Retaining Soil Moisture-Smart Water With Hygroscopic Humectants

June 7, 2024

Understanding Hygroscopic Humectants

first splash of water

Hygroscopic Humectants: Smart Water Idea for Your Garden

What Are Hygroscopic Humectants?

Hygroscopic humectants are remarkable materials that play a crucial role in efficient water management for plants. They attract water vapor from the air within the soil, converting it into liquid form. By doing so, they ensure that water remains available for plant roots, preventing wasteful evaporation. These dual-action compounds draw in moisture (the hygroscopic part) and retain it (the humectant part). In today’s world, where water costs are rising and availability is decreasing, hygroscopic humectants are invaluable for gardeners.

Many of these materials contain organic ingredients that also serve as nutrients for plants.

How Do They Work?

Hygroscopic humectants are chemical compounds that attract water vapor from the atmosphere within your soil, condense it into a liquid form, and then retain it for the roots to use. You can put a little bit of the powder form on a sheet of plastic and within a few minutes watch it take water from the air and become wet.

The hygroscopic part can attract moisture from the water vapor in your soil.

A humectant will draw that water to the roots of your plant and hold it within the soil for the plant to use.

Not A Wetting Agent

Many of us have employed wetting agents, especially for hanging baskets that will dry rapidly in summer heat. A wetting agent will allow water to spread rather than bead and therefore provide more useful humidity to the plant.

How Can Hygroscopic Humectants Work for Us

roots taking up water

Cost and Labor Savings:

  • Using hygroscopic humectants offsets their cost by reducing water consumption.
  • Less frequent watering also saves on labor.
  • As water costs rise and labor becomes more expensive, these materials help keep gardening affordable.

Application Tips:

  • Apply during seeding or sodding to promote seed germination.
  • Use on established lawns before expected dry periods.
  • Wet the lawn before applying to ensure it reaches the soil effectively.
  • There are several competing products available, follow the instructions for the version you choose.

Effectiveness and Forms:

  • Available in both dry and liquid forms.
  • Apply using a backpack sprayer or garden hose, similar to liquid fertilizer.
  • Pre-spray the lawn with water to aid product penetration.

Features of Hygroscopic Humectants

  1. Impact on Water Management:
    • Using hygroscopic humectants offsets their cost by reducing water consumption.
    • You’ll also save on labor, as less frequent watering is needed.
    • The cost and availability of water is rising, and labor costs are increasing also. Studies show that water costs in many communities have risen by 25-30% and in some places by 300%! (Benefits of Consumable Water Management.) Gardeners and growers also deal with repeated drought incidents, and water restrictions and extra watering will increase labor costs. Anything that saves on water and labor is a benefit in the garden and keeps some growing activities affordable.
  2. Application of Hygroscopic Humectants:
    • Apply the product during seeding or sodding, as it promotes seed germination.
    • Use it on your established lawn before expected dry periods or droughts.
    • Wet the lawn prior to appliation.
    • the material, this will prevent the product from staying on the foliage or grass blades and slide down to the soil where it can work.
  3. Effectiveness and Use:
second splash of water
  • The product comes in both dry and liquid forms.
  • Apply it with a backpack sprayer or through your garden hose, just as you apply liquid fertilizer.
  • Pre-spray the lawn with water to ensure the product reaches the soil
  • Amount to use: Brand names vary but expect to use about 9 oz. for each 1000 square feet of liquid form and this should last 90 days.

More Water-Saving Tips

Additional Water-Saving Tips:

(You might like this for Water-Wise Container Gardens.

  • Water early in the morning to prevent evaporation. Morning temperatures are cooler and give the plants time to absorb moisture before evaporation begins.
  • Choose grass varieties suited to your area.
  • Leave grass blades taller (around 3 inches) to shade plant roots.
  • Leave grass clippings on the soil—they break down and enrich it.
  • Amend the soil for healthy plant growth.
  • Regularly maintain your irrigation system.

For some general watering help read ‘Water The Garden Not The Plants.’

Benefits To Your Garden:

Hygroscopic Humectants, indeed offer a promising solution for water conservation in gardening. They work by attracting and retaining moisture from the air, which is especially beneficial in areas facing water scarcity or drought conditions. By using these materials, you can maintain a lush garden while significantly reducing water usage and costs

When To Apply:

  • During Seeding: Apply to promote seed germination and establishment.
  • Before Dry Periods: Treat established lawns before droughts to maintain hydration.
  • Proper Application: Wet the lawn first to ensure the material reaches the soil effectively.

For effectiveness:

  • Forms: Available in both dry and liquid forms.
  • Application Method: Use a backpack sprayer or garden hose for distribution.
  • Dosage: About 9 oz. per 1000 square feet for the liquid form, lasting approximately 90 days.

Additional Tips to Conserve Water:

Water is our lifeblood, essential to us as it is essential to all living things. Gardeners have always been on the frontlines of finding, using and maintaining our water. Today using water is more important than ever. Here are some proven steps to get the most from it.

  • Water Early: Do it in the morning to reduce evaporation.
  • ‘Right plant right place.’ Know and use your plant’s requirements as to sun, soil, water, and nutrition.
  • Right Grass Type: Select varieties that are well-suited to your local climate.
  • Grass Height: Keep it around 3 inches to shade the roots.
  • Soil Health: Amend the soil and leave grass clippings to decompose.
  • Mulch and cover the soil with organic materials that will maintain even temperature, reduce weeds, and save water.

Help from Hygroscopic Humectants

  • Attract Moisture: They draw water vapor from the air and convert it into liquid water, keeping the soil moist.
  • Reduce Evaporation: Water is retained in the soil, minimizing loss through evaporation.
  • Enhance Plant Growth: The retained moisture supports plant growth and helps in nutrient uptake.
  • Optimize Watering: They allow for deeper watering and longer intervals between watering sessions.
  • Save Resources: Using these materials can lead to cost savings on water and labor.

Where Hygroscopic Humectants Have Been Tested:

These humectants have been tested at several universities, indicating their effectiveness and reliability. Incorporating them into your lawn care routine can be a smart move towards a more sustainable and cost-effective garden. If you have any more questions or need further assistance, feel free to ask!


In summary, maintaining a beautiful lawn and garden while conserving water is crucial. Consider using hygroscopic humectants to help achieve this balance. These products are readily available at retail stores and are easy to use. Will you incorporate them into your lawn care routine?