Gardening tips for October 2026

Now we are into the autumn months, have you ever wondered why plants can have different coloured leaves? Not the complete rainbow, but yellow, orange, red and purple are common alternatives to the various hues of green. But aren’t they all really green? Yes – but bear with! 

Chlorophyll is the most recognisable plant-based compound responsible for photosynthesis. Other compounds such as carotenoids and anthocyanins absorb different wavelengths of light, which results in the diverse colours we see, especially as seasons change and chlorophyll levels decrease. Chlorophyl absorbs blue and red light from sunlight reflecting green so we see green leaves.

Key Pigments

Pigment	Colour Range	Function
Chlorophyll	Green	Essential for photosynthesis; absorbs light energy
Carotenoids	Yellow to Orange	Absorbs light energy and protects against excess light
Anthocyanins	Red to Purple	May protect against UV light and attract pollinators

Why some plants have coloured leaves is not fully understood, but it is known that anthocyanin is responsible for giving us red looking leaves, also the red colour of grapes, onions, blueberries and the blue cornflowers. Some trees have very high levels of anthocyanin such as copper beach, but why bother if green leaves are all that is needed?

Plants often use the red pigment as a sunscreen. Plant seedlings and the fresh sensitive foliage of many plants are often reddish in colour, begonias are a good example. Until the young leaves are strong enough, the red pigment protects them from sun damage. The copper beech however retains its sun protection for most of the summer because it lacks an enzyme that normally breaks down the red pigment in young leaves. As a result, the foliage of the copper beech remains red throughout the summer. The red colour of leaves is also a defence against predators, aiming to fool them into thinking the plant is inedible. The leaves remain red providing there is sufficient sunlight.  Many red leaf trees will have a greener side due to lower light where the tree increases the level of chlorophyll to compensate.

Carotenoids are yellow and orange (sometimes red) pigments produced by all photosynthetic plants and are primarily used as accessory pigments to chlorophyll and play an important role in protecting leaves from free radical damage. Carotenoids give their characteristic colour to carrots, parsnips, tomatoes and daffodils as well as to flamingos, salmon, lobster and shrimp, so it is not just plants that benefit from colouration. There are over 1000 different carotenoids used in nature, about 50 of which are an important and integral part of the human diet and function. Some carotenoids contain macular pigments which are essential to visual function so make sure you keep eating your fruit and veg.

Carotenoids are most noticeable during the autumn. As chlorophyll in the leaves start sto get broken down, the colours of the various carotenoids becomes obvious in the colours we see as autumn colour.

Lawns

I mentioned last year that lawns took a hammering due to the hot summer, but it is nothing compared to this year’s fry-up. So, a quick update following last month’s advice to leave the lawns alone to recover from the summer. September rain has started to bring colour back but don’t rush into normal grass care activities just yet. Give it time and only cut lightly if needed and leave a good 40mm of grass over the winter months. I still suggest weeding, feeding and scarifying should be left for this year and start normal lawn care in the spring.

Keep gardening, Richard Haigh