How to improve clay and sandy soil and create your own compost
watch my Q&A
In my sustainable living questions and answers series I cover some of the most commonly asked questions from my YouTube channel and social media accounts. This is my first question and anaswer topic, which is incredibly important as it covers 3 crucial elements when it comes to gardening, growing your own food and living more sustainably.
These topics cover “How to improve clay soil”, “How to improve sandy soil” and then “How to make compost”. In this video I talk in detail about these 3 items and show you how to make it work for you and provide you with the tools and knowledge you need to make sure you are able to grow food in clay or sandy soil and make your own compost to keep feeding your soil.
Below I provide a detailed written overview of what’s covered in my video.
How to improve Clay Soil
Why do we want to improve clay soil?
Clay soil poses 2 main issues, which sit on opposite sides of the spectrum. Either clay soil is stodgy and waterlogged or it is dry and rock hard. There is little middle ground where the soil is in perfect growing condition. So, what we need to do is create an environment in the clay soil where there are not opposite ends, but rather a happy middle ground, so that vegetables can thrive.
How can you improve clay soil?
To create an environment that is not overly wet or bone dry, you need to get as much organic material into and on top of your clay soil as possible. By adding organic matter to the soil we are able increase aeration and create an underground living environment where living soil organisms break down organic materials and start creating a undergound ecosystem that feeds the plants and creates the perfect growing environment.
What are we going to do to improve clay soil?
- Always make sure we have something actively growing
- Use cover crops and green manures to build underground biomass (clover, wheat, oats, broad beans)
- Work wood chips into the clay
- Use biochar where possible and work into the clay soil
- Add animal manures as thick layers on top
- Regularly add compost on top, preferrably at the change of every season, so organic material can seep into root channels created by cover crops
A suggested approach to improve clay soil quality and structure
To get the best out of the amount of effort and time you put into improving the quality and structure of your clay soil, here is a step by step guide to improving clay soil that may help. NOTE: use these steps as needed and if they make sense with your local micro-climate.
- Step 1: Work in wood chips, or rough compost as deep into your soil as you can. This is only possible if your clay is not too heavily compacted. You will never work the soil again once you have added these items in, so spend extra time on this
- Step 2: Add amendments like biochar, bonemeal or seaweed flakes to create additional materials for breakdown and for adding additonal nutrients into the ground
- Step 3: Plant a spring to summer cover crop like wheat or oats and cut down to use a green manure, but leaves roots untouched
- Step 4: Layer compost on top of the green manure before the winter planting of broad beans or legumes. When done, keep roots and the base of the plants in the ground and layer with more compost before you start your veggie planting
How to improve Sandy Soil
Why we want to improve sandy soil
Sandy soil poses a unique set of challenges to home gardeners, however, amending and improving sandy soil is significantly easier than clay soils. Why we want to improve sandy soil is because of three primary issues.
Firstly, sandy soils do not retain water or moisture very well. Because of this, plants growing in sandy soils run the risk of drying out very quickly. When windy days, which are common along the coastal areas where sandy soils are found, are added then plants can dehydrate incredibly quickly.
Secondly, which is somewhat dependant on point 1, is that sandy soils tend to have very poor nutritional value. Because moisture evaporates and drains very quickly, there is not much in terms of organic material to hold onto minerals and nutrients.
Thirdly, because of the lack of moisture, organic material, and nutrients, sandy soils lack soil life. Soil health and soil life is crucial to overall plant health and soil life needs the correct environment and resources to survive and multiply over time.
How can you improve sandy soil?
The single most effective way to increase the quality, water retention ability, nutrient update and create a thriving underground living environment is to add as much organic material as possible into sandy soils. Using crops that create significant underground biomass is incredibly effective as i binds together sand particles, which also provide a resource for nutrients to hold onto and release to the new plant roots.
Sandy soil gives you the ability to handle the material easily, which provides a great opportunity to significantly amend the soil before planting or using cover crops. Elements such as biochar, kelp, bonemeal, mulch, compost, and manure can be dig in quite deeply, which provides a great head start on building soil, in comparison to clay soil where this is mostly not possible.
What can you do to improve sandy soil?
- Make use of cover crops
- Use green manures where possible
- Regularly plant legumes
- Mix in lots of organic matter
- Dig trenches, add logs from cut trees, leaves, wood mulch to promote soil life and the breakdown of organic matter, increasing soil structure and add fertiliser
- Soil amendments such as kelp, bonemeal, leaf mulch, home made compost
A suggested approach to improve very sandy soil
- Step 1: In autumn/winter add in as much leaf mulch/fallen leaves into the areas and deeply turn the sand to get leaves as deep as possible underground
- Step 2: In spring sow a planting of oats or barley as a cover crop
- Step 3: In summer cut down as green manure and layer on top with some soil amendments and mulch
- Step 4: In winter, densely plant broad beans, which have deep, dense, nitrogen fixing roots
- Step 5: In spring cut broad bean plants just under the soil level and start your first planting
How to make your own compost at home
Why do you need to need to start making your own compost?
