An introduction to moon gardening

05 December 2016

John Harris, head gardener at Tresillian Estate, has been using ancient moon gardening techniques to decide when to plant and harvest at the estate’s highly regarded kitchen garden. Here he explains the basics of understanding lunar gardening.



Dark moon, waxing, quarter-, half-, gibbous, crescent, light, waning… the various names given to the moon phases often cause confusion. The dark (or ‘dark of the’) moon is an old term for the new moon, which is hardly ever visible as it sits between the sun and the earth.

As the moon moves through its first quarter, a waxing crescent (once called the increasing moon) takes us to the point at which we see half the disc, which we call the halfmoon (even though strictly speaking it is only a quarter of the moon).

The waxing gibbous sees us through the second quarter to the full moon, which used to be known as the light moon. (Gibbous, incidentally, means convex or protuberant and when applied to the moon means the illuminated portion when greater than a semicircle, smaller than a circle.)

The full moon is followed by the ‘decreasing moon’, as it was called - waning gibbous as it travels through the third quarter, and on to the fourth quarter, through a waning crescent back to the (dark) new moon – full circle.

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Understanding the moon cycle

The moon month is made up of four quarters over a 29-day cycle, three quarters of seven days, one of eight, changing from month to month. Though various systems give them different names, I’ve just named them first to fourth quarter with new moon at the start and full moon halfway through.

Other versions of moon gardening are more concerned with signs of the zodiac and the positions of the stars. This is a very different approach, not to be confused with the one I’ve developed at Tresillian.

I like to keep an open mind, so I am neither endorsing nor rubbishing other viewpoints. I just follow what works, and I know that the Tresillian version of moon gardening works.

The first day of the first quarter is new moon, when the moon is not visible in the sky. At this point, the strength of the moon’s gravitational pull on Earth is at its weakest.

The pull increases from this low point throughout the first and second quarters. By the end of the second quarter (full moon) and at the start of the third, the gravitational pull is at its strongest.

As soon as the third quarter begins, the strength of the pull begins to fade. It keeps ebbing throughout the third and fourth quarters until you reach the end of the fourth quarter, by which time you’re at new moon again.

Earth’s water table responds to this never-ending rise and fall of gravitational pull. It rises as the moon’s gravitational pull increases and it falls back as it decreases.

When the water table rises it exerts upward pressure. The moisture beneath your garden soil rises with it. This increases the concentration of moisture content at exactly the level in the topsoil where we gardeners do our gardening.

This unfailing act of nature will carry on until the moon stops orbiting Earth. It is of great help to us, especially during periods of low rainfall in the summer, but with careful and aware gardening you can benefit throughout the year. Here’s how...

Moon gardening

The pre-winter dig

If you follow a crop-rotation programme, you’ll be ‘manoeuvring’ and fertilising your soil well in advance of planting out and sowing in the spring. Even if you don’t rotate, this is still worth doing.

The autumn dig begins in September, October or November, preferably October, at the start of the moon’s fourth quarter. The water table has fallen halfway and is still falling. This releases pressure on the dug soil and makes it more receptive to air and airborne higher temperatures.

This combination of ‘drawing in’, warmth and increased airing encourages increased vegetable-processing activity by the soil’s creatures and insects. This sparks a virtuous cycle, which sustains and enhances biological activity, resulting in increased natural fertility.

At this time you need to check your pH and add lime or calcified seaweed to balance the soil. If you find you need to add lime etc., it’s very important to remember that you will then have to wait to apply manure until February.

There needs to be at least two to three months between applications of lime and manure, to allow time for the lime to work its way through the soil. But, if the soil is balanced, you can put the manure in during the dig to help feed this natural activity. At the same time, at the start of the moon’s fourth quarter, the soil, being less moist, is lighter. So it offers less resistance to your fork, spade and hoe.

Find out how to get your soil ready for spring planting

Moon gardening

When to feed

You want to add nutrients to the ground when it’s at its most receptive. This way, you work less, you’re more efficient and your costs are reduced.

Manure and fertilisers should be worked in at the start of the moon’s fourth quarter, as close to the first day as possible. Throughout the third and fourth quarters, the water table is falling, releasing pressure on the dug soil and encouraging more thorough and deeper absorption of any additions to the soil.

Feeds applied during this quarter are drawn into the drier soil and can be applied more sparingly than during other quarters. I wouldn’t be able to afford to run Tresillian or my own garden at home without the help of the moon.

The moon’s final phase sees its pull on Earth diminishing to its lowest point, the water table with it. As the water table recedes it draws any fertiliser applied to a deeper depth and encourages wider, more even dispersal.

Apart from leaving more money in your pocket, using less fertiliser is great for wildlife and the health of the soil generally, reducing chemical build-up – because every drop of run-off adds to the problem, as any farmer will tell you.

Visit our soil improvement section for more information

Moon gardening

When to sow below-ground developing plants

Sow at the start of the moon’s first quarter. Why? For the next two weeks, give or take a day, the moisture content in the soil will be gradually increasing because the water table will be rising.

This will combine with the thoroughly absorbed feeds, which you’ve applied in the previous fourth quarters. This encourages germination of slow developers such as carrots and enhances their survival chances.

