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Stretching the production season of many fruits and vegetable crops has the potential to dramatically affect overall profitability for farmers or in our case production since most of us aren’t selling. The basic philosophy behind each practice noted is to maintain optimum growing conditions over a longer season than that provided by nature. Biologically intensive farming dates back to 4,000 years ago to China; 2,000 years ago in Greece and 1,000 years ago in Latin America Practiced in Europe during the 1800s and early 1900s, French intensive techniques were developed in the 1700s and 1800s outside Paris. During the winter ,glass jars were placed over seedlings to give them an early start These methods are not however intended to drastically modify or control climatic conditions in the field.

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The nice thing is that many of the purchased materials can be reused during a single season to allow double and in some cases even triple cropping. Some are even long term purchases that can be used for year. In general more intensive techniques afford a greater degree of control.

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Season extenders fit the needs of a management strategy by trapping heat energy to provide some frost protection. The season extender provided wind protection for the crop and captures the heat energy which together create favorable microclimates for plan growth. An additional benefit is a reduction in evaporation of soil moister, thus conserving that natural resource Disease pressure is also reduced in situations where the foliage is kept dry – tomatoes Insect and disease control is enhanced by the exclusion of insects from the crop under the season extender.

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Location and Cultural considerations are the first place to start. You can actually extend your season or get more out of the garden first by paying attention to location and cultural requirements. One of the easiest is to make sure you are selecting cultivars that can handle the cold and or the heat.

For most of us, the winter harvest should focus on “chilling-resistant” Vegetables.

Planning ahead is important as seed rakes are often put away come August and therefore seed is not readily available. Probably more important than seed scarcity is That most folks are unfamiliar with some of the crops that can be grown in the colder months.

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In most of the continental US, our normal weather can be harsher and more

changeable than where these crops we are growing originated. We need to be able to

moderate the winter weather to be able to harvest even the hardiest of winter foods.

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The Color of the mulch has a great deal to do with it’s ability to warm the soil underneath. For Example black plastic can increase soil temp at a 2 inch depth by 5 degrees over bare soil, where as clear plastic can increase the temperature by 8 to 14 degrees.

The use of plastic mulch in vegetable gardens has many advantages and also a few disadvantages. Gardeners may be confused about whether to use black, clear or colored plastic. The Next few slides will cover some of the differences in benefits and disadvantages.

The most widely used plastic mulch is black. Black plastic prevents weed growth and clear plastic does not, requiring herbicide use or fumigation to control weeds. Weed growth under colored mulches depends on the degree of opacity of the mulch.

The most widely studied color is red. Some studies have shown increased and/or early harvest in crops including tomato, pepper, melon, and zucchini, while others have shown no significant difference. One study compared red mulches from five different manufacturers. The mulches varied in opacity and longevity of color and included one biodegradable product. Increased yield was obtained in the products that were opaque and did not fade during the growing season. The biodegradable product faded as it broke down (broken down by sunlight) and did not increase yields. In one study, it appeared that red mulch may reduce severity of early blight of tomato. Using red mulch may increase plant growth and yield, and opaque products will have the same additional advantages as black mulch.

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Reflective mulches have also been receiving some attention and they may be helpful in reducing aphid problems by confusing them. Some colored mulches attracted the green peach aphid (pest of vegetable crops and virus vector), especially yellow mulch. Yellow also attracted striped and spotted cucumber beetles. Yellow traps are often used to monitor insect populations because it attracts them, so yellow mulch is being considered as an option for trapping insects on the edges of a field, much like trap cropping.

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The plasticulture system has three main parts — plastic mulch, raised beds, and a drip irrigation system that runs underneath the plastic. Drip irrigation lines deliver both water and liquid fertilizer directly to the plant’s root zone.

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This is a photo of a French farmer in the late 1800’s

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Cloche is French for a bell jar or dish cover. In a garden a cloche is a temporary structure which serves as a mini- greenhouse set directly into the garden

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You can now buy easier to use cloches though various garden catalogs – less breakage than the old glass jars.

They continue to help gardeners. This commercially available Pop-up Cloche helps homeowners to deal with sudden changes in the weather . It is an instant remedy to unexpected frosts, wind, birds and pest attacks in the garden!

