Foliar feeding facts for kids

Foliar feeding is a special way to give plants food. Instead of adding fertilizer to the soil, you spray a liquid fertilizer directly onto the leaves of the plant. Plants are amazing because they can soak up important nutrients through their leaves!

They do this through tiny pores called stomata (like little mouths on the leaves) and also through their outer skin, called the epidermis. Nutrients usually get in faster through the stomata, but the epidermis can absorb a lot too. Even the bark of some plants can take in nutrients!

Years ago, some people thought foliar feeding might hurt plants like tomatoes. But now, it's a common and helpful method used by many gardeners and farmers.

Why Use Ocean Plants for Feeding?

One popular way to do foliar feeding is by using mixes made from plants that grow in the ocean, especially kelp. Kelp is a type of seaweed that is packed with many different "trace nutrients." These are tiny amounts of elements that plants need to grow healthy and strong.

It can be tricky to make sure soil has the right balance of all these tiny nutrients. But kelp naturally contains many of them. Kelp also has natural plant hormones. These hormones are great for helping plants grow their leaves, flowers, and fruit. This makes kelp a favorite choice for organic gardeners who prefer natural solutions over man-made chemicals.

How We Know Foliar Feeding Works

In the 1950s, two scientists named H. B. Tukey and S. H. Wittwer at Michigan State University (MSU) proved that foliar feeding really works. They used a clever method: they put special radioactive versions of phosphorus and potassium onto plant leaves.

Then, they used a Geiger counter (a device that detects radiation) to watch how the plants absorbed these nutrients. They found that the nutrients moved quickly through the plants, traveling about one foot every hour to all parts of the plant! This showed that leaves are very good at taking in food.

Sometimes, a special spray helper called a surfactant is added to the liquid fertilizer. This helps the nutrients stick better to the leaf and then get through the leaf's waxy outer layer, called the cuticle.

Foliar feeding is great because it helps plants get nutrients quickly. It also avoids a problem called "leaching-out," where nutrients wash away from the soil before plants can use them. For some nutrients like phosphorus, zinc, and iron, foliar application works much better than adding them to the soil. This is because these nutrients can get "stuck" in the soil and become hard for the plant to reach.

When to Use Foliar Feeding

It's usually best to do foliar feeding in the early morning or late evening. This is because the temperature is cooler then, preferably below 24 °C (75 °F). When it's too hot, the tiny pores (stomata) on some plant leaves can close up. If the pores are closed, the plant can't absorb the nutrients as well.

de:Dünger#Mineralstoffaufnahme durch das Blatt

See also

In Spanish: Fertilización foliar para niños