Will Bulbs Grow Through Landscape Fabric? The Truth About Using Weed Barriers in Gardens
Landscape fabric, which is also called weed barrier fabric, is often used to keep weeds out of garden beds. But what happens to bulbs that are planted in the same areas? Can daffodils, tulips, and other bulbs grow through the fabric?
The Purpose of Landscape Fabric
Landscape fabric, which is made of woven or nonwoven polypropylene, is put on top of the soil before mulching. It serves several useful purposes:
- Blocks most weeds from germinating and emerging
- Prevents existing weeds from poking through the mulch layer
- Conserves moisture by preventing evaporation
- Controls erosion by keeping soil in place
The key benefits come from landscape fabric’s ability to block sunlight and smother weeds before they can establish. At the same time, water and air can penetrate the fabric to reach the soil and plant roots below.
The Downsides of Landscape Fabric
While landscape fabric seems like a garden miracle product, it does have some downsides:
- Deteriorates over time and may need replacing
- Can prevent moisture from soaking into clay soils
- Makes it difficult to plant new plants without cutting holes in the fabric
- May cause soil compression and poor aeration
- Can harbor voles and pine mice who chew through and nest under it
Before putting fabric over whole garden beds, you should give it a lot of thought. It might only work well on paths and in places where plants are already established.
The Effect on Flower Bulbs
The important thing to remember is that landscape fabric placed on top of bulbs will stop them from growing properly. Flower bulbs have roots and shoots that need to come up through the ground every year.
Fabric and other solid barriers over the top of bulbs can cause them to rot and decline over time. Their natural growth process becomes stunted.
Some light penetrating fabrics may allow very limited shoot growth, but this is not ideal and will severely limit the plants. Overall landscape fabric is incompatible with the seasonal growth habits of bulbs.
How to Plant Bulbs Through Landscape Fabric
While landscape fabric prevents natural bulb growth, it is still possible to plant bulbs in areas with the fabric in place. Here are a few options:
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Cut an X-shaped slit in the fabric and plant the bulb through the hole beneath. Make the hole large enough for foliage and flowers to emerge.
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Layer newspaper or cardboard over the fabric before planting bulbs. The paper will decay allowing shoots to emerge.
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Use a gravel mulch rather than bark or leaves. Shoots can push through gravel more easily.
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Choose bulbs with very sharp foliage tips that can penetrate fabric, like tulips or daffodils. Avoid rounded shoots like hyacinths.
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Consider removing sections of fabric altogether and replacing with mulch once bulbs are planted.
Even using these approaches, growth may be limited and flowering reduced. Best practice is to avoid using landscape fabric where you intend to regularly plant bulbs each year.
Natural Weed Control Options
While landscape fabric is unnecessary when planting bulbs, controlling weeds is still important. Here are some non-fabric solutions:
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Mulch heavily around bulbs to block light from reaching weed seeds. Replenish mulch as needed.
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Maintain a layer of dense, competitive groundcover plants like sedums between bulbs. This helps suppress weeds.
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Carefully hand pull or hoe any weeds that do emerge. Be gentle around emerging bulb foliage.
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Use corn gluten meal, a natural pre-emergent herbicide, to prevent annual weeds. Apply in spring and fall.
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Try DIY vinegar-based herbicidal sprays on young weed seedlings. Reapply frequently.
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Sprinkle salt directly on problem perennial weeds such as dandelions to dehydrate and kill the roots.
The Takeaway
For the best results planting flower bulbs, avoid using landscape fabric atop the planting areas. While it is possible to plant bulbs through holes cut in the fabric, growth will likely be diminished. Rely instead on heavy mulching and vigilant weeding to control weeds while allowing bulbs to emerge naturally each spring. With a little diligence, your garden can flourish fabric-free!
Aesthetically speaking, when the weed fabric is exposed, it looks just awful – horrendous, ghastly, dreadful.
Did I mention how bad it looks when the mulch slides off?
Many of the old weed fabrics aren’t water and gas-permeable.
I’ve often seen soil under and on top of old weed fabrics that was as dry as a bone, packed down as hard as cement, and the color of baked clay. Even with layers of compost and mulch on top, the plants were dying slowly because they were lacking nutrients and water. Since there isn’t much water or gas exchange at the surface or in the soil, there isn’t much activity in the soil food web. This is immediately apparent by the distinct lack of earthworms and insects just below the surface. Conversely, when used in very wet or soggy areas, the weed barrier can trap water beneath it, creating a swampy mess.
BIGGEST Weed Fabric MISTAKES We’ve Made!
FAQ
Will plants spread through landscape fabric?
Perennial flowers can grow through landscape fabric if the fabric is permeable. That means that the fabric allows water, air, and nutrients to pass through and reach the roots of the plant. This is why the flowers won’t be able to grow through fabric that doesn’t let these things pass through.
Will bulbs grow through ground cover?
Bulb shoots are adept at finding their way up through low groundcover plantings, such as commonly used vinca (Vinca minor), sweet woodruff (Galium odoratum), deadnettle (Lamium), leadwort (Ceratostigma), and creeping sedum.
Can plant roots penetrate landscape fabric?
Once weeds start growing over top of landscape fabric, they can be quite hard to pull out. Often the root hairs penetrate the fabric and get deeply embedded.
When not to use landscape fabric?
Landscape fabric is not ideal for all gardening scenarios. It’s generally not recommended for areas with frequent planting or transplanting, where it can hinder water and air circulation, or where long-term soil health is a priority.
Can you plant flower bulbs through landscape fabric?
Planting flower bulbs through landscape fabric can be a pain. You can plant the bulb in the ground by cutting a hole in the fabric, but animals like gophers can sometimes damage the bulbs.
Can landscape fabric affect plant growth?
Yes, they can. But, landscape fabric may constrict the growth of plants. Not all, but many perennial plants will be inhibited from growing larger over time, because they have no room to expand. While we’re on the subject of soil and plant health, let’s sidestep here and talk a little about river rocks.
Can landscape fabric be used to transplant plants?
Landscape cloth is not conducive to planting new plants, transplanting or dividing existing plants. An area that has landscape fabric is a nightmare to plant in. You have to cut through the fabric in order to place new plants. Have you ever tried to transplant a perennial that is growing in a bed where landscape fabric was used?.
Can perennials grow through landscape fabric?
Yes, they can. But, landscape fabric may constrict the growth of plants. Many perennial plants won’t be able to get bigger over time because they don’t have enough room to grow.
Does landscape fabric stop weeds?
The roots of the weeds grow through the landscape fabric making it difficult to pull them. Think about how many times you see weeds growing on gravel or in concrete cracks. If weeds grow in those places, landscape fabric will not stop them. Landscape cloth is not conducive to planting new plants, transplanting or dividing existing plants.
Do weeds grow in landscape fabric?
Eventually organic matter will accumulate on top of the fabric (even if the fabric is covered with river rock or wood chips) and it creates the perfect atmosphere for weed seeds to germinate. Also, weeds (especially dandelions) will eventually grow through the landscape fabric (see example below), both from the bottom and top.