First and foremost, we want to reduce landfill waste and harmful emissions as much as possible by removing all food scraps from the bin. The more waste we can remove from our municiple bins and repurpose to be reused in the garden, the better.
Secondly, no matter your soil type, the biggest contributor to healthy and well structured soil is compost. Using compost is one of the most effective ways to feed your soil and living microorganisms in the soil. Home made compost is also clean compost – you know what when into it, which means you know what your food is going to be made up of. When you create your own compost at home you are closing the loop, leading to a more sustainable lifestyle. If you can repurpose the waste you create and leave the ground in a better state than you found it, then you are closing the consumption loop and contributing to a more sustainable lifestyle.
A big reason why you need to start making your own compost at home is Cost: you don’t need to keep buying compost in plastic bags to amend and feed your soil.
To find out more about your urban composting options then please take a look at this composting playlist – https://youtube.com/playlist?list=PL5vrlcVpXEyKXBInvHSGNftWj0h84fG
What is hot composting?
Hot composting is a very efficient way of composting organic materials and turning food and garden waste into quality compost. It is a composting process that makes use of oxygen and heat as the two primary activators that make this process so efficient and quick.
When to use hot composting?
The decision to use hot composting as your composting method of choice or not depends on a few things. You need to make sure that you have enough space to be able to make heaps of compost, space to efficiently turn the compost piles and then also have more than one pile at a time on the go. You should also consider using hot composting if you have lots of plants with seeds or diseased plants. The heat generated from this composting method is very effective as killing seeds and plant disease. In comparison, cold composting cannot tolerate seeds and diseased plants as those will thrive in the cold and dark environment. To be able to make hot composting work, you need to make sure you have enough brown, or carbon rich, material to be able to feed ongoing hot composting piles as they require a lot of brown material.
How to use hot composting
Once you have made the decision to use hot composting there are a few steps you need to follow to make sure that your compost pile works and thrives.
Firstly, and most importantly, you need to make sure that the compost is maintained at a temp between 55-65’C. Then,
- The pile needs to be a min of 1sqm and 1.5m heigh
- The content of the pile needs to be 25 to 30 parts carbon to one part nitrogen by weight (1 bucket greens to 2 buckets browns)
- Turn the whole pile every 2nd day (BERKLEY METHOD)
- Water the pile when needed to maintain sufficient moisture levels
What is required needed for hot composting?
Main benefits of hot composting
- Quick turnaround time
- Finer, lighter compost
Common issues faced with hot composting
- Running out of space
- Running out of raw materials
- Very labour intensive
- Requires careful planning and maintenance
- Can fail easily of proper balance of materials, moisture or heat is not maintained
Cold composting (specifically bokashi)
What is cold composting?
Cold composting is often referred to as the regular way of composting. It takes significantly longer to break down, but as a final product, has significantly more living organisms than hot compost. It uses an anaerobic environment (no oxygen) and microorganisms to break down materials slowly over time in a dark, cool environment.
When do you use cold composting
Cold composting is a great option in urban, residential areas where space is limited and busy city lives limit time availability. Due to the rapid expansion of the urban edge, plots are becoming smaller and neighbours closer and closer together. Because of this, composting can pose issues with smells and rodents. Cold composting, and specifically Bokashi, produces little to no smell and almost always uses anaerobic environments to break down organic material. This is also a great option for people with limited amount of raw material, such as kitchen waste, leaves, garden waste, paper, and more, to keep the composting system going.
How to use Bokashi at home
To get the best overview of how Bokashi works at home and how to get Bokashi to work for you, I strongly suggest you watch my detailed guide on how to do Bokashi composting within an urban environment. If you have any questions about Bokashi or how to use it at home then please drop me a comment on the below YouTube video.
What is required to make Bokashi work?
- Bokashi bran
- Bucket with a tap
- Food waste
- Soil factory to turn bokashi into finished compost
Main benefits of cold composting and bokashi
- uses little to no space
- does not smell or emit gasses
- requires minimal raw materials
- almost zero ongoing maintenance and manual input required
Common issues with cold composting and bokashi
- takes longer to reach final, usable compost, compared to hot composting
- some people do not like the smell of bokashi