Four things you need to know about vegetable garden soil
October 13, 2017
Is your garden soil ok to grow vegetables? What should it be like? How do I know if it is good or not good? These are things we think about before planting a new season of vegetables, or when beginning a vegetable garden.
If you are beginning a vegetable garden for the first time you should have first determined the position you are going to grow is the best location. Once this is decided the soil preparation is next.
Understand that there are no quick solutions to change your soil. It is a slow process, it takes years. Getting these basics right from the start will set you up for good harvests. There is much to be learned about soil, I am still learning and will continue to do so. These four tips below are the very first things you need to begin with.
Soil structure and management is a science. If you have a technical interest soil I highly recommend you read the book The Intelligent Gardener by Steve Solomon.
1. Get your hands dirty and feel it.
Dig a small hole in the soil where you plan to grow your vegetables and herbs. Take a handful of the dirt and feel it. Good vegetable garden soil is dark, crumbly and moist. It will have worms and other small beings working in it. It will almost hold together when wet or damp. Wet the handful you have and squeeze it in the palm of your hand.
Does it stick together and feel like clay? Is it very fine like sand? Does the water run off the top? It is too rocky to absorb the water?
Feeling the soil will give you an idea of how well suited it currently is to begin growing. Different plants like different soils but generally most vegetables like a soil that drains well and has some bulk from organic matter that can hold moisture.
If your soil is very sandy, or a dense clay it is advisable to source soil and bring it into the growing area, or garden bed you wish to use for growing vegetables. (read more on this below)
When we created a new garden area in our garden a number of years ago the soil was filled with small rocks, it was dry and held no structure at all. There were no worms or other life evident. I did not want to bring soil on site so I worked through sifting the rocks and adding a bulk amount of organic matter that I continue to build in that area. It has been a great success and wonderful addition to our growing area. You can read about the steps I followed in the set up here.
Note: Be aware that all soil contains potentially harmful bacteria, especially bagged soil. Consider wearing a face mask when moving large amounts of soil and never inhale it, or pour it from a height. Wear gloves and wash hands after a session in the garden.
If you are concerned about metal contamination of your soil, Macquarie University offer testing as part of their VegeSafe program.
2. Test the soil pH
Soil is labelled as either alkaline or acidic when considering pH. A pH of 7 is considered neutral and ideal for growing vegetables. This pH allows the plants to take up the nutrients they need from the soil to grow. It is a simple, inexpensive way to gain a basic understanding of your soil. You can purchase a kit from most nurseries or hardware store for approximately $20. It is a fun activity to do with the kids and each kit will provide a large number of tests. If your soil tests as highly alkaline, or acidic any materials you add to modify the pH will take many months to register. As with the soil type, some plants prefer soil that is acidic or alkaline. For example, blueberries, and other berries, prefer an acidic soil within the range of 4-5.5 They are best grown in containers or their own garden bed to allow the soil to be monitored and the pH maintained with materials such as coffee grinds, pine needles and bark.
3. Build the organic matter in your soil
If you are starting a new vegetable garden with new soil there is no need to add additional organic matter more than once, and at least 6 months after the original set up. You can wait much longer than this if you use good quality soil and additives when you do the initial set up. When I set up a new vegetable garden, bringing soil into a garden bed I layer the soil with various materials such as straw, perlite, compost and manures to create an optimal growing medium to begin with. This information is covered in more detail in the Vegetable Garden Workbook.
If you have an existing vegetable garden as I do, I like to add a thin layer of compost to the garden beds twice per year, prior to summer planting and prior to winter planting. I also mulch the garden beds once the Summer plants have been added and begin to become established. Ongoing I add worm castings to small areas of the garden as they are ready to be harvested as well as coffee grinds and dry eggshells. Over time these materials are broken down and incorporated back into the soil.
I will write a post about mulch next week, the types and applications so be sure to return to look at that as we are approaching Summer it is an important activity. Sign up to the Weekly Updates at the end of this post and you will get it delivered to your inbox.
Manure can be a good addition to the vegetable garden. If you are growing an organic vegetable garden it is important to confirm the source of any manure used to ensure that the animal was not fed hormones and growth accelerators. This can be tricky so unless you know the source or find a bagged version that is Certified Organic (read the next point for more on this), it is best to stick with compost or non animal based additions such as mushroom compost. I wrote a post many years ago now with one of my readers on how to create compost, read it here. At some point soon I will update it! My preferred method of recycling food scraps at home is via a worm farm.
4. Choose the highest quality possible
I am sure you have heard the saying “you get what you pay for”? It is certainly true with soil if you are purchasing it.
If you have good soil, you will produce good vegetables.
The Vegetable Garden Workbook provides instructions to calculate the amount of soil needed to fill a garden bed, or x number of pots.
If you are adding bagged soil – eg: soil purchased from a hardware store or a nursery, look for the Organic Input certification. This is represented by a green bud shaped logo and the wording Australian Certified Organic. Products with this certification will be a high quality and contain no synthetic materials.
If you are bringing in cubic meters of soil you will need to do some research of local landscaping suppliers to find the best quality. There are many tips on this as well as soil additives such as manures in the Vegetable Garden Workbook. The Workbook has been designed to step you through the practical aspects of planning and setting up a vegetable garden – including the soil you are using. Purchase a copy here to help guide you in your set up, or to improve the results in your existing garden.
Stay up to date with the latest by following Kyrstie on social media.