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How To Amend Soil Around Existing Plants, Trees, And/Or Shrubs?

Soil amendment creates a suitable environment for plant roots to develop and function efficiently. While amending the soil in a bare garden is relatively straightforward, you may wonder how to amend the soil around existing plants, trees, or shrubs. We did the legwork for you, and this is what we discovered.

Topdressing the soil around existing plants, trees, or shrubs with an amendment such as compost, well-aged manure, or fertilizer can aid in improving it. To do this, follow these steps:

  1. Identify the ways you need to improve the soil.
  2. Remove any existing mulch.
  3. Apply the amendment.
  4. Add a new mulch layer.

Dive in to learn more about soil amendment. We will elaborate on why you need to amend the soil and offer tips for choosing an ideal amendment.

Eco friendly gardening. Woman preparing soil for planting, fertilizing, How To Amend Soil Around Existing Plants, Trees?

Amending Soil In An Established Garden

Amending Soil In An Established Garden - A women harvests fresh worm castings (compost) from a vermicomposter on her balcony

Trees and plants only bear fruit if they have ideal conditions for fruitfulness. These requirements include adequate water and necessary nutrients absorbed from the soil through the roots.

But sometimes, the soil lacks sufficient supplies to aid with growth. For this reason, you may consider amending the dirt to supplement what is lacking.

The ideal approach to revitalize the soil around existing trees, plants, or shrubs would be top-dressing around the vegetation with one or two inches of compost. You can also use well-aged manure, fertilizer, or shredded leaves instead of compost. This approach helps you avoid digging out the plants.

When To Amend The Soil

When To Amend The Soil - Worker pours a tank of liquid plant nutrient on the tree base after it has been transplanted.

Pick the right time to amend the soil. You want to ensure that the nutrients are available during the peak seasons of uptake by the plant. Furthermore, there should be sufficient nutrients for your plants, trees, and shrubs at critical development stages.

You can also consider amending the soil before it rains to improve its drainage and water-holding capacity. Consequently, you will be able to reduce the plants' watering frequency.

The ideal time to mend the soil depends on the amendments you use. It is best to apply slow-decaying compost or manure in the fall to allow enough time - throughout winter - for the dirt to assimilate the nutrients.

Also, the plants experience slower growth in autumn, thus requiring minimal nutrients during this season. Furthermore, the weather conditions are better suited for amendment than in the wet spring.

Fertilizers decompose rapidly. So, it is advisable to amend the soil early to mid-spring using fertilizers instead of compost. 

Step-by-step Guide

1. Identify The Need

Begin by determining how to improve the soil since this will help you pick out supplies for the amendment. Is the soil lacking nitrogen, or do you need to enhance aeration or drainage? Do your plants need more phosphorus or magnesium, or should you alter the soil's PH level?

You can carry out a soil test to help identify the need. You will need a testing kit, a bucket, and a  garden trowel to perform the test. 

  1. Use the garden trowel to pull up soil samples from around your plants, trees, or shrubs. Collect portions from different spots in the garden to get a more accurate assessment of the condition of your garden soil.
  2. Combine the different soil portions in a bucket, then scoop a sample from the mixture for testing.
  3. Test the sample and interpret your readings. The kit will help you check the soil's PH and also identify its nutritional composition.

This soil test kit can analyze any soil type in various gardening conditions. See it on Amazon.

2. Remove Any Existing Mulch

Remove Any Existing Mulch - Eggshell is fertilizer in the soil

Mulching aids in shielding plant roots from heat or cold, controlling weed growth, and retaining moisture. Although you leave mulching on the surface, soil improvement involves blending the amendment with the dirt. 

Removing the old mulch can improve the soil's aeration and drainage. Furthermore, it is easier to mix the amendments into the dirt in the absence of mulch.

3. Apply The Soil Amendment

Apply The Soil Amendment - Eco friendly gardening. Woman improving garden bed soil for planting

Different plants require different growing conditions. So, add only what the plant needs.

When using fertilizer to enrich the soil, ensure that you measure the required amounts since adding too much can harm the plant.

Carefully apply the soil amendment around the plants, trees, or shrubs, then lightly mix it with the soil. Take care not to sprinkle the fertilizer on the vegetation's leaves or stems to avoid burning them. If you accidentally spill fertilizer on the plants, gently wash it off.

If you use compost or well-aged manure to improve the soil, scatter the amendment, then use a handheld garden fork to mix it with the dirt. Mix gently to avoid damaging the vegetation's roots.

4. Add A New Mulch Layer

Please be careful when adding a new mulch layer. Avoid adding too much mulch at the base of your vegetation since it can cause your plant's health to deteriorate. Worst-case scenarios can result in the death of trees, plants, or shrubs.

