Should My Raised Garden Bed Be Covered With Plastic?

Raised garden beds are a popular choice due to their ability to create a barrier between the soil and the ground, preventing weeds from poking through, keeping out toxins, and ensuring pests don’t enter. The ideal bottom layer should help with drainage, suppress weeds, improve soil, prevent rodents and pests from burrowing in, and protect the soil from potential contaminants. Different materials, such as cardboard, newspaper, straw, wood, and rocks, can be used for lining raised beds.

However, it is essential to avoid using plastic underneath the bedding soil, as it can prevent drainage and drown plants’ roots. If you have a weed and pest problem, consider installing a combination of metal mesh, fabric, hardware cloth, and cardboard. If your budget doesn’t allow for weed barrier cloth, add several layers of cardboard to the bottom of your raised bed before filling it.

One downside to using plastic at the bottom of your flower bed is that it may not allow water to properly drain. However, raised garden bed linings made from plastic are effective in keeping out stubborn weeds by absorbing water into the wood and drying out the bed quicker. Black plastic will not raise soil temperature like transparent plastic or kill pathogens or fungi, but it can kill weeds more effectively.

To ensure the best results, make sure that the plastic is much higher than the soil you plan to use in the garden bed. It is also important to ensure that the plastic is not too thick or too thin, as this can affect the effectiveness of the weed barrier.

What is best to put on bottom of raised garden bed?

Cardboard or newspaper can be used to line the bottom of raised garden beds to deter pests and weeds on a budget. Choose cardboard with minimal markings and no tape for a safer option. Stainless steel gopher nets can be used for extra protection, as seen in Vego Garden’s modular cover system. Landscaping fabric can prevent soil erosion, promote water retention, and keep out invasive grasses. While it doesn’t break down over time like cardboard, it limits shallow-rooted plant growth, earthworm movement, and soil mixing. Deeper beds may not need it unless a weed problem is present.

What do you put in the bottom of a planter for drainage?

To line the bottom of a planter for drainage, use broken pieces of pot, old newspaper, or a plastic liner. This prevents compost loss and blockage in the drainage holes. For small planters, old newspaper allows excess water to drain freely while preventing compost flushing out. For outdoor planters, use a plastic liner or pond liners, which can be cut into the base and filled with compost. Trim any excess liner from the top.

To improve potting soil, add soil amendments like perlite, mulch, and sand to prevent the compacting of compost and fertiliser inside the planters. This will prevent the soil from becoming too compacted and promote better drainage. Using handheld gardening tools can also be helpful in filling the planter with compost.

Do raised beds need a membrane?

A geotextile membrane liner is recommended for better drainage in a raised garden bed, while damp proof membranes are recommended for the sides and buttresses. Soil should be chosen based on the type of plants to be grown. Raised beds are ideal for gardens with poor soil, as they allow for selection of the type. Rich compost mixtures are expensive but effective, but topsoil mix and soil improver or compost mix can be used. Sandy soil is the best all-rounder.

Using bought-in topsoil allows for more control over weeds. Homemade compost or manure can be made richer, but check if it’s suitable for your needs. Plants and vegetables can be supported with solid and liquid fertilizers. Raised beds can grow almost anything, especially edibles, as the extra height makes the regular cycle of sowing, maintaining, weeding, and harvesting easier. Deeper-rooted varieties may need to be planted in taller beds depending on the surface of the raised bed.

Should I put plastic in the bottom of my raised garden bed?

Plastic sheets or tarps are commonly used as liners in raised garden beds to provide protection and insulation. However, they may not allow proper water drainage, leading to issues like root rot. Instead, use plastic as a liner on the inner sides of the bed, but use a more permeable material for the bottom, such as landscape fabric or wire mesh.

For herb or vegetable gardens, it is important to know the specific type of plastic used and ensure it is made of food-grade materials to avoid toxins leaching into the soil or greenery. To line a garden bed, choose the perfect spot and line the bottom with your chosen material. If using mesh wire or landscape fabric, secure it with landscape or garden staples and ensure it fits against the bed’s walls. If using landscape fabric, create a tight barrier against weeds by folding the excess material upward on the inside walls.

