Leave It to Fertilizer for Quick Solution

Foliar Feeding: A Fast Fix for Struggling Plants

Got any sickly plants in need of a fertilizer boost? If so, bypass the roots and spray soluble fertilizer on the leaves. Known as foliar feeding, this method has a number of benefits.

Why Foliar Feeding Works

“The main advantage of foliar feeding is that nutrients enter the plant more quickly,” said Christopher Totten, a certified ecological horticulturist for Oregon-based Whitney Farms.

“With foliar feeding, the nutrients can be absorbed into the leaf tissue within a day of application, which is faster than through the roots,” he said.

Jim Kitano, manager of Kitano’s Garden Center in La Palma, agrees. “Apply fertilizer to the leaves and it affects the plant right away, whereas fertilizer added to the soil can take days, weeks or even a month to be absorbed,” he said.

Benefits During Cold Weather

During winter, foliar feeding can be even more effective, as cold soil slows down root absorption.

Effective for Nutrient Deficiencies

Foliar feeding is especially helpful for correcting micronutrient deficiencies, like iron deficiency (chlorosis), which causes yellowing between leaf veins. When severe, entire leaves may turn yellow.

“A plant can collect almost any micronutrient sprayed on its leaves,” said James Vlamis, a plant physiologist emeritus at UC Berkeley. “In the case of iron deficiency, we’ve seen greening in four or five days.”

Additional Benefits

  • Quickly greens up yellowing plants
  • Discourages spider mites by moistening foliage
  • Works well on slope gardens where granular fertilizers are hard to apply

Important Caveats

Experts caution that foliar feeding should supplement, not replace, root fertilization.

“Nothing beats the root system for taking things into a plant. Roots were created for feeding plants.” — James Vlamis

Macronutrients vs. Micronutrients

Foliar feeding is best suited for applying micronutrients like iron, zinc, and manganese. For macronutrients such as calcium, magnesium, and potassium, root feeding remains more efficient due to the large quantity plants need.

Soil Acidity and Iron Uptake

In areas like Orange County where soils are often alkaline, iron becomes less available to plants. This makes foliar feeding more effective. Plants prone to iron deficiency include:

  • Azaleas
  • Gardenias
  • Hydrangeas
  • Rhododendrons
  • Citrus
  • Camellias

Soil Amendments for Long-Term Solutions

  • Work in compost regularly
  • Add gypsum or soil sulfur
  • Use iron chelate in the soil

Foliar Fertilizer Options

Options include:

  • Organic: liquid sea kelp and/or fish emulsion
  • Chemical: water-soluble fertilizers

Always read the package. If foliar use isn’t mentioned, ask a nursery expert before applying.

Application Tips

  • Foliar feed early in the day so leaves dry by evening to prevent fungus
  • Follow package instructions to avoid leaf burn
  • Use hose-end sprayers for large areas; atomizers for smaller areas
  • Add a surfactant (like a few drops of mild dish soap) to help fertilizer stick
  • Spray the undersides of leaves, where stomata are located for better absorption
  • Feed every 2–4 weeks depending on plant needs and fertilizer type

Julie Bawden-Davis

Julie Bawden-Davis is a bestselling journalist, novelist, blogger, and YouTuber. A prolific author, Julie writes in several genres. She enjoys creating page-turning suspense served up with a dose of romance, garden books that turn any brown thumb green, and spiritual books meant to enlighten and inspire. Widely published, Julie has written 45 books and more than 4,000 articles for a wide variety of national and international publications. She lives in Southern California, where she enjoys sunny, blue skies most days and year-round gardening. Julie gains inspiration from being surrounded by plants when she writes.