Why Do You Need Soil Amendment?

The steps taken in soil amendment aim at creating a better soil constitution to foster plant productivity. You can do this by mixing organic or inorganic substances into the soil. 

Improves The Soil's Water-Holding Capacity

Mixing soil with organic matter increases its magnetism to water since the organic matter particles have a charged surface that draws water so that it sticks to the surface.

You enhance the soil's water-retention capacity through amendment. The soil's water-holding ability is the quantity of water it holds for the vegetation's use.

The plant or tree may wilt if the roots cannot mine sufficient moisture from the soil. In addition, the plant may experience slow growth, and the leaves may dry out. Consequently, your tree may fail to bear fruits in season. Eventually, the plant or tree may die.

Enhances Soil Structure

Soil structure influences how easily water, air, and roots can move through the soil. Incorporating organic matter in the subsoil can aid its structural development by increasing the pore space between soil particles. 

You want to ensure that the soil you plant your vegetation fosters unrestricted root growth, free air movement, and drains well. 

If the soil particles are pressed together, water infiltration and drainage will be reduced since the water has difficulty moving downwards. Also, the soil will be poorly aerated due to a reduced rate of gas exchange. Finally, roots will need to exert more force to penetrate the soil.

Enriches The Soil With More Nutrients

Enriches The Soil With More Nutrients - Eco friendly gardening. Woman preparing soil for planting, fertilizing with compressed chicken manure pellets.

Plants absorb nutrients from the dirt via the roots. As organic matter, made of decaying plants or animals, disintegrate, they release nutrients into the soil, enriching it. Organic matter is a crucial source of sulfur, nitrogen, and phosphorus.

Vegetation needs nitrogen for leaf formation and maintaining the green leaf color since it is a component of chlorophyll. Additionally, nitrogen is vital in several enzyme reactions. Sulfur also aids in the execution of enzyme reactions.

Phosphorus aids in seed formation, root development, and crop maturity. It also empowers the plant to fight diseases.

Topdressing the soil with Epsom salt can improve its magnesium content. Magnesium is vital in the plant's flowering and fruiting process. 

Please read this article to discover: 3 Best Epsom Salt Products For Plants.

Creates Suitable Living Conditions For Soil Organisms

Creates Suitable Living Conditions For Soil Organisms - Searching for bacteria on surface

The microorganisms in the soil, primarily bacteria, and fungi, break up the decaying substances in animals and plants into a state that the roots can absorb.

You can create better living conditions for the soil organisms through soil amendment since they need food, water, and air to survive. 

How To Choose A Soil Amendment

How To Choose A Soil Amendment - composter with organic waste on the garden

Examine these factors to choose an ideal component to amend the soil.

Check The PH Level And Salt Content

Take care not to use amendments with high salt content since they can burn the plant roots, causing death. Compost comprising plant-based materials like wood chips contains lower salt levels when compared to manure-based compost. Therefore, plant-based compost is a good amendment.

Please note that uncomposted wood products disintegrate slowly and can alter the soil's drainage or tie up nitrogen. Therefore, they are not suitable amendments. But you can use the wood products once you compost them.

Biosolids may contain high salt levels, which can harm your plants. Moreover, they can contain heavy metals such as lead and cadmium. So, it is sensible to avoid using biosolids to amend the soil in a vegetable garden.

You can use sphagnum peat to amend sandy soils. This amendment will improve the soil's water retention capacity. Additionally, it has a low PH level and can be used to create a favorable environment for growing plants that require acidic conditions.

Inspect For Pathogens

Fresh manure can contain pathogens such as E Coli, which can harm human beings if ingested. You can introduce these harmful pathogens by eating the fruits and vegetables you harvest from the section that you treat with fresh manure. Moreover, it has elevated ammonia levels which can damage the plants.

Use composted or well-aged manure instead of fresh manure to obtain the best results. Composted manure is taken through multiple active heating cycles at temperatures above 145°F to kill pathogens and weed seeds.

On the other hand, the manure releases excessive ammonia over time, thus becoming ideal for soil amendment when well-aged. However, the aged manure may still contain viable weed seeds.

Examine The Soil Texture

The soil texture will help you pick a suitable approach based on whether you intend to increase or reduce the soil's bulk.

If your garden has clay soil and you wonder how to amend it, please read this article: How To Amend Clay Soil For Vegetable Gardening.

Final Thoughts

Soil amendment can improve its water-holding capacity, enhance its structure, add nutrients to the soil and create a favorable environment for soil organisms to thrive. To improve the soil, you can use organic matter, such as compost and well-aged manure, or inorganic matter. 

Ensure that you identify the need you intend to address through soil amendment and then choose a suitable one. It is advisable to remove the mulching before applying the amendment and then replace it afterward.