Simply pop open the heavy duty polyethylene cloche and cover individual plants, trays of seedlings, pot plants and new transplants or use to warm the soil prior to planting and bring on your plants early or late in the season – we’re sure plenty of other potential uses for this 'quick cloche' will pop into your head!

This grow cloche is available in three sizes, features ventilation holes to prevent excess humidity and allow essential air flow and comes complete with four ground anchoring pegs - needless to say, this cloche is about as portable as it gets and is available on line from Harrods Horticulture

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Use plastic milk jugs with the bottoms cut out to protect small, individual plants from cold. These will generally last a season or two, but need to be replaced since they become brittle in sunlight over time.

Certainly cheap enough

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These are biodegradable, again you can find in many catalogs.

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My favorite of these would have to be the Wall of Water. Walls of Water are useful devices to extend the growing season for tomatoes, peppers, eggplant and other warm-season vegetables.

The channels of water in the sides of the plastic cone absorb heat from the sun during the day and radiate it back to the plant growing in the cone at night.

This provides an even greater benefit than simple frost-protection covers that do not store heat..

Plants grown without the benefit of a night heat source will remain set back for weeks, even after the weather finally turns warm.

Until night temperatures are consistently above 55 degrees, the Walls of Water are providing an appreciable benefit to your tomatoes, and you should consider letting them remain around your plants. Also be careful not to overwater plants, as cold and wet conditions are worse than cold and moist. Carefully dig down around plants to check soil moisture before watering.

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Here we start to cross over into what I would refer to as a low tunnels or even a row cover.

Make temporary cloches by arching fiberglass materials over the row or bed and sticking it into the ground on each side

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Lets go back to what I think of as an easy inexpensive season extender.

Floating row covers are large sheets of very lightweight spun bonded polyester or spun bonded polypropylene that is placed over the crop like a blanket. The material resembles the inner facing used in sewing garments. The fabric- like material is made up of randomly arranged fibers that are bonded together with heat and pressure. The resulting material is porous and allows moisture, air, and light to pass through the cover for plant growth.

Floating row covers are usually applied to the field early in the season and are pushed up as the crop grows. They do not require any support other than the crop on which they are placed. They can be used in combination with plastic mulches to further enhance the micro- climate for plants like tomatoes, peppers, and cucurbits.

However, floating row covers can do damage to crops like tomatoes and peppers by rubbing against the crop as the row covers undulate in the wind. When used alone, the floating row cover will only provide a few degrees of protection against frost or freezing temperatures. For this reason, some of the cooler season crops may benefit more from the row cover. Crops like carrots, beets, lettuce, spinach, and even potatoes can take great advantage of those few degrees at night and the overall warmer temperature in the day to produce a crop 10 to 14 days earlier than by regular production methods. Covers must be managed carefully; they may need to be pulled off in midday

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Low tunnels cover individual crop rows with a poly cover supported by wire hoops stuck into the ground. The hoops are usually constructed from galvanized number 9 wire which is used to support a 1.1 mil polyethylene cover. The length of the wire is usually 70 to 80 inches. When bent to form a hoop over the crop row, the wire makes a tunnel that is about 18 inches tall. Tunnel height of up to 30 inches can be used with crops that develop large, vegetative canopies early in the spring, i.e., summer squash. The poly covering is then placed over the hoops to create the low tunnel. These tunnels are most often used in combination with plastic mulch which will control weeds and help to warm the soil. The tunnels are installed after the crop has been transplanted in the rows and are usually left in place for 3 to 6 weeks.

One of the major management concerns is the difficulty of ventilating the tunnels. To allow some ventilation, many manufacturers also make a 1.1 mil poly that is slitted. The slits allow a certain amount of natural ventilation to occur. This helps to regulate the temperature and humidity on sunny days when the heat inside the low tunnel can get high enough to damage the crop. If nonslitted plastic is used, the cover must be removed or cut to provide adequate ventilation to reduce high temperature and humidity. Manual slitting of the cover can take a great deal of time and be quite costly if the poly is ruined. The fact that the sides of these tunnels are secured by covering them with soil adds to the difficulty of uncovering the plants.

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If the beds are enclosed with lumber, attach brackets to the inside edges of the boxes or sink short pieces of pipe with a larger inside diameter along the sides to hold arches that can be made from flexible pvc piping..

The arches can be used to support old sheets, shade cloth, Reemay or similar products to ward off frost if they are fastened more securely to the raised bed frames.

