When To Use Garden Soil
Trust me, I’ve been there. You just came home from the nursery with beautiful flowers for your containers. Garden soil can be used in containers. You grab a shovel and start digging up some soil from your garden to fill the containers. It is tempting to use garden soil in pots, but it is not recommended. Garden soil can become very compacted when it is used in containers. Garden soil lacks nutrients and drainage that are necessary for healthy potted plants.
Types Of Garden Soils
There are many soil types that can be used for your home garden. Each one has its own unique characteristics.
- Dirt from your garden at home
- Buy bags of garden soil at the store
- Potting soil, potting mix
- Mixture for seed starting
Garden Soil From Your Yard
Your yard’s soil is full of all kinds of goodness. However, if you dump garden soil or topsoil in a container it won’t make a healthy garden. Your garden soil is heavy, and will vary depending on where you live. It’s aerated by the microorganisms, worms and bugs that live in the soil when it’s laid on the ground. However, garden soil from your backyard can become too dense when it is used in containers. The soil will become very dense, which can cause poor drainage in the container and eventually lead to root rot.
Topsoil bags purchased in a shop are comparable to what you would find in the ground. The amount of silt, clay, and sand will vary depending upon where the topsoil was harvested. Bagged topsoil differs from soil from your yard in that it is shredded and screened to remove large particles before being processed to looser consistency.
Garden soil and topsoil can be too heavy and dense for container plants.
Bagged Garden Soil
Bagged garden soil is made up of organic topsoil, sand and bulky organic/woody material like pine bark. Garden soils can be too dense to allow air and water movement in a container garden. In their tiny pores, soils can hold water well and can drown roots, especially in small containers.
Many websites will confirm that 100% compost can be used to plant containers. This is not something I’ve tried before with bagged compost. This may be possible if you use leaf mold to make your compost. It will work well in containers. If you are using regular compost, bagged compost, or any other type of compost, I recommend mixing it with at least 50% soilless compost mix to ensure it doesn’t compact.
Many gardeners will substitute peat with compost in their homemade potter mix – it retains moisture but not as well as peat.
For growing vegetables, plants and flowers inside pots, potting soil or potting mix is the best option.
Although vendors might call their product either a potting mixture or a soil, there is often no distinguishing ingredient. On the bag’s back, the ingredients will be listed.
The Typical Potting Mix contains:
- decomposed/woody material (around 50-65%)
- sphagnum peat moss (or equivalent)
- Perlite and/or Vermiculite
- A wetting agent
Important to remember that potting mix differs from seed starting mix. Seed starting mixture is used for germinating and growing plants from seeds. Seed starting mix contains no soil. You don’t need to use garden soil or pot soil to make a seed-starting mix.
Can garden soil also be used in pots for outdoor use?
You can use garden soil as a base for a homemade potting mix. However, it is not recommended to be used in outdoor pots. It is better to use a potting mix for the best balance of nutrition, drainage, moisture retention, aeration and drainage.
What happens when you put garden soil into pots?
Garden soil such as Vigoro Garden soil or Miracle Gro Garden soil can cause problems. The weight of garden soil makes containers more difficult to transport than if they were filled with potting mix. Compaction will result from overwatering. Compaction will prevent the pot from draining and will result in no air for your plants. Garden soil will not have the nutrients that your plants need, as a soilless mix is already in the bag.
If you insist on using garden soil, amend the soil to increase the soil’s moisture retention, drainage and nutrient levels. To get more ideas, scroll down to the section “What can you use in containers instead of potting soil?”
I accidentally put garden soil into pots. Will this kill my potted plants?
Potted plants can be killed if you use soil from your backyard. You can still fix it, but don’t panic! You will first need to remove the plant from its pot. Instead of throwing out the soil you have put in your container, you can pour it into a bucket to amend the soil.
The next section will provide you with several options for amendment.
Mixing potting soil and garden soil is possible.
For certain cases, such as raised beds or other situations, potting soil can be mixed in with garden soil. However it is not recommended for use in containers. The mixture will still need to be amended.
What is better than potting soil for containers?
Mixing different ingredients can make your own potting dirt. Gardeners tend to use perlite, vermiculite, and peat with sphagnum or sphagnum. Remember that potting mixes must contain “ingredients” that retain moisture, promote drainage, aeration, and nutrients.
I prefer to use 1 part moisture retention material to 1 portion drainage and aeration substances plus the proper amount of nutrients. This will depend on what fertilizer you use as well as the size of the container.
This recipe will help you decide what materials you should use.
- 1 part woody material, topsoil or garden soil
- 1 part perlite (for drainage)
- 1 part coco coir (for moisture retention)
- Bone meal (balanced fertilizer).
