Winter Gardening and Season Extension Techniques

If you get serious about winter gardens, I suggest you see Eliot Coleman’s books, The New Organic Grower and Four-Season Harvest. He lives and farms organically in Harborside, Maine. His books are excellent sources for all the details about winter gardening. In the meantime, here are a few guidelines based on my knowledge and experience.

The basic concept is to mesh the technology of climate modification using mini-tunnels with the biology of the crops that are suitable. Of course you can get fancy with heating and lighting, etc and grow almost anything the year around. What I am referring to for our area simply allows you to grow a few cold-weather crops longer into the fall/winter and to start some spring crops earlier than normal. In this area, I have experience with lettuce, radishes, spinach, mache, onions, broccoli, carrots, and potatoes. I suggest you try some late fall sowing, under cover (described below and referred to as mini-tunnels) with these crops and then sow again in late January. You won’t need the tunnels in our climate until November. If you try to use them too early in the fall or too late in the spring, they will heat up too much with the plastic cover in place.

It is not difficult to set up a small bed for growing a few crops. Here is the design and system for a mini-tunnel that works in this area. Supplies needed to make a 4x25-foot bed include:

1. 6 mil clear plastic. It comes in 10 and 20-foot wide strips. I buy it in a 100-foot roll.

2. 18 reinforcing rods, each piece 24 inches long, 3/8-inch diameter.

3. 9 pieces of ¾- inch (inside diameter) plastic tubing, each piece 7.0 feet long. You can buy it in rolls and cut it. This 7.0-foot length of tubing is designed for a bed that is 4 feet in width.

4. Boards, bricks, rocks, and straw to hold down the plastic. Maintaining the tunnel in strong winds is the biggest problem, and anchoring the plastic is the key.

5. Optional, but very desirable: Heat absorbing material inside the tunnel. I use one-gallon glass and plastic jugs, painted black, and filled with paramagnetic rock. It works great. The jugs pick up a lot of heat during the sunny days and dissipate it into the soil and tunnel at night. Set the jugs a couple inches deep into the soil. I use about 15 jugs for my 100-square foot garden bed. The magnetic energy absorbed by the paramagnetic rock is also used by the plants for increased growth.

The construction is easy:

1. Lay out exactly where the 18 reinforcing rods will be placed. Use a string to line them up on each side of the bed. Be sure they are the same distance apart across the beds. Try for 4-foot spacing. Pound the reinforcing rods about 18 inches deep into the soil on each side of the beds. That leaves about 6 inches sticking out to “hook” the plastic tubes. 3-foot spacing of the rods, along the sides of the bed works fine.

2. Place the 7.0-foot plastic tubes over the rods, to make the semi-circle frame.

3. Adjust the tubes so you have a uniform height and shape for all the tubes. This will help to provide a uniform surface with the plastic cover.

4. Cut the 10-foot wide plastic to desired length. Allow about 5 extra feet on each end for good anchoring.

5. If you are doing this alone, choose a calm day to install the plastic. Lay the plastic over the tubes. Anchor the windward side so that no wind can get under the plastic! This is important! First lay down some boards, bricks, rocks, etc. on the plastic. 2x6 planks work very well. Then cover that all up with a heavy layer of mulch or straw (wood chips are fine). Don’t leave any place for the wind to get under the plastic. Anchor the ends in a similar manner.

6. Remember that you are going to periodically open this up to work in the garden bed. So on the lee side (East, if you have N-S rows), I just anchor the plastic with 2x6 planks, weighed down with a few cement blocks. It works well to have a 4-6-inch layer of straw down in the pathway on the lee (east) side also. It will help in the winter when the soil is wet and you want to open the tunnel.

According to Eliot Coleman, a tunnel of this type will effectively move you to a climate that is about 1.5 hardiness zones to the south. For us that means a climate like mid-Louisiana. The real advantage is the ability to get started at least a month earlier in the spring. I use the mini-tunnel to start early seeds for lettuce, spinach, onions, cabbage, broccoli, and tomatoes. Some of the plants can be left in the tunnel and others can be transplanted to other beds when the time is appropriate.