When this structure is no longer needed, simply remove the covering and poly pipe ribs and store them until the following season.

Note that in the lower picture, the ends would have to be covered also to provide an insect barrier.

Various materials can be used to physically block or repel insects and keep them from damaging plants. Lightweight floating row covers can be used to cover some crops to protect them. Plants must be covered when they are planted, and edges of the cover must be covered with soil or something to keep insects out. If the crop requires pollination the cover must be removed when flowering begins. A framework can be used, or the row cover can be loosely laid over the plants – just leave enough extra material so that the plants can lift the row cover as they grow.

Soil on the edges of the cover helps to prevent air leakage on cold nights and holds the nonporous poly in place during high winds in the spring.

Chenilles (caterpillars) French 36 inches wide by 18 inches tall fields of them look like large chenille bedspreads

The new ag fabrics solve the venting problem by being porous to air and thus are reasonably self venting

Not recommended for gardeners north of zone 7. this design would be risky for overwinter use since wire-framed structures would not hold up where heavy snow was a constant threat

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Simplest, most flexible and most successful low-tech tool for modifying the garden climate.

It is basically a box with a glass top and no bottom– flexible as it can be made as long and as wide as the gardener wishes.

The cold frame was the foundation for the early development of intensive commercial hort.

Most of the crops grown in the cold frame are planted in late summer/early fall. That’s because the rate of plant growth diminishes with shortening days in fall

It can be described as storing them in a large translucent refrigerator crisper drawer.

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Cold frames and hotbeds are an inexpensive structure for growing cool-weather crops

in early spring and fall. Recycled shower doors or windows work well. They range

from simple to elaborate. Cold frames rely on the sun for their sole sources f heat.

Heat is collected when the suns rays penetrate clear plastic or glass even fiberglass.

Building a cold frame takes a few hours and requires only simple tools such as a

hammer, drill, nails or wood screws, and a saw.

Decide on the dimensions for your cold frame. Popular dimensions are 3 feet by 6 feet

or 4 feet by 8 feet. The height should be at least 8 inches, with 12 inches being better.

Keep in mind that if you are small framed yourself, it may be difficult to reach the

middle of a 4 foot-by-8 foot bed when seeding or weeding

Measure and cut two sides and two ends for each cold frame from untreated lumber.

Fasten the ends to the sides using galvanized L-brackets and galvanized

screws.Reinforce 8-foot sides at the 4-foot point by pounding a wooden or metal

stake into the ground immediately abutting the side boards to increase rigidity.

Reinforce 6-foot sides at the 3-foot point.Add shims to the top of both ends that

angle from a maximum height of 1 inch at one end gradually tapering to a minimum

height of a 1/2 inch at the opposite end. This will allow precipitation to shed off the

lid during bad weather.Make two lids per cold frame with a width to match the cold

frame and a length half that of the cold frame from untreated 1 inch-by-3 inch

untreated boards. Eliot Coleman has plans in his book that call for super-expensive

rigid plastic. For a less expensive--albeit less durable--alternative, use heavy-duty

plastic film sold in fabric stores as tablecloth covering material. Cut the plastic 3

inches larger on each side than the lid frame, and staple it to the frame with heavy

duty galvanized staples. The plastic should be taught when you are done stapling.

When done, the lids simply rest atop the cold frame itself so you can easily remove

them when you need to seed, weed or water your garden.

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It is necessary to vent the frames to prevent overheating in fall and spring but ingenious, temperature-activated ventilating arms can be installed to look after tat for you.

Single layer of glass creates a microclimate in which the nighttime temperatures inside the frame can be as much as 20 degrees F warmer.

Much of the havoc that freezing can wreak on winter vegetables is a function of how wet the plants are. The glass roof of the cold frame protects the crop inside from pounding winter rains.

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Keep a a thermometer in the cold frame to give you some idea of the temperature inside. Temperature control involves venting excess heat. I am all in favor of the mechanical helpers which use a heat activated pressure cylinder that expands with enough force to lift up to 20 pounds. You might find old windows weigh more than this But speaking for someone who works, these are essential.

With cold frames it is always better to error on the cool side and vent the frames excessively rather than run them too warm.

You will vent in spring and fall but by the time winter arrives the system is basically dormant.

