Should You Cover Your Garden with Plastic for Winter? The Pros and Cons

Clearing land for new garden space can be truly back-breaking work. Use these tips for how to use the power of sunlight and black plastic to kill weeds instead. The method uses no chemical sprays, is easy to do, and keeps the soil structure intact. Once the plastic has had time to work and peeled back, you’re left with a clean slate of cleared land that you can begin growing on immediately. It’s an eco-friendly way to clear land without having to use herbicides.

Once you decide that you’re going to start a new garden or garden bed, the questions begin. The big one is usually around figuring out the best way to convert a lawn into a productive garden. It’s clear that you can’t plant directly into it since grass will outcompete crops. The soil probably also needs amending with organic matter, and to do that, all the vegetation must be removed. One way or another, you’re going to need to clear the land of everything currently growing on it. Instead of hacking away at turf or double-digging, the way that I recommend doing it is to use black plastic to kill weeds. It’s far easier and more effective than the alternative.

This is exactly how I created parts of my last two vegetable gardens and two large flower borders. Doing it this way saved me an incredible amount of time and energy! Using black plastic is the main way I recommend clearing land without using herbicides since it’s easy and suitable for organic gardening. The before and after photos below show how I covered an entire area and then gradually peeled the plastic back. Bit by bit, I transformed a weedy plot of land into a beautiful and productive veggie patch.

As the cold weather approaches, many gardeners consider covering their vegetable beds and flower gardens with plastic sheeting to protect plants from frost and cold temperatures. But is this really the best winterization method? Here we’ll examine the pros and cons of using plastic covers on garden beds over winter to help you decide if it’s right for your landscape.

An Overview of Covering Gardens with Plastic in Winter

Covering garden beds with plastic sheets or tarps for the winter is a practice that many gardeners swear by The idea is that the plastic acts as an insulating layer to protect plants from frigid air temperatures and retain heat absorbed by the soil during the day, This can help buffer delicate plants against frost and freezing, The plastic also blocks light which prevents weeds from sprouting And it can conserve soil moisture,

During winter dormancy, some gardeners cover their perennial flower beds, roses, strawberries and other ornamentals susceptible to winter die-off with plastic. Vegetable gardeners may cover empty beds where early spring crops like peas will soon be planted. The warmed soil gives seedlings an earlier head start once the plastic is removed in early spring.

So in theory, plastic covering allows you to grow plants that might not otherwise survive your winter, and get a jump on spring planting. But it also has some potential drawbacks. Let’s analyze the pros and cons so you can decide if it’s right for your landscape.

Potential Benefits of Covering Gardens with Plastic

Here are some of the main advantages that motivate gardeners to cover beds with plastic for winter

Warms the soil – The black plastic absorbs heat from sunlight during the day and releases it slowly at night. This can warm the soil underneath by several degrees compared to unprotected ground.
Earlier spring growth – The warmer soil temperatures under the plastic in early spring hasten plant growth. This allows earlier planting and harvests.
Controls weeds – The solid plastic sheet blocks sunlight entirely preventing weed seeds under it from sprouting. This can significantly reduce weeding labor when you uncover beds.
Conserves moisture – The plastic minimizes surface evaporation which keeps soil underneath moist. This helps plants remain hydrated in winter and saves watering labor later.
Protects from frost – The insulating properties of the plastic may protect covered plants from a degree or two of frost. Not reliable for hard freezes, but potentially helpful in shoulder seasons.
Takes up leftover plastic – Making use of old plastic tarps or drop cloths that might otherwise end up in a landfill gives them a second life.

Potential Problems With Covering Gardens in Plastic

However, there are also some drawbacks to covering garden beds with plastic over winter that you should consider:

Promotes disease and fungi – Wet soil trapped under solid plastic can foster mildew, mold, blights, and root rot issues. These may linger into spring and infect young seedlings.
Harms helpful soil organisms – The anaerobic environment under plastic kills off beneficial earthworms, bacteria, and other critters that maintain healthy soil ecology.
Kills living mulches – Any cover crops like clover or rye you have growing will suffocate and die when covered for an extended period.
Traps pests – Snails, slugs, and other pests may take shelter under the plastic and breed rapidly in the warm, moist conditions it creates.
Looks messy – A big blue plastic tarp covering a garden bed is an eyesore to many gardeners, and neighbors may complain.
Blows away in wind – The plastic sheeting catches gusts of wind like a sail and can fly off the bed if not weighed down properly on all sides.
Creates plastic trash – Even thicker plastic sheets degrade over a season. This leaves you with smaller fragments to responsibly dispose of later.

Best Practices for Covering Beds

If you decide the benefits outweigh the risks in your climate, here are some tips for safely using plastic:

Use only UV-stabilized, heavy duty 6-10 mil construction grade plastic. Lightweight thin plastic will quickly shred and fly away.
Secure all 4 edges with heavy bricks, rocks, or garden staples. Bury edges if possible. Check often for wind lifting edges.
Apply plastic as late in fall as possible once cooler weather settles in so you don’t trap active pests underneath while still warm.
Remove the plastic as soon as your soil thaws in early spring. Especially uncover immediately once plants start growing underneath.
Reuse intact plastic sheets over subsequent winters. Properly dispose of any fragments that have become brittle or ripped.
Replenish soil nutrients by top dressing beds with finished compost after removing plastic.
Scout for pests and treat any fungal outbreaks quickly before they spread to young plants.

Alternatives to Plastic Coverings for Winter Protection

If you want to avoid the risks of solid plastic coverings, effective organic alternatives exist:

Apply 6-8 inches of shredded leaves, straw, or evergreen boughs as loose mulch cover. Still provides insulation against frost while allowing airflow.
Grow cold-hardy cover crops like winter rye and hairy vetch. They continue generating organic matter through winter while suppressing weeds.
Cover beds with breathable row cover fabric hooped over wires. Allows ventilation while still trapping warmth. Can incorporate low tunnels.
Heavily amend soil with finished compost in fall to feed soil biology and boost organic matter before winter.
Use corn gluten-based organic pre-emergent herbicides in spring rather than relying on plastic sheeting for weed prevention.
Employ organic physical controls like copper tape, diatomaceous earth, and insect barrier fabrics to prevent pest damage without plastic.

Covering vegetable gardens and ornamental beds with plastic sheeting or tarps for winter does offer some benefits, especially in regions with harsh winters. But it also carries risks like encouraging soil diseases, pests, and killing off helpful soil life. Safer organic alternatives like mulching and cold-tolerant cover crops typically provide adequate insulation and protection for most gardens. Carefully weigh your specific climate and gardening goals when deciding if plastic covering is the right solution for winterizing your beds. With prudent preparations, most gardens can successfully weather winter without plastic.