Transplanting, Thinning and Mycorrhizae

Thinning: We survived the heat and drought and now is the time to enjoy fall vegetable gardening. Hopefully your crops are growing and you are siting back and waiting....OOOOps! Not quite. I see a lot of gardens where carrot, beet, radish, spinach, lettuce, and turnip production is not good, simply because the crop was not thinned. The seeds are small and planted too close together, and then the plants are not thinned as required.

For the most part, the sooner you thin the better. Give the plants space to grow. I plant in 4-foot wide beds so I have blocks of vegetables. The number of rows is determined by the unique spacing required for each vegetable. In “How to Grow More Vegetables” by John Jeavons, there are spacing tables. This is an excellent guide, but I usually increase the spacing by an inch or two for the fall plantings. I want them to grow as fast as possible, and a little more space helps to get them to the market or table sooner. Here are a few spacings (in inches) that are good for the fall: Carrots - 4, Beets - 5, Radishes - 3, Spinach - 9, Turnips - 6, Lettuce - 6-12 (depends on variety).

Transplanting: Sometime I sow seeds very close together, with the idea that the small plants will all get transplanted. This works fine with beets, spinach and lettuce, and can be done at the two-leaf stage, when the plants are only an inch tall. Beets can be transplanted after they are several inches tall, but not as easily. Carrots can be transplanted but

the job requires a lot of careful placement and patience. With pelleted carrot seed, like I used this fall, the spacing is more uniform, and so little thinning or transplanting is needed.

Mycorrhizal Fungi: These are the good guys and you want them on your team. Over 90

percent of the plants known use them in a mutually beneficial manner. They are not visible with the naked eye, but are attached to plant roots. In a real sense they are root extensions -- bringing water and nutrients into the plant. A thimble full of healthy soil can contain several miles of fungal filaments.

An acre of healthy top soil can have 2500 pounds of mycorrhizal fungi. This is good organic matter.

Soil Tilth and Mycorrhizae Soil tilth is about good soil structure -- soils that work easily, don’t crust, and take in water and air. Soils with good tilth are said to be well-aggregated, with soil particles joined together in stable clusters.

A few years ago, A USDA microbiologist Sara Wright named the glue that holds the soil aggregates together. She called it “glomalin,” from the Glomales group of mycorrhizal fungi. This gooey protein comes from the tiny fungi filaments. Its a sticky glue that helps your soil in many ways.

Do you have the Glomales fungi species in your soil? Maybe, maybe not. They occur naturally in most undisturbed soil systems. But they can also be destroyed by some fungicides, and can be reduced by high rates of available phosphorus. If you are concerned your garden is lacking in mycorrhizae, go on line and order some. If you want some recommended sources, please contact me.

It goes without saying, but the organic route is an

excellent way to keep the good guys (Mycorrhizae) on your team.

Fall Cover Crops

Time to Plant Beets and Carrots

The August heat and dry weather have made gardening a real challenge. Don’t be discouraged. As the weather gets a bit cooler, it will be time for rejuvenating the garden. Fall gardening can be easy and enjoyable. I am getting excited about planting my fall carrots and beets. They do well and are easy to grow. I will be starting mine the last week of August. This year I am using pelleted carrot seed. Its basically an organic coating on each individual seed. The value of pelleting lies in the ease of sowing the seeds in a much more uniform distribution, thus minimizing the thinning process. The coating dissolves quickly when placed in the soil. Pelleted seed is about the size of turnip seed.

If No Fall Veggies -- Plant a Cover Crop

We know it is important to build a healthy soil i.e., a soil that is alive, full of microbes, adequate minerals, and a reasonable organic matter level. Cover crops can be useful for reaching these goals. There are many choices. For simplicity in the fall, I have settled on two crops --Oats and Austrian Winter Peas. The peas have the advantage of

surviving the cold winters, growing again in the spring and fixing nitrogen in the soil. The oats has the advantage of quickly covering the site, and dying in the winter, thus leaving a heavy mulch cover that helps to curtail the development of winter weeds. I plant my early spring crops where I have the oats.

Oats and peas can be planted together, but the timing of the combination planting is tricky. If you plant the combination too early, the oats smothers out the peas. If you plant the oats too late, it does not make a dense stand, and the effectiveness as a mulch is minimal.

