Organic Landscape Design

By David Braden

When people think of a vegetable garden this is what they think about:

This is a beautiful garden but, it was tilled and the gardener has been diligent about weeding and watering.  In addition to the time that the gardener has spent, this garden is actively depleting its soil.  In order to make this garden productive year after year, the gardener will have to incorporate supplemental nurtrients.  Those nutrients will either be manufactured using fossil fuels, or they will be created by composting organic matter taken from some other soil - depleting that soil.

This is a Tilled, Weeded, Hand Watered, No Mulch Gardening System.  It is time honored and there is a lot of information about how to grow quality crops in this system.  However, the system depletes the soil over time and if the gardener is not diligent the garden will look like the following garden.

This garden bed was sheet mulched last year and produced a bumper crop of tomatoes, beans and squashes.  From the lush growth and dark green color of the plants you can tell that the soil is still healthy and fertile.  However, the owner of this garden has not taken the time to accept the gift of the mulch that has volunteered here and therefore the volunteer mulch is overtaking the plants they intended to grow.

This is a No Till, No Weeding, No Mulch, Drip Irrigated Gardening System, and the reason people think gardening is too much work.  To keep all the weeds out of that bed would require working as hard as the person with the garden shown above - and depleting your soil - just like they are.

This bed is directly across from the one above.  Don Studinski planted potatoes in this bed and in the middle of June it was overrun with bind weed.  Don and I pulled the bind weed as "volunteer mulch".  We then put a 1/2 inch of manure on the west half of the bed as an experiment to see if the manure would help or hurt the potatoes.  Next, we spread newspapers over the entire bed (a couple of "sections" deep) - up to the stems of the potatoes - and except for some chives growing in the foreground.  Next we put another 1/2 inch of manure on the west half of the bed and then covered the entire bed with 8 inches of mulch that had just been cut off the south end of the church property (yes, weed seeds and all).

This picture was taken July 5, nearly three weeks later.  As you can see, there are still no weeds coming up through the newspaper.  If any thing, the manure on the west half benefited the potatoes.

This is a NO WEED, No Water, No Till, DEEP MULCHED, Drip Irrigated Gardening System,

If you are not feeding your soil you are depleting it.  The food available for your soil can be measured as average depth of mulch and if we keep a relatively uniform level of mulch we will be maintaining a stable and balanced ecosystem of soil organisms.

The Deep Mulch approach is emulating the way a forest builds soil - a constant leaf fall creating a seasonally varied layer of mulch on the forest floor.

I am working at combining that with the way a grass land builds soil - a relationship between grass root and grass leaf.  When the grass grows tall it grows more root and when the buffalo eats the grass it sheds root.  The root that is shed begins to decompose and will hold the water the grass will need to grow again next spring.

In our case, we cut what ever grows on the area not yet sheet mulched when it has reached a maximum height to encourage grasses adapted to this climate.  Those grasses will build the soil in the open areas just like they do in any other grass land and the grass that we cut is available to deep mulch our gardens.

A successful gardener must choose the system that they are going to use.  The permaculture gardens we are involved in are designed to demonstrate the deep mulch system and we are not going to be importing expensive nutrients that our soils can produce for us.

The 2011 Experiments

In 2011 we have beds at the Applewood Permaculture Institute that have not been tilled for 7 years.  After the initial sheet mulch, these beds have had various levels of success, although, the fertility seems to be good.  Last year, I tried adding dry hay on top of the drip system.   There was no decomposition in the mulch and this springs the plant growth indicated a shortage of nitrogen.  In spite of the experience of Ruth Stout, these beds are still heavy clay, even after the years of deep mulching.

There are six key hole beds in the experiment. 

Bed 1 had carrots in the outside ring, a partial deep mulch in the middle ring, and chard in the center.  The carrots and chard did well until the voles found them, but the beans were eaten off as soon as they sprouted in two different plantings.

Bed 2 was tomatoes, basil and cucumbers.  Mulch was added after planting. The tomatoes and basil did acceptable (until our resident deer ate every green tomato) but the cucumbers eventually suffered insect attack.  Manure was added as a top layer late in the season.

