My grandmother always planted by the moon. For years I thought it was just an old habit she couldn’t shake. Then I started growing my own vegetables and noticed something odd: her timing often made more sense than the generic advice in gardening books. I don’t check the lunar calendar every morning, but for key decisions – sowing, transplanting, harvesting – I’ve quietly started doing it. Here’s what I’ve learned.
What is a moon calendar for gardening?
A lunar gardening calendar divides days according to the moon’s position into four types:
- Root days: The moon is in an earth sign (Taurus, Virgo, Capricorn). Best for root vegetables: carrots, beetroot, celery, onions, potatoes.
- Flower days: The moon is in an air sign (Gemini, Libra, Aquarius). Best for flowering plants and aromatic herbs.
- Fruit days: The moon is in a fire sign (Aries, Leo, Sagittarius). Best for fruiting vegetables: tomatoes, peppers, cucumbers, courgettes.
- Leaf days: The moon is in a water sign (Cancer, Scorpio, Pisces). Best for leafy vegetables: lettuce, spinach, cabbage.
What does the science actually say?
Honest answer: the scientific evidence is thin but not absent. The Research Institute of Organic Agriculture (FiBL) in Switzerland ran trials over several decades with mixed results. The effects were consistent but modest.
Practical conclusion: If you’re already planning when to sow and harvest, it costs nothing to factor in the lunar calendar.
Practical guide: using the moon calendar in your garden
Sowing
Sow fruiting vegetables (tomatoes, peppers, cucumbers) preferably on fruit days during a waxing moon. Root vegetables on root days. Lettuce and spinach on leaf days. Many lunar gardeners avoid sowing on the day of the full moon and new moon.
Transplanting and pricking out
Root development is supported on root days during a waning moon – the preferred time for repotting and transplanting.
Harvesting
Fruiting vegetables are harvested on fruit days. Herbs for drying are best harvested on flower days during a waxing moon.
Pruning and maintenance
Pruning during a waning moon produces slower, controlled regrowth. Pruning to stimulate growth is done during a waxing moon.
The moon calendar in an app
BioGarden365 doesn’t just show you the current day type – it links it directly to the plants you’ve recorded in your garden plan. If today is a fruit day and you have tomatoes and courgettes, you get a notification telling you what’s beneficial right now. Not a generic message – a recommendation for your garden, your plants, your location.
Common questions about lunar gardening
Do I have to organise everything around the moon? No. It’s enough to check the calendar for important decisions.
What if the right lunar day doesn’t fall at the right time? Garden anyway. The lunar calendar is a tool, not a rulebook.
Which lunar calendar is the right one? The most widely used are the Maria Thun calendar (biodynamic) and the astronomical lunar calendar. BioGarden365 follows the biodynamic method.
Summary
The lunar gardening calendar is not a miracle solution – but it isn’t superstition either. It’s a planning tool that integrates without effort for anyone already gardening in a structured way.