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Hotbeds are heated by soil- heating cables, steam carrying pipes or fresh, straw manure buried beneath the plant rooting zone.

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The tunnels are not heated, but having an emergency heat source handy is cheap insurance for protection from extreme cold snaps, heavy ice or snow.

Whether you’re a backyard gardener, a market gardener or a commercial grower, you can build a high tunnel to meet your needs in just a couple of days using simple hand and power tools.

Benefits of building a high tunnel

The “high” part of the name means that the tunnel is high enough that you can stand up straight inside. “High tunnel” is a somewhat loose term. It includes everything from tall, Gothic arch structures to Quonset-style “hoop” houses, which also are known as cold frames. In tunnels with high sidewalls, there is plenty of room to operate garden tillers and even small tractors with tillers, mulch layers and bed shapers.

In extreme heat, the plastic skin can be easily shrouded in, or even replaced with, shade cloth. Add drip irrigation, minisprinklers and maybe a fan or two, and crops inside the tunnel will be almost as cool as veggies in the supermarket produce case.

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A high tunnel is similar to a green- house structure that may be the most versatile of all the season extenders. High tunnels offer the opportunity for the grower to get a crop in early in the season, to stay in production later in the season, and, possibly to produce a crop such as greens through the winter.

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The standard tunnel is 14 feet wide, 96 feet long, and 7 feet 6 inches tall at the center. Tunnels are 20 feet wide or less, for good cross ventilation and reduction of snow accumulation on the roof in the winter. The Quonset frame consists of metal bows made by bending steel pipe or tubing. Potential stresses caused by the weight of snow or heavy wind must be considered. Metal pipes, which are drive- en into the ground approximately 2 feet deep and every 4 feet of the high tunnel length, provide support for the Quonset frame. The bows fit into the ground pipes and are attached by bolts. The ends of the structure can be plastic or wood on a wood stud frame, but should be removable to allow access for tillage equipment and to increase ventilation in the summer. The structure is type- call covered with a single layer of 6 mil polyethylene with provisions for rolling up the sidewalls. The poly is secured onto a batten board on each side of the high tunnel about 3.5 feet above the soil line. A vertical sidewall helps to keep rain out of the tunnel and when rolled up, provides ventilation. A pipe is then attached to the loose bottom end of the plastic along the length of the structure. A “T” handle on the end of the pipe is used to roll the plastic onto the pipe to open the sides. Cross ventilation is assisted by wind and has proved to be very efficient. The key to successful use of the high tunnel is to spend the time laying out and preparing the site for construction. The better the tunnel is constructed, the easier the roll-up sides will work and the easier it will be to ventilate.

Crops are grown directly in the soil inside the high tunnel and productivity can be maintained into or beyond the conventional growing season as long as the side vents are carefully managed.

During periods of cold weather the sides are lowered in the afternoon to hold heat and then raised in the morning to vent before temperatures inside get too high. The floor of the structure is covered with a layer of 6 mil black plastic. This helps to raise the temperature inside the house, to control weeds, and to prevent evaporation of

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Again the nice thing about the High Tunnel is, the tunnel is large enough for the grower to plant, monitor, or harvest the crop from inside the structure.

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Greenhouses, although generally more expensive than other season extension techniques, provide the greater degree of control. Because they are permanent, greenhouses can more easily be insulated and heated. Automatic ventilation systems can also provide increased reliability with relatively less labor. Because you are actually creates an artificial condition you can have a problem with pests building up.

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Pollination is only a factor in flowering plant production such as tomatoes, peppers, cucumbers, and melons.

Generally, only greenhouse-specific varieties are utilized in high tunnel production. In most cases the air moving through a high tunnel will provide adequate pollination for tomatoes and peppers; however, bees are required for pollination of cucumbers and melons. To improve pollination of tomatoes and peppers, bumblebees or air blowers can be used, depending on the crop. While bumblebee colonies are fairly expensive, they can provide excellent pollination under favorable conditions. A pesticide program must accommodate the needs of the bees. Gynoecious cucumber cultivars do not require pollination. Generally, bumblebees pollinate strawberries and tomatoes grown in heated greenhouses. Wind pollination is sufficient in high tunnels with roll-up sides; however, it can be improved by using bees. Greens and herbs require no pollination, making them much easier crops to manage in a completely indoor environment, especially in the off season.

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