SunnypatchHow much sun does a vegetable garden need?
Most vegetables need at least 6 hours of direct sun a day. Crops grown for their fruit, such as tomatoes and squash, do best with 8 or more. Root crops manage on 4 to 6 hours, and salad leaves and many herbs on 3 to 4.
| Direct sun | Crops |
|---|---|
| 8 hours or more is best; 6 is the least | Tomatoes, peppers, chillies, aubergines (eggplant), squash, pumpkins, courgettes (zucchini), cucumbers, melons, sweetcorn |
| 6 hours or more | Beans, onions, garlic, potatoes, cabbage, broccoli, cauliflower, Brussels sprouts, strawberries |
| 4 to 6 hours | Carrots, beetroot (beets), radishes, turnips, parsnips, leeks, peas |
| 3 to 4 hours | Lettuce, spinach, chard, kale, rocket (arugula), pak choi, parsley, mint, chives, coriander (cilantro) |
A rule that covers most of the table: a crop grown for its fruit or seed needs the most sun, one grown for its root needs less, and one grown for its leaves needs the least.
These are hours of direct sun, with the sun shining straight onto the plants. The guide to full sun and part shade explains what counts.
Choosing the spot for a bed
Count the hours for the whole season, not only midsummer
North of the equator the growing season runs from about April to September. A spot that gets 10 hours in June can get 2 in April, when seedlings go out, because the sun is lower and every shadow is longer. Check the hours in spring as well as in June.
Stay clear of the shadow of anything to the south
At the March equinox, a 1.8 m (6 ft) fence casts a midday shadow about 1.5 m long at the latitude of New York or Madrid, and about 2.3 m long in London. A bed that starts further out than that has the midday sun from March to September. South of the equator, it is the fence to the north that matters. The guide to fence shadow lengths has the figures for other latitudes and heights.
Put tall crops where they don't shade the rest
Sweetcorn, climbing beans and staked tomatoes cast shade of their own. North of the equator, put them at the north end of the bed. Rows that run north to south share the sun most evenly.
Use the shadier end
Lettuce and spinach run to seed in hot sun. In summer they do better with shade in the afternoon, so the end of the bed that a fence shades after lunch is the place for them.
Under 3 hours
Very little will crop well. Grow salad leaves and herbs in pots that can be moved into the sun, or pick another spot.
A worked example
Take a bed in London, 3 m north of a 1.8 m fence, with a 2 m wall 6 m to its west. It gets 14h 15m of direct sun on 21 June and 10h 05m on 20 March, so it is in full sun for the whole growing season. On 21 December it gets none, which matters only for winter crops.
Check your own bed before you dig
Sunnypatch lets you draw the fences and walls around a spot on a satellite map, then shows its hours of direct sun for every day of the year. Drag the pin around the garden to find the sunniest place for the bed. It is free, with no sign-up.