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What To Sow
Planning guide

Sun mapping: how much sun does your garden get?

The single biggest thing that decides what will grow well isn't your soil or your skill — it's light. “Sun mapping” just means working out which parts of your plot are sunny and which are shady, so you can put the right crop in the right place. It takes a day to do and saves you a season of wondering why the tomatoes sulked.

Here's how to read your own plot — and how we use it in the bed planner to place tall crops where they won't shade the rest.

How to sun-map your plot

You don't need an app or a gadget — just a sunny day and three glances out of the window.

  1. Morning (around 9am). Walk the plot and note which beds are in sun and which are still in shadow.
  2. Midday (around 1pm). Do it again. This is the strongest sun of the day.
  3. Late afternoon (around 5pm). Once more. The west side catches this golden, useful light.
  4. Add up the sunny hours for each bed and label it full sun, partial shade or shade (below).
Do it more than once a year
The sun is much higher in June than in March, so a bed that's bright in midsummer can sit in the long shadow of a fence or shed in spring and autumn. If you can, sun-map once in spring and once in summer. Take a quick photo each time — the shadows tell the whole story.

Which way does your garden face?

In the UK the sun is alwayssomewhere in the southern half of the sky — rising in the east, arcing across the south, setting in the west. It never shines from the north. That one fact tells you everything about your plot's “aspect”:

  • South-facing — the jackpot. Sun all day; the warmest, brightest spot. Save it for tomatoes, peppers and anything that needs to ripen.
  • East-facing — morning sun, afternoon shade. Gentle and good for leafy crops; cold on frosty mornings, so go steady with tender plants.
  • West-facing — afternoon and evening sun. Warm and productive; suits most crops.
  • North-facing — the least sun. Fine for leafy salads and shade-tolerant crops, and the right home for a water butt, compost or a seat — but not for ripening fruit.

See how the shadows move

This is the whole reason layout matters. Watch the sun cross from east to west, and see how the tall plant's shadow lengthens and sweeps across the shorter plants beside it — longest in the morning and evening, when the sun sits low.

EmorningS · middayWevening
The sun never crosses the northern sky, so a tall plant's shadow always falls to the north — long in the morning and evening, short at midday. Watch it sweep across the shorter plants: that's why the tall crops belong on the north side.

Full sun, partial shade or shade?

Once you know how many hours each bed gets, match the crop to the light. As a rule: if you eat the fruit, it wants full sun; if you eat the leaves or roots, it'll cope with less.

Full sun

6+ hours direct sun

The hot, bright spots. Anything that fruits or ripens wants to be here.

Grow here: Tomatoes, peppers, chillies, aubergines, courgettes, squash, sweetcorn, beans, most fruit

Partial shade

3–6 hours sun

Sun for part of the day, or dappled light. More forgiving than people think — many crops are happy here, and leaves actually prefer it in high summer.

Grow here: Lettuce & salad leaves, chard, kale & brassicas, peas, beetroot, spinach, most herbs

Shade

Under 3 hours sun

The shady corners. Not much fruits here, but leafy crops will give you something, and it's the place for a water butt, compost or seating rather than a hungry crop.

Grow here: Hardy salad leaves, mint (in a pot), some chard — and not much else

Using it when you plant

  • Tall crops to the north. Put sweetcorn, climbing beans and cordon tomatoes on the north side of a bed so their shadows fall off the bed, not across your shorter crops.
  • Sun-lovers on the sunniest beds. Give your full-sun beds to the crops that need to ripen, and don't waste them on lettuce.
  • Use the shade on purpose. Slip salad and leafy crops into the partly-shaded spots — they bolt less there in a hot summer.
  • Let low crops use the south edge. Keep the sunny front of a bed for the short stuff that would otherwise be overshadowed.
The planner does this for you
In the bed planner you can tell it which way each bed faces, and it draws a compass, a sun marker and a light-to-shade gradient onto your plan — then places the tall crops on the north side automatically, so nothing shades anything it shouldn't.

Common questions

How do I know how much sun my garden gets?

Watch it across a sunny day — morning, midday and late afternoon — and note whether each bed is in sun or shadow each time. Six or more sunny hours is full sun, 3–6 is partial shade, under 3 is shade. Check again later in the year, when the lower sun throws longer shadows.

Which way should a vegetable garden face?

In the UK the sun is always in the southern sky, so a south-facing plot gets the most sun and is ideal. East gives morning sun, west gives afternoon sun, and north-facing gets the least — fine for leaves, not for ripening fruit.

Can you grow vegetables in shade?

Leafy crops (lettuce, chard, kale, spinach), peas and many herbs will crop in partial shade — and bolt less there in high summer. You just can't ripen fruiting crops like tomatoes and squash without full sun.

Plan your beds→Companion planting guide→Crop rotation→Sowing dates for your postcode→