Garden Know-How: Extend Your Growing Season

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July 21, 2017 | 28,343 views

Story at-a-glance

  • With a little know-how, innovative, do-it-yourself “season stretchers” in your garden can help extend your veggie-growing potential well beyond the norm for your plant hardiness zone and facilitate a much earlier harvest
  • Whether they’re small enough for just one plant or for a whole row, mini greenhouses and cloche ideas can protect young plants while forcing faster growth
  • A cloche, cold frame or garden tunnel can increase productivity by as much as six weeks, both early in the season when a late frost might surprise you and in the fall to give already-producing plants a chance to produce more
  • Other ideas include painting water bottles flat black and placing them next to plants in the garden so they can absorb the warmth of daytime sun, then release their warmth at night

By Dr. Mercola

No matter where you live, if you enjoy gardening and grow your own vegetables, herbs and other plants, you probably wish the season were longer. Who doesn't love picking luscious red tomatoes right off the vine, or finding an abundance of crisp, green cucumbers hiding under their fanlike foliage?

Gardeners who live in the chilliest plant zones, though, have a definite disadvantage, as they may be forced to wait until May to sow their first seeds into the soil, and later watch their vibrant garden production come to a chilly halt as early as the first frost. Sad days, indeed. But as the headline notes, there are ways to extend your growing season and increase your yield.

It may look a little different from your traditional gardening routine, but in no time at all, you can begin implementing a few simple DIY projects to keep you in peppers, cantaloupe and beets longer than the seed packets say is typically possible. In fact, you may be able to start your gardening season as much as six weeks earlier and extend it nearly as long on the other end. Besides being a cheaper and altogether healthier proposition than buying grow lights for your basement, all you need is a little bit of ingenuity for a lot more food.

Mini Greenhouse Effects

In early spring, when frost is still clinging to the grass, trees and rooftops, most gardeners are busy perusing seed catalogues for new varieties, but you can be planting them. Some vegetables, like peas, onions, lettuce and other leafy greens, enjoy a little nip in the air, but others, including tomatoes and bell peppers, do much better when the soil they're planted in is warmer. That's where these simple, dome-shaped structures come in handy.

Cloches, cold frames, plastic-covered tunnels and other garden "hacks" can help facilitate a much earlier harvest. Depending on your needs, they're lightweight and relatively inexpensive to build, but strong enough to withstand cold nights, wind and freezing rain. As Mother Earth News explains, they give plants a "leg up" via free solar energy:

"Simple plastic cloches or plastic-covered cold frames raise nighttime temperatures 4 to 5 degrees, but you can double that number by throwing on an insulating blanket in the evening. Or triple the protection by adding black water bottles, which release stored daytime warmth after the sun goes down."1

Questions about such projects usually deal with what materials are needed, whether they're difficult to build and how expensive they're likely to be. Luckily, you might not even have to hit the store at all, but instead use what you already have on hand.

A 'Cloche' Is Like a Hat for Your Plants, Protecting Them From the Elements

In the 1920s, women often wore close-fitting hats called a cloche, which in French means "bell." A bell-shaped dome over garden plants, also called a cloche, can trap the warmth of the garden soil and air during the day and keep plants warm during chilly nights. They can protect an individual plant, a row of plants or a whole section, depending on such factors as prior planning, garden size, plant placement and available materials.

Something as simple as a translucent milk jug or clear plastic juice bottle with the spout cut off qualifies as a cloche to cover single plants. Save them or ask friends and family members to save them for you, too, rather than just throwing them away. Recycling centers may also have some available. They're easy to stack in your garden shed to use from year to year. Mother Earth News suggests another idea:

"Before cutting off the bottom of any jug, I make a V-shaped slit in the top of the handle. Later, I can shove a long, slender stick through the slit and down into the soil to help hold the cloche steady in the wind."

Plastic cake covers, cardboard boxes, old margarine containers, old Styrofoam coolers, baskets, upturned flower pots — anything that fits over the top of plants without bending or crunching them can work as a cloche.

Tunnel Vision: A Cloche Alternative

If you have a whole row of plants you want to protect, contriving a tunnel is quick and easy with just a few inexpensive items. They're convenient in the early part of the season when plants are small and less apt to blow over in a strong wind.

For the "ribs" or frame of the tunnel, fencing wire or concrete reinforcing wire work well, but you can even use slender green branches or saplings from wooded areas because they're flexible and won't snap in half. Narrow, flexible pipe also works; one idea is to place symmetrical brackets on the sides of a raised bed garden. Simply place the pipe into the bracket on one side, bend it over the top of your plants and insert it into the other side.