Moon gardening

When to sow above-ground developing plants

Above-ground developers such as cabbages tend to be fast growers. Sow these at the start of the moon’s second quarter.

For the following week the well-moistened soil combines with thoroughly absorbed feeds (which you added at the start of the previous fourth quarter). This creates the ideal conditions to encourage the rapid germination that fast developers need both to survive initially and reach their full potential later on.

Moon gardening

When to plant out

One of my golden rules is that feeds should be added to the topsoil ten to fifteen days before sowing or planting out.

This way, your new arrivals get the maximum benefit from the various manures, feeds or fertilisers you add. Planting out can be a traumatic experience for seedlings and young plants generally. Most plants abhor sudden change.

That’s why, unless you handle things carefully, moving plants from a small pot to open ground can mean they don’t take, or they plateau for too long and never reach their full development potential.

For best results, insert young cuttings, plantlets, bushes or saplings into the soil at the start of the moon’s second quarter. Thanks to a rising water table, the soil is already getting moister and will keep doing so for roughly another week. This creates the ideal conditions for supercharging plant development.

A good tip is to plant in the cool at the end of the day. There’s less evaporation, hence greater moisture retention in the soil. The increased pressure on the newly inserted plant’s roots, exerted by the rising water table, encourages increased sap flow and, consequently, faster nutrient ingestion from the soil.

I see this situation as the perfect combination: increased moisture, better nutrient absorption and greater sap flow join forces to create the conditions for excellent, healthy growth. Essentially, all plant life is at its strongest and pushing hard for survival at the end of the second quarter and the beginning of the third. Full moon, in other words.

Moon gardening

When to prune

Wherever practical, all cutting back of plants should be done when the moon is in its fourth quarter, the closer to new moon the better, because you want to minimise sap loss.

Towards the end of the week before new moon, the water table has almost completely fallen and is exerting no upward pressure. This means less sap discharging from the wounds of your surgical operations in the garden, which means faster healing.

I’ve seen apple trees pruned at the wrong time. The inserted cut doesn’t heal and the chances of disease are much greater. In the Tresillian orchards we treat our apple trees like children. You train them intensively when they’re young, but after they’ve reach fourteen or fifteen years you should then have to give these teenagers only the occasional correction via a little light pruning.

A good pruning rule is to aim to keep the centre of your fruit trees open as much as possible to let light in. With older varieties, this is not always possible because of their twiggy, branchy growth. This is the nature of the beast, so one has to accept the fact that this is how they grow. As with particularly wilful children, sometimes it doesn’t matter how much pruning you do, you aren’t going to stop them developing what they initially set out to do.

You need not worry too much, though. A combination of modern grafting techniques and hybridisation means that most varieties you can buy nowadays naturally achieve the optimum ‘open goblet’ effect.

Moon gardening

Harvesting below-ground developed plants to be stored

Remove roots and tubers, such as carrots, from the soil when the moon begins its fourth quarter. At this point the water table is falling towards its lowest level and exerting least upward pressure.

This means the topsoil is in its naturally driest state, and so too are the surfaces of the plants you’re pulling from it. The drier the root or tuber surface, the less likelihood of rot.

For optimum results, harvest at the end of the day, and transfer your produce immediately into store. By doing this, you avoid exposure to the sun and further drying through evaporation. The result is veg staying as firm as when first removed from the soil.

Moon gardening

Harvesting below-ground developed plants to be eaten immediately

Of course, you can’t always wait for those lovely carrots. If you want them for your plate the same evening, the best possible time to pull them from the ground is at full moon, then a few days either side.

The water table’s at its peak, pressure pushing moisture up into the topsoil to its maximum level and, in turn, inducing the maximum amount of sap in your crop. You are pulling veg out of the ground at its juiciest. More moisture = more flavour.

Once again, for the very best results, harvest in the cool of the evening or even at night. This avoids evaporation via exposure to the sun, retains the sap and keeps the flavour packed in.

Moon gardening

Harvesting above-ground developed plants to be stored

Using cabbage as an example, ideally you need to pull leaves, better still the whole plant, from the soil when they’re juiciest and most full of flavour.

This occurs during the first and second quarters, reaching maximum around full moon, when the water table is pushing moisture high up in the topsoil.

In practice, kitchen needs could very well overrule this. Lettuces and cabbages need to plucked when at peak quality and fully mature. There are many variables that will decide maturity, moon phases being only one of them.

Therefore, pull them out when you need them and when they’re mature. If this coincides with a full moon, all the better.

Moon gardening

Harvesting fruit

As with above-ground developers, the priority here is pick when they’re ready – as soon as they’re ripe. Even so, once you start following a moon-gardening calendar, you’ll find that the ripest, sweetest and freshest-tasting fruit is at the end of the second quarter and beginning of the third. The water table’s at its highest, there’s maximum pressure on the tree’s roots, and the sap’s flowing fullest – all combining to increase flavour.

For all harvesting, it’s best to pick fruit in the cool of the evening. This avoids evaporation and ensures your fruit will be in tiptop condition.

Moon Gardening by John Harris is available now, published by John Blake books, RRP £12.99.

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.