I use oats and peas, separately. By planting in early September, you should have a stand that looks like the peas (on the left) and the oats (on the right), by early November. They make a pretty sight.

Both oats and the peas are available locally, but generally only in 50 pound bags. I buy a bag and repackage for small garden plots. If you want some oats or peas, or information on how to sow, send me an email. I would be pleased to assist. Once you try these crops you will be hooked.

August -- the time for Fall Gardening

PLAN AHEAD: Many summer vegetables are in full swing now, and it easy to forget that late August is a good time to plant some fall crops. Although the bugs can be a small problem in August plantings, I thoroughly enjoy the fall crops. Carrots and beets are my favorites. Fall carrots are generally superb and even sweeter than those grown in the spring/summer. Don’t forget about radishes, turnips, broccoli, kale, spinach, cabbage, etc. They will all do well.

If you are not planting a fall vegetable garden, then I recommend you plant a fall cover crop. This is an excellent step to help build a healthy soil, and to suppress winter weeds. It is very easy to do.

LEARNING MORE: Each year I do a few trials of new vegetable varieties. I have a nice loose, healthy soil and so this year I tried five varieties of carrots. The old standby Danvers did very well, as did Napoli and Mokum. I was not pleased with the carrot called Atomic Red. I really liked the flavor, smoothness, and length of a carrot called Sugarsnap, but it was the only one with a minor insect problem. I will try it again in August.

NEXT COURSE: I will be teaching an Organic Gardening course on August 14 and August 21. I do the summer course for those who want to do fall vegetable gardens and fall cover crops, or to get an early start for next spring. If you are interested please send me an email for the class announcement, and then get registered. I limit each class to 16 people, so they are likely to fill.

RAISED BEDS: As I write this we are getting what will be more than 7 inches of rain in the past 10 days. Although excess rain is rarely a problem in the summer, I have seen several gardens with problems, i.e. standing water. Raised beds have many advantages, and right now one of those advantages is very evident. My garden has not had any problem with the excessive rain. Raised beds saved the day.

Soil is a Living Organism

A healthy soil is a living system, replete with important, “good guy” organisms. Whether it is vegetables, fruit trees, flowers, or forests, a community of living organisms (microbes) will exist. This soil food web consists of bacteria, fungi, nematodes, arthropods, protozota, earthworms, insects, and small vertebrates.

These organisms serve many functions:

1. They decompose organic compounds, including plant residue, manure, and some pesticides.

2. They transform the minerals into the proper forms for uptake by the plants. Think of them as the digestive system (stomach) for the plants. Its like this -- the microbes are the servants but they eat first, then the plants are served.

3. They fix nitrogen, enhance soil porosity, and prey on crop pests.

4. They hold nutrients in reserve, improve soil structure, increase water holding capacity, and increase carbon sequestration

5 Earthworms can actually turn over the top six inches of soil in 10 to 20 years, often moving large amounts of soil up from the lower strata and organic matter down to deeper layers.

These advantages and more are strong reasons for gardeners and farmers to go organic. Strong pesticides and chemical fertilizers impact the soil organisms negatively and work against the development of a healthy soil.

The numbers of the various soil organisms in a soil will depend on the crop and past

management practices. Bacteria and fungi will generally make up the bulk of the organisms. Forest soils have more organisms than prairie soils, followed by agriculture soils. In agriculture and garden soils, the

numbers increase with increased organic

matter, minimum tillage, and with the use of organic amendments.

The numbers of living organisms in healthy soils is astounding. A teaspoon of agriculture soil can contain up to 1 billion

bacteria, several yards of fungi, several thousand protozoa, and 20 nematodes. Add to that 100 arthropods and thirty

earthworms per square foot, and you have an acre of soil with the living biomass that weighs a ton or more.

Tomato Time: Those 15 inch tall tomatoes (in 2 gallon pots), that I planted in early May are growing at phenomenal rates. They are now 5 feet tall, and loaded with tomatoes. I am trying a new cherry tomato called “Riesentraube.” It looks like it will be PROLIFIC. Here on June 17, I estimate 600 tomatoes already on the plant. Will keep you posted.