For the protective cover, recycling an old shower curtain works fine for smaller areas, but for a tunnel, clear plastic sheeting comes on a roll so it can be cut to size. The tunnels need to be sturdy in case of heavy snowfall, so you'll need to allow for a 2-foot overhang on each side. To hold down the edges of the plastic, use squared-off railroad ties, bricks or concrete blocks.

Like a tent, you can open both ends of the tunnel to allow air to flow through. Simply fold or bunch up the plastic over the "ribs" on each end using clamps, clothespins or spring clips.

You can also cut V-shaped vents into the sides and/or tunnel ends and use squares of masking tape to open or close them. The vents can be left open or closed depending on the temperature. In case a real cold snap occurs, you can throw a few old blankets over the top of the tunnel for extra insulation. These can be left on for up to four days in case the cold lingers.

Mini Greenhouses Are Easier to Make Than You Might Think

For rows of tall, full-sized plants such as tomatoes, you need a taller profile and a lot more plastic so the unit will be secure in strong wind — or protect them from critters like deer that may steal into your garden at night and decimate your crops. One way to make a mini greenhouse is to start with welded wire or mesh fencing with 2- to 4-inch-spaced square openings. Five-foot-long strips can be bent to make coverings that stand a foot high for beds measuring 30 to 36 inches wide. Here are easy directions to follow:

Directions

  1. Bend the wire into the shape you want
  2. Lay it top down on a sheet of clear plastic
  3. Fold the plastic up and over the long edges of the wire
  4. Fasten the folded plastic inside the tunnel with clear packing tape
  5. Fashion a half-moon-shaped drape of plastic sheeting and attach it on both ends so you can close the tunnel in cold weather.

The beauty of these tunnels is that they can be made to easily lift off the beds so you can water and weed and allow your plants to get daytime sun, then pop the tunnels back over the plants when they need protection again. They can be secured to the ground with "staples" made from wire coat hangers in case it gets windy or to protect from animals. A similar screen using mesh instead of plastic can keep birds from eating the berries off your raspberry bushes.

Cold Frames: A Halfway House for Plants

A cold frame is a boxed-in growing area with a clear glass, plastic or acrylic glass covering designed to trap solar heat inside. They're a perfect way to "harden off" tender seedlings, the term used to describe the gradual process of introducing young plants to the elements outside to make them stronger and more resilient. Gardening Know How explains:

"When plants are grown from seed indoors, they frequently are grown in a controlled environment. The temperature is pretty much maintained, the light is not as strong as full sunlight outside and there will not be much environmental disturbance like wind and rain.

Because a plant that has been grown indoors has never been exposed to the harsher outdoor environment, they do not have any defenses built up to help them deal with them. It is much like a person who has spent all winter indoors. This person will burn very easy in summer sunlight if he/she has not built up a resistance to the sun."2

Cold frames are generally stationary, but you can also put them together so they're movable. In fact, some gardeners take their smaller, portable cold frames outside for a few hours and back inside again over several days.

Permanent cold frames are best situated on a south-facing slope, but flat ground works fine, too; just make sure they're placed in the sun. Materials can consist of anything that accomplishes the purpose at hand. If they're covered with a material that will allow light and heat inside, just about anything can work. Innovative ideas might be:

A simple wooden latch or screen door-type hook and eye is all that's necessary to keep the lid on your cold frame closed tightly, or get creative and use something like an old bicycle tire with plastic screwed on top. One thing that makes such projects so much fun is being able to think outside "the box."

More 'Outside the Box' Garden Warmers

Innumerable ideas have been spawned by creative innovation. As Plato aptly quipped, "necessity is the mother of invention." If you're determined not to spend money, rattling around in your garage, basement or shed to see what you have may spark inspiration. With that in mind, the humble 2-liter plastic bottle (or any size, really) has more uses than you can shake a stick at. They can be glued top-to-bottom and side-by-side, to make a "wall" inside a simple wooden frame. Mother Earth News suggests this idea:

"Even when anchored by mulch, strong winds may blow away many cloches — except for heavy ones such as the Wall O' Waters, which weigh about 25 pounds when filled. A circle of water-filled plastic drink bottles duct-taped together is heavy enough to stay put and hold down the edges of a sheet of plastic tucked around the cloche for extra frost protection."3

Try painting plastic water bottles flat black to absorb the warmth of daytime sun, and they'll release that warmth at night. Create a protective circle around individual plants, or line them up, sides touching, between rows. You can even duct-tape them together for easier transport. A large, plastic water-cooler-sized barrel — or several — can do the same thing for larger plants.

They warm up from the sun during the day and release their heat at night so you don't even have to move them. To lengthen your garden's growing season, beyond creativity, the only other thing to do is keep an eye on the weather.

[+]Sources and References [-]Sources and References

  • 1, 3 Mother Earth News February/March 2007
  • 2 Gardening Know How January 24, 2017