Ascending or descending moon for planting potatoes?

Tradition is unanimous: descending moon, on a root day, the sap being said to sit at soil level. In practice, the deciding factor is temperature: soil at eight or ten degrees, otherwise the tubers wait in the cold and risk rotting.

Can I follow the lunar calendar if the soil is still cold?

The calendar marks windows, not obligations. If the soil clings to the spade or stays icy, let the window pass: there’ll be another at the next lunation. The moon has never warmed a soil.

In the garden · March

Gardening by the moon in March March

March reopens the garden. Lunar tradition unfolds its two phases: in the ascending moon, the first outdoor sowings (carrots, radishes, spinach, peas) and the warm-started sowings that carry on; in the descending moon, planting early potatoes, onions and shallots, and pruning the roses. The soil warms more slowly than the air: it’s the soil you must listen to.

The essentials

To sow: outdoors: carrots, radishes, spinach, peas; in the warm: tomatoes, basil
To prune, to plant: roses, summer-flowering shrubs; early potatoes, onions, shallots
To harvest: last leeks, winter spinach, first lettuces under cover
Watchword: be bold, in stages

The March kitchen garden by lunar tradition

The ascending moon, where the sap is said to reach the upper parts of the plant, becomes a real program again: the first outdoor sowings are worth a try as soon as the soil crumbles without sticking. Carrots, radishes, spinach and peas open the season; indoors, tomatoes and basil go on germinating in the warm. Tradition also places grafting in the ascending moon, and March is its great month.

During the descending moon, attention turns to the soil: tradition plants early potatoes in mild climates, onions and shallots, and prunes the roses along with the shrubs that will flower in summer. With the sap flowing back toward the roots, it’s also the good window to prick out what has germinated under cover.

Carrots, potatoes, roses: the crops of the month

In the traditional grid of days, every crop follows the part you harvest from it: carrots and radishes on root days, spinach and lettuces on leaf days, peas on fruit days, since it’s their seed we eat. No need to make a religion of it: remember the correspondence, and the calendar sorts the dates for you.

The potato carries the folklore of the month: planted in the descending moon, on a root day, in warmed soil. Tradition says it makes more tubers and less foliage that way. The roses, for their part, are pruned in the descending moon: the plant is said to heal better when the sap sits low.

The gesture of the month: waking the soil without turning it

Choose a bed, remove the winter mulch, and aerate the soil with a broadfork or a simple cultivator, without turning it: the worms and fungi that give it structure each live on their own level, and deep digging mixes them up for nothing. A few crossing passes are enough for water and air to circulate again.

In a pot the same gesture works in miniature: scratch the surface, remove a couple of centimeters of old compost and replace them with ripe compost. Your balcony containers will set off like a fresh garden bed.

What the trials say

Trials at agronomic research stations found no reproducible difference between crops grown “with” or “without” the moon. What the calendar really brings is a tempo: it spaces out the jobs of March and teaches you to look at your soil before your diary.

The lunations of March (exact dates)

Calculated from the ephemeris, in London time, and rechecked every night. Each lunation has its own detailed page.

Frequently asked questions

Ascending or descending moon for planting potatoes?: Tradition is unanimous: descending moon, on a root day, the sap being said to sit at soil level. In practice, the deciding factor is temperature: soil at eight or ten degrees, otherwise the tubers wait in the cold and risk rotting.
Can I follow the lunar calendar if the soil is still cold?: The calendar marks windows, not obligations. If the soil clings to the spade or stays icy, let the window pass: there’ll be another at the next lunation. The moon has never warmed a soil.