Beds 3, 4, and 6 were mulched after planting but the plants did not thrive.  Some manure was added toward the middle of the season.

Bed 5 was planted to corn, beans and squash with the corn in the middle planted in the soil and the beans and squash planted in the previous year's mulch.  The corn grew well.  The beans and squash did not thrive and were eaten by insects.  Additional mulch and another layer of manure where added in August.

This year I changed things in the following way:

Bed 1 was given a new sheet mulch with wood chips the second week of June.  The beans and squashes are thriving as we expect in a new sheet mulch.

Bed 2 had the mulch removed and added to Bed 3.  I planted carrots and they are doing fine.  I intend to do a complete sheet mulch of Bed 2 after hard frost.

Bed 3 was surrounded with deer fence to become the permanent tomato bed.  It had two layers of last year's mulch with two layers of manure mixed in as it was transfered from Bed 2.  I planted asparagus, basil and tomatoes by making a hole in the mulch, placing the plant on the ground and then adding a little soil to fill the hole, I planted cucumbers in the top of the mulch.  This bed was not doing as well as the new sheet mulch at 14030.  I added another layer of manure and then about 8 inches to a foot of new cut hay, and soaked the mulch well.  The bed is now thriving and on its way to catching up with the new sheet mulches.

Bed 4 was in garlic from last fall.  I planted beans, pumpkins, and cucumbers in the outside ring.  The beans were eaten off as they sprouted, the rest were not thriving.  I harvested the garlic the first of July and deep mulched around the pumpkins and cucumbers with fresh cut hay and soaked the new mulch.  The remaining plants continue to fail to thrive.

Bed 5 was planted to beans, pumpkins and a melon.  The beans were eaten off at sprouting and the remaining plants failed to thrive.  I added a layer of manure and replanted the beans.  The pumpkins have responded positively.  The new beans have just sprouted but look much better.

Bed 6 was planted with the 3 sisters.  The corn was doing ok.  The beans were eaten off at sprouting.  The squashes were stunted.  I added a layer of manure and replanted the beans.  Some of the squashes are responding to the extra nitrogen.  The beans were eaten off at sprouting a second time.

Beds 5 and 6 are next to each other and have had similar treatments.  I cannot explain the difference in response to the addition of manure.

LESSONS

I have been assuming that seeds will be happiest if planted in the soil.  Based on that assumption, I have been thinking of mulching as adding food for the soil organisms after the plants have sprouted.  We say that, after the first year, all we have to do is plant, mulch, harvest.  However, if seeds are just as happy planted in the top of the mulch, which it seems is the case, then that is even easier.  We can mulch, plant, harvest.

I think what is happening is that the heavy clay is not allowing sufficient gas exchange in the root zone for plants like beans and squash.  That is one of the things you get with tilling, but, once the organic matter is burned, and the clay gets wet, you have to start again, adding organic matter and tilling . . . every year.  We get plenty of gas exchange and nutrient availability in a new sheet mulch, which is why we get such spectacular results.  If we plan on planting in the top of the mulch, instead of the soil, we can add new layers of mulch and manure anytime after hard frost and be ready to plant whenever the weather cooperates.

The one advantage of planting in the soil, and then tucking mulch in and around your growing plants later, is that we do not need to find the soil/compost that is necessary, when we plant in the mulch, to keep seeds moist until germination.  What I started doing this year to plant in my new sheet mulches, was to dig out the pathways around my old beds and replace the soil with wood chips.  That effectively makes the existing beds raised beds, and I have really good soil for planting my seeds in the mulch, that is not doing much good as pathway, anyway.  That is more work than just pulling back the mulch and putting the seed in the ground, but, maybe comparable to then having to go back and add mulch without damaging the plants.

A final thought based on mulching on top of the drip line:  The three macro elements to decomposition, as in a compost pile, are carbon and nitrogen in balance and moisture.  Although incredibly efficient, the drip systems will not always maintain an adequate moisture level in the mulch for our soil organisms to produce a continuing flow of nutrients.  Perhaps we can turn down the drip system a little and include a top watering of the mulch as a part of our gardening routines, in order to ensure that our gardening partners have adequate moisture to do their work.

Stay tuned for more results.