Skip to Content

Lilly Miller Moss Out: Complete Guide for All Applications

Lilly Miller Moss Out: Complete Guide for All Applications

While moss may appear vibrant and verdant, it is typically considered an undesirable presence in your lawn or garden.

Moss is unique among plants because it does not have a root system or vascular system. It thrives in moist, low-light conditions where other plants struggle to grow.

Lilly Miller Moss Out is a line of products that effectively kill moss.

Does Lilly Miller Moss Out work? The Lilly Miller Moss Out line of products uses iron and zinc compounds or ammoniated soap of fatty acids to quickly and effectively kill moss in lawns, in flower beds, on roofs, or in walkways. For the best results, remove as much moss by hand before applying.  

As is the case with any product, it is best to choose the right one for your needs and apply it according to package directions.

Below, we’ll cover the different types of Moss Out, take a closer look at the ingredients, and discuss when and how to apply it correctly.

How Does Moss Out Work?

Whether it is the iron compounds, zinc compounds, or ammoniated soap of fatty acids, the active ingredients in Moss Out products draw moisture from the moss.

By drying out the moss, the moss cannot survive. After applying Moss Out, the moss will turn black and die. 

How Many Kinds of Moss Out Are There?

Lilly Miller Moss Out offers a variety of products to fit your needs. Most formulas are available in liquid and granular forms. 

Moss Out for Roof

The liquid version of Lilly Miller Moss Out for Roof comes in a ready-to-use version and a concentrated formula.

The active ingredient is ammoniated soap of fatty acids, which draws moisture from the moss, effectively killing it.

This iron-free formula will not leave rust stains or corrode gutters. Most users see results within hours.

The granular formula of Lilly Miller Moss Out for Roof has zinc compounds as the active ingredients. The product comes in a shaker container for easy application.

The granules can be dissolved in water and applied with a sprayer. 

Moss Out for Lawns

Just like the roof formula, Moss Out for Lawns comes in liquid and granular forms. The liquid Moss Out for Lawns comes in a ready-to-spray formula or a concentrate.

Liquid iron gives the fastest results for killing moss on your lawn. Results can be seen within hours. 

Moss Out for Lawns granules contains 10% iron, which kills unwanted moss while nourishing the grass.

The granules need water to be activated, so apply before rain or water after application. Results can be seen within hours of water activation. 

Moss Out Plus Fertilizer

To get all the benefits of Moss Out for Lawns while helping your grass grow stronger and healthier, use Moss Out Plus Fertilizer.

This product contains a high-nitrogen fertilizer to promote greener lawns while removing unwanted moss. Healthy grass can help prevent future moss growth. 

Moss Out Spot Treater

If you are looking to eradicate moss from your flower beds or shrubs, Moss Out Spot Treater is a great option.

These granules can be easily applied to smaller areas of moss in lawns, beds, or shrubs.

This iron-based formula is extremely effective at killing moss, but it can also burn sensitive foliage on shrubs and flowers.

Apply only to the ground, and clean off any granules that accidentally make it onto nearby plants. 

Moss B Ware

Moss B Ware is similar to Moss Out for Roof. This product can be used on roofs, walkways, and patios to quickly kill unsightly moss.

The formula is iron free so you won’t need to worry about rust stains or corrosion. The granules can be dissolved in water for application. 

Does Moss Out Hurt Nearby Plants?

Moss Out does not harm the grass on your lawn. However, the iron-based formulas can burn sensitive foliage on flowers and shrubs.

To prevent damage, apply the product to the soil and not the plants. If any Moss Out gets onto plants, brush or rinse it off immediately. 

Lilly Miller Moss Out Ingredients

All the active ingredients in Moss Out products work to draw water out of the moss, killing the plants. For lawns, an iron compound is most effective.

Zinc compounds and ammoniated soap of fatty acids are used in the roof and walkway formulas to prevent rust stains from iron. 

When To Apply Moss Out

It is best to apply Moss Out during periods of moss growth. For most climates, this is the wet spring and fall. In warmer climates, moss growth may be more prevalent in winter.

It does not matter what time of day you apply Moss Out. Just remember that granules need to be watered after application for best results. 

Several cans of Lilly Moss Moss Out! Spot Treater.

Lilly Miller Moss Out Directions

Moss Out for Roof

To apply the liquid product to your roof, connect the bottle to a garden sprayer. Before spraying, try to remove as much of the moss as possible by hand.

If the moss is dry, apply a little bit of water first. Spray Moss Out evenly over the moss-covered areas. This product can be reapplied as necessary. 

The granules can be applied as a powder from the shaker. You can apply a light misting of water to help activate the product. For best results, do not apply before a period of heavy rains.

Moss Out for Lawns

For best results, cut the grass as short as possible. Rake up as much moss as possible. Apply the liquid or granular Moss Out for Lawns to the affected areas.

You can lightly water the area if granules were applied. Apply Moss Out for Lawns when heavy rains are not expected for a week or more.

Moss Out Plus Fertilizer

Moss Out Plus Fertilizer can be applied just like Moss Out for Lawns.

Since this product contains high amounts of iron and nitrogen, do not get Moss Out Plus Fertilizer on shrubs or flowers. The nutrients can burn the sensitive leaves. 

Moss Out Spot Treater

Moss Out Spot Treater is best used on small areas of moss in your garden. Evenly apply the granules to the affected area.

If using this product in a flower bed, avoid getting Moss Out on shrubs or flowers. The sensitive leaves can be burned by the high iron content. Gently water the area to activate the granules.

Moss B Ware

The most effective use of this product is to shake the granules over the affected area. Gently water or allow light rains to dissolve the product to penetrate the layers of moss.

Dead moss can be removed after a couple of weeks.

Lilly Miller Moss Out Spreader Settings

On a scale of 1-10 (10 letting out the most product), it is recommended to use your spreader on a 3 for Moss Out.

This usually allows the product to evenly spread the product at a rate of 20 pounds per 4,000-5,000 square feet. 

Do You Need To Water Moss Out?

Granules need water to activate the product. If you are not expecting rain, you can gently water the application area.

Too much water can overdilute the Moss Out, so do not apply before periods of heavy rain.

Can You Use Moss Out on Flower Beds?

The best Moss Out product for flower beds is the Moss Out Spot Treatment. This shaker container makes it easy to apply the product to moss on the soil.

Shrubs and flowers can suffer burns from the high iron content in Moss Out, so it should never be applied to the plants. 

Does Moss Out Kill Algae?

The only Moss Out products that also kill algae are the ones that contain ammoniated soap of fatty acids. This includes the liquid formula of Moss Out for Roof.

Can I Use Moss Out Before It Rains?

A light rain after a Moss Out application is fine. However, heavy rains can overdilute the product, rendering it ineffective.

It is recommended to apply Moss Out when you are not expecting rain for a few days. 

Lilly Miller Moss Out and Pets

Lilly Miller Moss Out products are considered generally safe for pets. It is best to keep pets away from application areas until the product has dried.

Additionally, store Moss Out away from pets (and children). 


Lilly Miller Moss Out products are effective at killing existing moss and preventing future growth. However, the most effective prevention is correcting the environment so moss cannot grow there.

This includes filling in low spots in the yard, trimming trees to let more light to the ground, and stopping overwatering.

Even if you end up with new moss growth, you’ll always have Lilly Miller Moss Out products to help you get rid of it.

Image credits: Diana Barry, Curt’s Premium Outlet