According to almanac tradition, brussels sprouts count as a leaf crop. Gardeners who plant by the Moon set leaf crops in the first quarter, from new moon to first quarter, on days when the Moon sits in a fruitful or semi-fruitful sign. For 2027, that gives June 6-7 (Moon in Cancer), July 4 (Moon in Cancer) and July 9-10 (Moon in Libra). No effect of the Moon on this crop has been proven.
What the tradition says about planting brussels sprouts
The quarter rule
The almanac rule is simple to state. Crops are sorted by what part of the plant people use, and each type gets a quarter of the lunar cycle. Brussels sprouts fall under “leaf,” the group that holds leafy crops and crops whose seed is outside the fruit. Almanacs list lettuce, spinach, cabbage, broccoli and celery in that group, and brussels sprouts sit in the same family of crops. Tradition assigns the whole group to the first quarter. That is the stretch from new moon to first quarter, when the Moon is waxing and the lit part is still growing toward half.
| Crop type | Traditional quarter | Examples in the almanac list |
|---|---|---|
| Leaf (brussels sprouts) | First quarter: new moon to first quarter | Lettuce, spinach, cabbage, broccoli, celery |
| Fruit (seed inside the fruit) | Second quarter: first quarter to full moon | Tomatoes, peppers, beans, squash, corn |
| Root, bulb, perennial | Third quarter: full moon to last quarter | Potatoes, carrots, garlic, onions, beets |
The fourth quarter, from last quarter to new moon, is set aside in the same tradition for rest: weeding, pruning, turning the soil and composting. Some almanacs add a second filter, the Moon’s zodiac sign. This convention labels Cancer, Scorpio and Pisces fruitful, and Taurus, Libra and Capricorn semi-fruitful. The days later on this page use both filters. More background on the whole custom is in our guide to planting by the moon.
What is and is not proven
No effect of the Moon’s phase or sign on brussels sprouts, or on any other crop, is established. The one measurable thing the Moon does at Earth’s surface is tidal pull, and NASA’s published constants (Moon Fact Sheet) let us put a number on it. At its strongest, that pull comes to about 1.1 millionths of a meter per second squared, roughly one ten-millionth of gravity. That is far too small to move anything as light as a seed or a root.
So treat everything below as a custom with a long history, not a mechanism. Gardeners follow it for habit, for the pleasure of a schedule, or to run their own comparison. Those are fair reasons. A promised result is not one.
Traditional brussels sprouts planting days, 2026 and 2027
The days, with the Moon sign
Each row below combines the first-quarter rule with a fruitful or semi-fruitful Moon sign. Only months that carry such days appear.
| Month | Traditional days | Moon sign |
|---|---|---|
| June 2027 | June 6-7 | Cancer |
| July 2027 | July 4 July 9-10 |
Cancer Libra |
The months shown are those when gardeners in much of the country plant brussels sprouts, but your state may start earlier or later. Only the rows that fall inside your own state’s window count. If none do, the table simply does not apply to your garden.
Days are read at noon Eastern time, and the Moon changes sign during the day. Treat the first and last day of each run as soft edges, since the sign may switch in the morning or the evening. A gardener on the West Coast, where noon falls three hours later, may find a day’s sign differs from the table for part of that day.
How the sign labels fit in
Cancer carries the “fruitful” label in the convention described above, which is why the Cancer days make the list. Libra is labeled semi-fruitful, so the July 9-10 run is a weaker entry in the same system. Sources differ on a few other signs (Virgo, Sagittarius and Aquarius), but none of those matter for the rows here.
A second system gives a different reading. Maria Thun’s biodynamic calendar sorts days into root, flower, leaf and fruit types by sign. In that scheme Cancer, Scorpio and Pisces are leaf days, which lines up with brussels sprouts, while Libra is a flower day. A gardener who follows Thun alone would keep the Cancer days and drop the Libra run. That is a reminder these are conventions, not measurements, and two almanacs can disagree about the same afternoon.
One more detail explains why the list is short. The phase cycle takes 29.53 days, while the Moon’s trip around the sky against the stars takes 27.32 days. Because the two cycles run at different lengths, a given sign lands in a different phase each month, and only some months line up a first-quarter Moon with a favorable sign.
Check your state first: when to plant brussels sprouts where you live
The order of decisions matters more than the Moon does. First comes your state’s planting calendar for brussels sprouts. Only after that, if you want to use the custom, does the Moon enter. Frost dates and soil temperature decide whether a crop can go in the ground. The Moon, for anyone who follows it, only chooses among days that your local calendar has already opened.
Our page on when to plant brussels sprouts where you live covers the calendar side: planting windows, soil temperatures and frost timing. Those numbers live there so they can be kept accurate for each region, and they are deliberately not repeated here. Our state guides go further and set out what each state’s growing season allows.
A practical sequence looks like this:
- Find your state’s brussels sprouts window on the linked pages and note its first and last dates.
- Look at the table above and keep only the rows that fall inside that window.
- If a traditional day fits, plan around it. If none fits, plant on the date your state calendar supports.
- Skip the Moon entirely if you prefer. Nothing in the state calendar depends on it.
Brussels sprouts planted on a traditional day outside your window are no more likely to do well, and the calendar of your place takes precedence every time. Gardeners who plant by the Moon tend to treat it as a tiebreaker. If two or three dates in a week are all open on the state calendar, they pick the one the almanac marks. That is the whole role the Moon plays here, and it is a modest one.
A fair way to try it
Gardeners who plant by the Moon usually say it has worked for them. That is a claim, not a result, and there is a way to check it on your own plot without much effort. It takes some bookkeeping more than any special skill.
- Pick one week that is open on your state’s calendar and contains a traditional day from the table. Split your planting in two, half on the traditional day and half on an ordinary day inside the same week.
- Treat both halves the same way: same variety, same seed or transplant source, same bed conditions, same watering. Label each half with a stake or tag that names the date and the group.
- Record when seedlings or transplants first show growth in each group, how many survive, and the dates and weights of your harvest.
- Compare the notes at the end of the season, and keep them for next year.
One season will not settle anything. Weather, pests and small differences in the soil can swamp a gap between two halves of a bed, and a gap in either direction could be chance. Several seasons of notes would start to say something, though even then they speak only for your own plot. For a home gardener, side-by-side planting is the only way to judge the custom for yourself, and it may turn out you see no difference at all. That is a perfectly useful answer.
Questions about planting brussels sprouts by the moon
Does the tradition say to plant brussels sprouts in a waxing or a waning moon?
Waxing. Leaf crops go in the first quarter, which runs from new moon to first quarter, and that is part of the waxing Moon. The next stretch, from first quarter to full moon, is also waxing but is assigned to fruit crops in the same system. Waning quarters are given to roots and rest. If you want to read more about the waxing half of the cycle, see our page on planting in a waxing moon.
What if the traditional day falls on a frost?
Let the day go. The almanac tradition is about picking among days, not about overriding a place’s weather, and your state’s calendar and local conditions decide whether planting is open at all. Wait for the next traditional day, or plant on an ordinary day that your state calendar supports. The state pages linked above cover frost timing for your area.
Do I need to follow the Moon sign as well?
Not necessarily. Gardeners who plant by phase alone use the whole first quarter and ignore the sign, which gives many more days. Moon-sign almanacs add the fruitful and semi-fruitful labels, and that narrowing produced the short list in the table. Maria Thun’s calendar goes the other way and uses the sign alone, ignoring the phase, with Cancer, Scorpio and Pisces as leaf days. You can follow any of the three, or none, and the choice is yours.