Beginning Farmer Asks: I had a quick question for you regarding plant spacing on cauliflower. I have read some material that suggests row spacing anywhere from 12-24 inches. It is looking like I will be planting into 60-inch beds, so I am curious what you think the proper spacing should be. I would really like to plant a double row 60s.
Farmer Mentor Answers: On a 60 inch bed you can definitely have the plant lines spaced @ 30 inches which would probably be optimal. Then you simply need to decide what plant population per acre you are after.
With plant lines @ 30 inches a 12 inch spacing between plants would give you a plant population of 17,424 plants per acre.
@ 8 inches between plants you would have 26,134 plants per acre
@ 10 inches between plants you would have 20,908 plants per acre
These “plants per acre” spacings can be calculated by dividing 43,560 (Square feet per acre) by the product of the between-row and in-the-row-spacings (expressed as feet).
If it was me I would be shooting for between 20 and 25 thousand plants per acre for optimum yield and good size. So much will depend on variety, fertility and water.
In the ideal world you would plant on single 30-inch rows. Irrigation could be either with drip or overhead. Don't know if you have access to overhead. This configuration - assuming you had the proper cultivation implements - would allow for good weed management. The best cultivator for this spacing would be a two-row lilliston cultivator running the "four spider" gangs. With this set up and good timing on the cultivations you could do a pretty good job of weed management - especially since you can count on a super high weed seed count. Your best bet would be to do a pre-irrigation on the field to get a good weed flush, then knock out the weeds with the lilliston cultivator then plant the cauliflower then do one or two follow up cultivations.
If you don't have access to a good two-row lilliston then the 60-inch beds would be your second best option. You could cultivate with sweeps and knives but you will be dealing with tremendous weed pressure between plants. The beauty of the single line system is that you can form the beds, mark the bed middles by creating a little "V" in the bed middle, plant and lay drip in the "V", then when the weeds emerge you can go through with the lilliston and lightly tilth the bed sides while carefully pushing dirt toward the plant. When done well this procedure can very effectively smother the small newly germinated weeds in the plant line, cover the drip with soil and brace the plants as well. This takes a significant amount of experience but will save hundreds of hours of hand weeding.
If you’re interested to learn more about row spacing considerations, visit