everything else will get a minimum of 6".

Martin

That was an interesting study. When I first read your post Bill, I thought you were goofing on possibly flame weeding a straw/leaf mulched bed. But then I realized you weren't.

aside: 5 years ago I go out in the garden and one of my straw covered paths looks awfully black for about 8-10 feeet. Plants seem fine. My wife comes home and I forget to ask her, but later she mentions she was burning some boxes (campfire pit about 15 feet from garden) and looks up to see tiny flames and smoldering straw working it's way down the path. She went over and stomped it out, then hosed it down. Luckily I had watered that morning.

Back to the topic at hand.

From the study it appears that 6 inch spacing, snapping off of scapes, and giving plenty of water increases yield, as measured by bulb size.

I think the weeding part of the study was a waste of time. Do I flame them once, or hand pick them. A better study would have been weeding versus not, or mulching versus not, or comparing different mulches.

My speculation would be that a well mulched bed would show an increase in bulb size, over a non mulched bed, for the following reasons:

1 - More even moisture level in bed, means a steadier supply for the plant. Using this as proof might be quite a stretch from the 1 vs 2 drip line system, but it does show that more water seems to yield bigger bulbs.

2 - A mulched bed presents far less weed competition for the garlic. A few years ago I somehow missed a chunk of one bed when mulching, and the weeds were hideous the following spring, and I never quite overcame them (found a rabbits nest in there, with 6 babies no less, when picking). The bulbs in that area were very, very small. I traded them as 'junk bulbs' to a guy who wanted 5 pounds of any garlic. He boiled the skins off and used it in canning. In return I got several bottles of some very good homemade wine!

I know I'm quite happy with 6 inch spacing, and hand watering and weeding a well mulch bed.

They also mentioned time saving & cost with the flameing.
I would also think that mulching might even cut the costs further,with the 1 time mulch and it breaking down to add organic fert.along with aiding/rebuilding the soil.
Bill

A couple of comments on the study and its applicability to home gardeners.

First, while not spelled out, my impression is that they used all the cloves from the sample heads. But, because we tend to choose the largest cloves for replanting, it's likely that we would get a higher percentage of large and extra large bulbs, all else being equal.

Next, and more crucial; the study is aimed at commercial growers. There is no way most of us can economically use flame weeding, considing both the initial capital cost and the operating costs.

The graphs seem to contradict the text conclusions. There is, variously, a 10-15% greater size yield in the plants without scapes, according to the charts. Given the small size of the samples, I would call that statistically significant, and there's obviously need for more study.

Doesn't sound right that they would use all cloves from each bulb Gardenlad.I was just to a variety selling site and they mention they sell all unused cloves(probably the smaller 1s) that are left over after planting.
Whats your take on using all the cloves from 1 bulb when planting back?
Would you not think there would many be different sized and probably much smaller or rounds from any of the small cloves that were planted?
BIll

I have a related question (or perhaps it's the same question) to Bill's. My husband contends that since each clove is genetically the same within each head, then a small clove from a large head will produce consistently a larger head than a large clove from a small head. Seems like I read that in the "Growing Great Garlic" book also--go for the seed of a large head over large seed from a small head. What are your thoughts on this?

Bill, I think we're starting to mix apples and oranges.

Don't confuse what a university study does with how a commercial grower or seed supplier does things. They can be two different things.

My thinking, re: the study, is that by planting all the cloves they are eliminating one variable. If you plant _all_ the cloves, you wind up with a level playing field, so far as statistical comparison is concerned.

Personally, I'd be concerned about the quality of any seller that offered individual cloves instead of whole bulbs.

Ali Yum: Maybe so. But keep in mind, too, that there is a normal genetic variation in everything. That's why, for instance, you have color and pattern variations in a bean that is growing true to type.

But also consider this. Cloves are not the same as seed. Every clove within a variety is a clone. That being the case, in theory it shouldn't matter at all: every clove should reproduce as a twin given the same growing conditions. But we know that doesn't happen.

All of which merely proves that we have a lot to learn, yet, about allium genetics.

What I do, each season, is simply plant the largest cloves I have available. After curing, I pick out the largest heads, and temporarily reserve them as seed stock. When I'm ready to plant I pop the largest cloves on those and use them as seed. The rest goes into my kitchen supply for more or less immediate use.

Your probably correct gardenlad but now LOL what about the bulbils??Any chance of genetic diversity or can they also be considered clones as they do somewhat mature as bulbils if you will and are attached to the plant not as seed as we know it but as a first year set of a biennial type plant.
Bill