Dry, poor, sandy soil is one of the challenges homeowners face when aiming for a beautiful lawn. Fortunately, getting your soil into good shape shouldn’t be too painful of a headache. To offer a helping hand, we bring you this guide on how to amend sandy soil.
Once you’ve improved your sandy soil you’ll realize that these soils can be very productive, growing prolific vegetables and robust trees, shrubs, and flowers — and even grass. Come along as we discover more about sandy soils and how to make the most of them in your lawn.
The Root of the Problem
Why is sandy soil such a nuisance for homeowners? Well, the soil is the foundation for any plant, providing both moisture and nutrients vital for healthy growth. But there are three main problems when trying to cultivate a lawn with this kind of soil:
- Dryness: Soil particles in sandy soils are relatively large and coarse, with an abundance of air pockets between them. This causes water to be drained promptly, so the soil cannot provide the consistent moisture retention most grass types need.
- Nutrient storage: Similarly, sandy soil lacks the ability to hold onto nutrients and has very few nutrients of its own. So fertilizing is a fruitless effort. This causes nutrient deficiency symptoms like stunting, yellow leaves, sparse flowering, or poor fruit production.
- Lack of microorganisms: Healthy soils are filled with billions of tiny, microscopic cute little organisms that help plants by cycling nutrients and suppressing plant diseases. However, sandy soils lack the presence of such organisms, and therefore, grass growth is impaired.
To learn more about the different types of soil, check out our Guide to Soil Types: Pros, Cons, and Plant Suggestions.
How to Test for Sandy Soil
You already know you have sandy soil but want to be sure before taking measures. Here is the manipulative test to know if you have sandy soil:
- Wet a handful of your soil until it begins to stick together
- Roll it into a ball of approximately 3 cm
- Put the ball down: If it falls apart, it’s sand. Sandy soils are too dry to hold the shape.
Once you’ve verified your soil, you can move on to the next step: amending your soil.
How to Amend Sandy Soil
Here is the good news: There’s an easy and inexpensive solution to correcting sandy soils — organic matter! Adding organic matter as a soil amendment will:
- Increase the soil’s ability to hold water and nutrients
- Create the perfect habitat for the essential microorganisms that live in healthy soil (which are lacking in sandy soil)
- Reduce the need for fertilizers: The humic acid in organic matter liberates nutrients present in the soil while the humus surface itself stores them for plant usage.
Given all of these benefits, we bring you the best practices for using organic material to amend your sandy soil.
Topdressing with Compost
This process consists in spreading compost on top of your grass. Topdressing help sandy soils by:
- Enhancing soil structure: Topdressing with organic matter or compost helps balance out the amount of air space in sandy soil, which improves its water-holding capacity and nutrient retention.
- Improving fertility: Compost can provide essential nutrients and minerals that the soil lacks, improving fertility and helping plant growth.
- Increasing microbial activity: The organic matter will provide food for soil microbes, which can break down the material and release nutrients into the soil, thereby enhancing soil microbial activity.
- Reducing erosion: The topdressing layer protects the soil surface from wind and water erosion.
Topdressing is a simple process. Here’s how to topdress your lawn:
- Check the soil pH. If it’s outside of the ideal range for your grass, apply the necessary soil amendments.
- Mow the grass at the minimum height recommended for your grass type.
- Dethatch or aerate using a power rake, dethatching machine, or an aerator. This ensures the topdressing material has better contact with the soil.
- Clean up any debris such as grass clippings or soil plugs from the dethatching or aerating process.
- Spread the material onto the lawn using a shovel. Water or rake it in so it evenly penetrates the soil.
Mulch is a layer of any material applied to the ground. Applying organic mulch to the soil surface will:
- Retain moisture
- Suppress weed growth
- Increase levels of organic matter as the materials decompose
- Moderate soil temperatures (warmer during winter and cooler during summer)
- Prevent or reduce soil erosion
Pro tip: Use grass clippings as mulch as a way to avoid waste! Besides, fresh grass clippings contain high levels of nitrogen, which acts as a fertilizer for the soil.
Growing Cover Crops
Cover crops — also called green manure — are plants grown outside of season as a way to protect the soil from erosion and improve its structure. They also fix nitrogen in the soil, adding nutrients that can be used by other plants. Homeowners can plant them during fall so they can be incorporated during spring.
Some plants that can be used as cover crops are:
- Annual rye
- Legumes (a vegetable garden will nourish you and your soil!)
An additional important note: Water evaporation is a major problem when dealing with sandy soils. At the same time, an adequate water amount must be present for the microbes in the organic matter to work faster.
Water in smaller amounts, around 1/3 of an inch, but more frequently, three times per week, so plant roots can grow deeper.
Sandy soils are known to be:
● Dry: Sandy soils have a coarse soil texture and gritty feel due to their large particle size and low water retention capacity.
● Warm: Sandy soils absorb heat very quickly, so during spring and summer, they’ll warm up easily.
● Light: Clay and loam soils are heavier than sandy soils, which are very light. In sandy soils, the sand proportion is greater than the clay in the soil, making the soil lightweight.
Adding clay to sandy soil is not a good idea. If the wrong proportion of clay soil is used, you’ll end up with concrete-like soil rather than a healthy, rich loam.
There are plenty of amendments that work well to transform sandy soil into a loamy paradise:
● Compost, or, in other words, decomposed organic material. You can either purchase it from your local nursery, or you can make compost yourself.
● Manure, which is animal waste, is effective in nourishing the soil.
● Cover crops help hold nutrients while reducing soil erosion and topsoil loss.
● Other organic matter such as leaf mold and sphagnum peat moss can also be used to enrich almost any poor soil, including sandy soil.
Sandy soils are a simple problem to solve. Adding organic matter is an easy way to enrich your garden soil and work towards a beautiful lawn. Hopefully, after reading this article, you can now take the necessary steps to amend your sandy soils.
If you have any other questions about lawn care or think you need help to amend your sandy soil, contact a trusted local lawn care service provider!
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