Compost/Organic Matter Issues

Using more compost than necessary can create gardening problems. Depending on the compost origin and amounts used, soil minerals can actually become excessive and unbalanced. Correct ratios of minerals in the soil are important. Practices like “Lasagna” and/or “Square-Foot” gardening call for large amounts of organic matter. These are practices that will generally not yield vegetables that are dense in nutrients. With an excess of soil nitrogen, you often get excessive vegetative growth and poor fruit and seed development. Excessive use of compost can also raise the P, K, and Ca levels to more than are needed. Remember, if you keep a healthy (non-chemical) soil, it will be moving in the direction of increasing the organic matter on its own, through all the natural processes.

I have dealt with these issues with gardeners this past month. The AR Soil Lab would not even do a soil test on “soil” sent in from one Square-Foot gardener. The Soil Lab reply was, “send us some mineral soil, not just the soil mulch.” This does not surprise me. The recommended Square-Foot gardening “soil” material is all derived from various kinds of organic matter.

I have looked at many materials for advice on application of compost. The book, How to Grow More Vegetables, by John Jeavons is certainly one of the best for organic/sustainable gardening approaches. John recommends, “a maximum maintenance dressing of ½ inch of compost should be added to the soil before the crop per 4-month growing season.” That is equivalent to 4 cubic feet per 100 square feet of garden bed. I only recommend using high quality, mature compost. Cheap compost that is not fully decomposed is generally not a bargain.

For new beds in our typical NW Arkansas soils (where soil depths can vary from 6 to 20 inches), I recommend that you begin by double digging. In such cases, I recommend that you put 2/3 inch of compost into the lower layer and 1/3 inch on the surface. That equates to 40 and 20 gallons on each respective layer per 100 square feet. So, as you begin, 1 cubic yard of soil is enough for more than 300 square feet.

Tomato Time Hopefully, you have set your tomatoes out and they are doing okay. If you buy plants in tiny pots, I always recommend that you first move them to larger pots. See they picture below. Both plants are of same age (7 weeks), but note the huge (more than doubled-size difference), when the one plant on the left was moved to a 2-gallon pot when the plant was 6 inches tall.

Raised Beds and Double-Digging

You can follow organic gardening practices with or without raised beds. The advantages of raised beds are well worth the extra effort, especially in wet and/or cool springs. The biggest advantages are that they are better drained, better aerated, and warm up more quickly in the spring. If you have a wet and/or cool spring, like we have this year, the raised beds are very nice. Once formed, they also make planting, weeding and harvesting just a little easier.

When you think “raised beds” you might think in terms of building frames and bringing in extra soil. That is one option, but you can easily have raised beds without sideboards, simply by using the soil you have on the site. Whether to bring in extra top soil is usually determined by the depth of the top soil you have in place. With topsoil that is 12-18 deep, you can build 12-15 inch raised beds easily without bringing in soil.

I advise building raised beds in the process of double-digging the garden. I have shown many times, how double-digging jump starts the soil to becoming biologically active and healthy. There is no room for details here, but see Jeavons, “How to Grow More Vegetables” for details on double-digging.

Steve Moore, at University of North Carolina, described another value of double-digging where he compared old-style practices and double-dug beds, where he was teaching in South Africa. In the test with spinach, a heat wave occurred soon after establishment. In the old-style (conventional) plots, 99 percent of the plants died. In the double-dug plots, 1 percent of the plants died. Plants respond accordingly to the environment that is provided.

The 15- inch raised beds shown above were established in September and seeded with a cover crop of Austrian winter peas and oats. In reality, you can double-dig and build raised beds anytime of the year. Be sure moisture content is adequate, but not too wet, if you try to do it in mid-summer.

The GROW BIOINTENSIVE® approach of John Jeavons, which includes double-digging, is not something new. It is used around the world. The Manor House Agriculture Center in Kenya has graduated 400 trainers over the past 25 years, and the practices are being used by millions around the world. This is a significant movement. The World Bank, UN-FAO, and others have recently stated that small-scale farming may hold the solution to the world hunger problem. It is also true, that our continued conventional path is damaging to the environment and not sustainable.

Each of us has the ability to be part of the solution to the world hunger challenges in the world today. We just need to start! If it is a question about how to get started with growing a few vegetables, I am always available to help.