Cathie Draine, writer
This is a general information page where local gardeners share their information and experience. We encourage area gardeners to send their experiences. Especially welcome are the titles of books, magazine articles and Web links that persons have found helpful. We will post it with the writer's name and affiliation - Master Gardener, garden club member, 4-H member, home hobby gardener, etc.
Fast facts about compost and mulch…
Cathie Draine, Pennington County MG
Let’s look at what they have in common:
Both can be used to cover the soil (to retain moisture.)
- Both can be not only beneficial for the soil but also helpful for the gardener.
Let’s look at how they are different:
- Compost is always comprised of organic material. (By definition that means something that has been alive – grass, wood chips, paper (trees), leaves, fresh plants, fruits, veggies, feathers, hair….)
- Mulch can contain organic material, but rocks and plastic are sometimes used for mulch.
Let’s look at how they are used:
- Mulches are always placed on top of the soil. They may biodegrade in time (ex. woodchips) but they are always used on the soil surface.
- Compost material can be used as mulch on the top of the soil. It is recommended as a soil amendment (to be worked into the soil).
Let’s give some specific examples:
- To establish a new garden bed, lay 12-18” of either organic mulch or compost on the intended bed in the fall, water it well until the ground freezes and plant directly into that undisturbed material in the spring.
- In an established veg or flowerbed, add 2-4” of either compost or mulch around established plants and between the rows of row crops. Do this after the spring weeding and again just as the gardenseason is ending.
- Keep 2-4” of either on the surface of your soil year round.
- When preparing your soil to get ready to plant in the spring, work approximately 4” of compost into the soil. After the seeds are in or the plants set out, top dress around the rows or plants with mulch.
Hints to remember:
- Trees and shrubs grow in fungus dominant soil. Therefore, mulch with woodchips. (Fungi have the capability to digest or break down wood.)
- Flower and vegetable gardens and lawns grow in bacteria dominant soil. Therefore, mulch with compost. (Most organic mulches are created by the action of bacteria).
Fast facts about tilling…or not
Cathie Draine, Pennington County MG
Let’s review a little history:
1. For thousands of years seeds were placed in the ground by making a little hole with a planting stick and dropping the seed into the soil.
2. Fields rarely were barren (lacking anything growing on it).
3. Fields were ‘renewed’ by plant debris and animal manures.
4. Several persons in the early 1800s in America devised plows with shaped moldboards that would reduce friction as they cut into the soil.
5. Rather quickly, the plow was mechanized.
Where’s the problem?
- As is frequently (and sometimes unhappily) the case, a technique or tool that has been developed for large-scale agriculture is ‘refitted’ for the home garden – thus, we have the gas-powered home garden tiller.
- Using a tiller, a gardener can turn the soil of a large garden in a short period of time. (The advantage is for the operator. There is NO advantage for the garden soil.)
- The weight of the tiller compresses the soil making it difficult for the soil to “breathe”.
- The blades of the tiller destroy the soil structure.
- The cutting and churning action destroys microbial communities as well as killing soil organisms.
- The tillers use gas and emit CO2 – neither of which is valuable for the garden nor the environment.
- They are expensive.
What are the options if you choose not to use a tiller?
- Keep the garden soil well mulched and undisturbed.
- Have defined paths in the garden. Stay on those and out of and off the garden beds.
- Laying down a cover 4-6” deep of mulch and compost in the fall will ready the garden for spring planting.
- If you must dig, use an earth fork.
There is good science that suggests that the weight of heavy machinery on the soil is highly destructive – as a result, many home gardeners are discovering the ease and success of non-tilling.
What is the weed cloth supposed to do?
1. According to the manufacturer this is supposed to keep the soil weed-free.
2. It is implied that the weed cloth will also keep mulch looking tidy.
What actually happens?
1. If the weed barrier is plastic, it will greatly and negatively reduce the amount of air and water that needs to enter and leave the soil.
2. The microorganisms in the soil die because of the lack of oxygen. The soil beneath the plastic becomes anaerobic.
3. Anaerobic soil can be devastating to plants that might be planted in the weed barrier area.
What about weed control?
1.Most weed seeds need sunlight to germinate. In that sense the weed barrier is effective.
2. Many, many weed seeds are airborne and land in the mulch on top of the barrier and take root there.
3. If the weed roots penetrate the fabric (or plastic) and they can, it becomes a real mess.
If weed barrier fabric (or plastic) doesn't work to control weeds, what does?
1. Mulch. This works because as the mulch biodegrades over time, it feeds the soil.
2. Weeds generally don't like humus-rich soil. If they sprout, the roots are generally weak and they are easily hand-pilled.
Why was weed barrier cloth/plastic ever thought to be a good idea?
1. It is an example of a process originally used in nurseries, windbreaks etc. that got moved into the area of home gardening/landscaping.
2. Save your money. Mulch your plants.