top of page

What Causes Leaf Burn and How to Avoid it

how to avoid leaf burn

Leaf burning is a complex phenomenon and is the result of burst leaf cells. Leaves discolour from grey to brown and feel dry and crunchy to the touch. Other substances from plant material in the vase may also contribute to the leaf burn (leaf necrosis).

leaf burn example

Avoid the following situations to reduce the chance of leaf burn:

  • Exposure to too many hours of daylight or artificial light in winter. The stomata (tiny pores in the leaf surface) lose the ability to close. The flower’s moisture content continues to evaporate and the flower sucks up too much vase water if flower food has been added. However, without flower food the flower often doesn‘t get enough water.

  • Weak tissue resulting from lack of light during the last phase of growth, makes the flower sensitive to flower food.

  • Overdose of flower food from an average of over 150% of the pre-scribed amount.

  • Toxic’ metal ions in the vase water, such as zinc, chlorine, fluoride and iron.

  • Use of vase cleaning products, such as chlorine, washing-up liquid and cleaning or sterilising tablets.

  • Slime or other secretions from other plant material in a mixed bouquet in the container or vase (for example Narcissus slime).

For the best results, we always advise to use clear products, such as RVB Clear Intensive and Professional 2

flowers in vase

How can better hygiene prolong the vase life of flowers?

Decomposing pieces of plant material, dust particles and other pollutants from the air will all contaminate vase water. All this decomposition, organic matter and mould make the water cloudy and dirty and can be a food source for microorganisms. The vascular bundles in the flowers stems, required for absorbing water, can become blocked by this contamination. It is especially evident on the water surface. When the water level drops, the unsightly scum remains on the side of the vase, dries up and becomes visible.

Keeping the vase water clean is the first requirement. The food supplements and acid regulators in Chrysal cut flower foods help flowers to develop in a natural ‘plant-intact way’ and the vase water is not contaminated by all the decomposition products of the stem, as is the case with only tap water. For the best results, always add the right amount of flower food to the indicated amount of water by following the instructions on the back of the pack.  

It is also essential to get into the habit of cleaning containers and vases immediately after use and then again before use, no matter how clean we think they are, as often dust etc. can form whilst being stored. We recommend florists use Chrysal Cleaner for cleaning containers and vases. This is a ‘soft’ cleaning product which isn't for cut flowers. For both florist and consumer it is essential to remove all dirt and contamination by thoroughly cleaning anything you intend to display your flowers in.

Chrysal Logo

With a legacy that spans many decades, Chrysal is a main driving force in the flower and plant industry and worldwide market leader in flower food. Whether you grow, transport, sell, or simply enjoy the beauty of flowers in your own home, Chrysal has a tailor-made solution to keep cut flowers and potted plants looking fresher for longer.




bottom of page