A liner is essential for insulate the soil from extreme temperature changes and protect against other threats, such as digging pests. To prepare a raised garden bed for growing, refer to the blog post “How to Prepare a Garden Bed for Healthy Plants” for helpful tips and information.

Why do you put cardboard under a raised bed?

The use of cardboard as a growing medium has been demonstrated to create a damp environment that attracts earthworms and other beneficial soil microorganisms. It can be utilized in raised beds and vermicomposting bins, functioning as bedding and an occasional food source.

Should I line my planter box with plastic?

Plastic liners are a popular choice for gardeners due to their ability to retain moisture, especially in terracotta or metal planters. They are inexpensive and easily accessible, making them a popular choice for both casual and serious gardeners. However, plastic liners restrict air flow, which can be harmful to plant health. They are best suited for plants that don’t require high air circulation and are cost-effective for reducing water evaporation and extending the watering interval.

Should I put anything in the bottom of my planter box?

To line the bottom of a planter for drainage, use broken pieces of pot, old newspaper, or a plastic liner. This prevents compost loss and blockage in the drainage holes. For small planters, old newspaper allows excess water to drain freely while preventing compost flushing out. For outdoor planters, use a plastic liner or pond liners, which can be cut into the base and filled with compost. Trim any excess liner from the top.

To improve potting soil, add soil amendments like perlite, mulch, and sand to prevent the compacting of compost and fertiliser inside the planters. This will prevent the soil from becoming too compacted and promote better drainage. Using handheld gardening tools can also be helpful in filling the planter with compost.

Should I put a tarp under my raised garden bed?

Tarps can protect soil from eroding over winter, but organic mulch may be a better choice. Woodchips, provided by some municipalities, can be placed on vegetable beds and removed in the spring, but are not suitable for perennial beds. Plastic tarps can damage beneficial organisms in the soil and may not reduce weed seed occurrence during winter. Clear tarps can be used to “solarize” the soil during hot weather, but seeds may lay dormant and sprout once temperatures warm.

Some farms use tarping to reduce seeds over winter, but this requires specific timing and is usually done on larger beds, which may provide more heat retention benefits. The process can be more complex than just covering beds in tarps. The size of beds, types of weeds, and winter temperatures may influence the outcome, and research on this topic is ongoing, with much of it based on farms rather than small raised beds.

What to put in the bottom of a planter without drainage holes?

To plant in a container without drainage holes, follow these steps:

1. Layer the bottom of the container with landscaping rocks, about 2-3 inches deep.
2. Add Horicultural Charcoal, fill with potting soil, and transfer your plant.
3. Drill a hole in the container if desired, but it’s sometimes an option. If you don’t want to drill a hole, you can still plant in any container provided you create a more ideal environment.
4. Use pea gravel, river jacks, or decorative stones in any variety or color for the container. If your container is tall and needs more than 2-3 inches of rocks, cut landscape fabric to the size of the container and line the bottom with layers underneath the rocks. This works best with containers that are not visible, as it is not particularly attractive.

Do you cover the bottom of a raised garden bed?

To keep out weeds in raised beds, add physical barriers like burlap or weed barrier cloth to the bottom of the bed before putting in soil. You can also use several layers of cardboard as a weed barrier, but remove tape and glossy print areas first. The cardboard will break down in about 4 to 6 months. If you live in a location with pests like voles and moles, put hardware cloth at the bottom of the bed before filling it with soil. Layer landscape fabric or cardboard on top of the hardware cloth for weed control.

These barriers provide protection without sacrificing good drainage. Most raised beds with bottoms are made of steel, as it is strong enough to support the weight of the entire bed once filled with soil.

Should I put a barrier under my raised garden bed?

Raised garden beds should be lined with materials that create a barrier between the soil and the ground, preventing weeds from entering, toxins from being released, and pests from consuming the garden. Options include wide-mesh hardware cloth, stainless steel mesh, landscape fabric, burlap sack, or newspaper/cardboard. Wide-mesh hardware cloth is effective in keeping weeds and burrowing animals out, while burlap sack allows earthworms to pass through, aerating and enriching the soil for plants. Staple the cloth to the bed frame during construction and it should serve its purpose for years to come.