Here are some more creative options for you!
1. Drainage & Aeration
What are some ways to aerate and drain your mix?
- Perlite:Perlite, a volcanic glass, is heated to high temperatures. It expands when heated, creating an odorless solution that feels almost like Styrofoam. It’s great for drainage.
- PBH Rice Hulls: At a lower cost than perlite, PBH rice hulls significantly reduce dust in the greenhouse mix environment. Although sterilized rice hulls do not replace peat moss, they can be used to replace vermiculite and perlite.
- Horticultural Sand: horticultural sand consists of very fine sand that is made from crushed granites, quartz, or sandstone. You can also call it sharp sand (or coarse sand) or quartz sand. Horticultural sand encourages drainage because it has a mixture of gritty and fine components.
2. Moisture Retention
Another important element of soil in potting mix is moisture retention. You should always include a component for drainage and a moisture retention component to your soil. Your soil will eventually become dense and brick-like, making it difficult to drain. This is bad news for your plants. What are some ways to retain moisture in your mix?
- Peat Moss : Although peat moss is the best option for moisture retention in seed starting or potting mixes, it is not sustainable or environmentally-friendly.
- Vermiculite: Vermiculite is a natural mineral (magnesium-aluminum-iron) silicate, which basically means minerals compressed and dried into flakes, or pellets. It is a water- and moisture-retention aid. Because it protects seedlings against fungus, vermiculite is a common ingredient in many seed-starting mixtures. Vermiculite has some drainage, aeration and other qualities but not as much as perlite.
- Coco coir: I love coconut coir . Also known as coco fiber, coco peat, or coco coir, is my favourite alternative to peat moss. It is water-holding and pH 6 so it will be good for most garden plants.
- Compost Many gardeners recommend compost to replace peat moss. However, if compost is used in containers, it can become compacted and cause drainage problems.
- Leaf mold: Leaf mould is simple to make , can condition soil and improve moisture retention.
- Woody materials Locally-sourced woody byproducts (e.g. wood fiber, sawdust, or composted bark), can be an alternative to peat moss. It’s a less-than ideal alternative to peat moss because the majority of wood can be chemically treated and isn’t local.
- PittMoss: Invented in Pittsburgh by an inventor, PittMoss is made up of reconstituted fibers and proprietary ingredients.
- Worm casts: Worm casts are the leftovers from farmed earthworms. They are rich in nutrients, and have beneficial microbes. They can also hold 2-3x the weight (p35), in moisture.
If you want your plants to thrive, they will need fertilizer. They only have the nutrients they need because they are contained in a container. It is important to add fertilizer to DIY potting mixes and to replenish it often.
Usually, you will see three numbers on a fertilizer label when you buy it. These numbers are the number of nitrogen (N), P (or K) in fertilizer or the ratio N-P-K. A fertilizer labeled 10-5-10 indicates that it contains 10% N, 10% P, and 10% K.
Nitrogen Promotes optimal shoot and leaf growth. However, this can often come at the cost of fruit and flower production. Phosphorus promotes strong roots, encourages fruiting, and flowering. Potassium levels can influence a plant’s health and vitality . A balanced fertilizer should contain equal amounts of each of the three nutrients.
These are some recommendations for fertilizers to make your own potting soil out of garden soil.
- Miracle-Gro All-Purpose Food: This fertilizer is affordable and works well with most plant types. This is an artificial solution that contains chemicals and it is not organic. I am also offering some other options.
- Osmocote: Osmocote is a common fertilizer for container gardening. It contains 11 nutrients and slow-releases feeding container plants for six months.
- Worm casts: Worm casts are made from the farmed earthworms’ waste. They are rich in nutrients, and have beneficial microbes. Worm castings have a higher moisture retention than standard potting mixes and can last 6x longer (p35).
- Lean Meal Bone Meal: This meal is made with steamed and crushed animal bones. It is high in Phosphorus which is important for root development and flower blossoms. Also, it has calcium and nitrogen that are very beneficial for plant growth.
- Blood Meal is dried and powdered blood meal. It is used to fertilize soil nitrogen levels. Without nitrogen, plants cannot grow. Blood meal, which is one of the richest sources of non-synthetic nitrogen, is an essential component of plant cells. It is also one of the basic components for chlorophyll. This substance helps plants convert sunlight to sugars.
- Fish-based fertilizers, liquid kelp and seaweed provide many benefits for plant growth and health.
It is not a good idea to use garden soil in containers. Garden soil by itself is not suited for successful container gardening. It lacks the nutrients, moisture control, drainage and aeration that are required to grow plants in containers. Garden soil and topsoil can become so compacted in containers that it is impossible for water to drain.