Overnight, your vegetable garden received a long, hard rain and half of it is waterlogged this morning. Is there anything you can do to improve soil drainage in your vegetable garden?
There are a few things you can do now to improve drainage, but if your veggies are already growing, the best fix is to start over next year. If you’re in the beginning stages of planning a vegetable garden, take a hard look at how water moves through your property. Avoid creating the garden in low areas. Look for higher ground instead.
Quick fixes for vegetable garden drainage
If the vegetable garden is already planted, it’s unlikely you’ll want to dig up the plants, build up the soil with organic matter to improve drainage, and then replant. A quick fix or two for poorly drained soil should get you through the growing season while you decide on a permanent fix for the drainage in your vegetable garden next year.
1. Install a temporary dam
Is runoff flowing into your garden after the storm? Use bags of mulch, sand, pieces of metal or plastic, or other objects to create a dam or to divert water away from or around the vegetable garden bed.
2. Dig a trench
A trench dug around the vegetable garden creates a way for water to bypass the bed. Although this is a temporary fix, the trench should be deep and wide enough to accommodate the rainfall.
Fill the trench halfway with gravel. Depending on your landscape, you may have to create a temporary catch basin where water from the trench can go.
Long-term solutions for vegetable garden drainage
A permanent fix may be needed to keep the vegetable garden from being washed away by heavy rains and poor drainage. Raised beds are probably the most efficient way to get your vegetable garden back on track with improved drainage in the least time.
3. Unenclosed raised vegetable garden
Once the plants are gone, you can develop the bed where it is by building it up. Raising the height of the vegetable garden should prevent it from being flooded.
Raise the vegetable garden with compost, well-rotted manure, chopped leaves, or other organic material. Soil conditioners, such as vermiculite and perlite, also help.
Brownie Points: Organic matter helps poor drainage in clay soil and fast drainage in sandy soil. Organic matter and soil conditioners create more space among dirt particles to aid drainage while helping the soil retain moisture.
By adding height with organic matter, you’re essentially building a raised bed. A raised bed does not have to be enclosed. It can be free-standing, about 12-inches high and 3 feet wide, with outward sloped sides. The bed’s height depends on the depth of the water that floods the vegetable garden. The organic matter in the raised bed helps the water move through quickly without drowning plants.
4. Enclose the raised vegetable garden bed
Another option is to enclose your raised vegetable garden. The enclosure may act as a dam and keep water from flowing into the vegetable garden. The bed should be at least 12-inches high and 3 feet wide, but can be deeper. Adding legs to a raised bed makes it waist high, a way to make gardening more accessible for gardeners and eliminate flooding from groundwater.
Fill the raised bed with a high-quality planter’s mix from your local landscape supplier. It sometimes might be sold as garden soil. Recommended ingredients include compost, mushroom compost, black or brown soil, peat moss, bark fines, finely chopped leaves, and other organic matter. These products turn poorly drained soil into well-drained soil.
Give the supplier the dimensions of the raised bed, and they will tell you how many cubic yards of planter’s mix you need. This soil can be used for several years when topped off with fresh organic matter each fall or spring.
Raised vegetable garden not possible?
Sometimes, homeowners associations or municipalities ban raised garden beds. If you don’t want to or are unable to build a raised bed to improve drainage in your vegetable garden, you’ll have to work at the soil surface. It may take two to three years of soil improvements to help drainage at the soil surface. Whether you can plant in that space in the meantime depends on how much surface water continues to flow or stand in that area.
Remember: Avoid digging wet soil, which destroys its structure.
5. Aerate the vegetable garden soil
Once the soil has drained, rent an aerator, which pulls 3-inch plugs from the soil. Or pierce the soil with a garden fork. This allows water and other nutrients to get deeper into the soil, which over time, improves drainage. Throw about 1 inch of compost or other organic matter over the area after aerating or piercing the soil.
As you continue to work at the soil surface, layer in compost, chopped leaves, or other organic material over the area every spring and fall.
6. Grow vegetables in containers
As an alternative to a raised bed, grow vegetables in containers. This likely will eliminate drainage problems in a vegetable garden because the plants aren’t growing in the ground.
Select the appropriate size container for the plants you want to grow (remember to consider their root systems, too). Make sure the container has drainage holes and use a high-quality planter’s mix in the containers.
Why correct vegetable garden drainage?
- Wet soil causes root rot, whether it’s perennials, annuals, vegetables, shrubs, or trees.
- Too much water can drown plants.
- Earthworms and microorganisms essential for soil health are killed in wet soil.
- Standing water can collect algae and other contaminants, causing it to smell bad.
- Working wet soil destroys its structure, which affects drainage, microorganisms, and nutrients.
Yes, there are a few. These include rhubarb, cabbage, mint, cauliflower, and asparagus.
In this case, it’s best to err on the side of caution. You don’t really know what contaminants might be in the water flooding your vegetable garden, so it’s best to pull the plants and dispose of them.
If it’s early enough in the growing season, it may be possible to replant some vegetables once the soil has dried out. Before replanting, add compost or other organic matter to replenish the soil. Avoid digging in wet soil.
• Step one: Dig a hole in the garden 12 inches deep and wide.
• Step two: Fill the hole with water.
• Step three: Fill the hole with water again the next day.
• Step four: The water should drain within eight hours. If it takes any longer, then the soil has a drainage problem.
• Step five: The rate at which the water drains can give you some insight about your soil. If the water drains 4 inches in an hour, the soil is likely sandy. If the water drains less than 1 inch an hour, this could mean the soil is compacted or is heavy clay.
When to call a professional
Explore installing a French drain, drainage pipe, rain garden, or dry creek bed to improve drainage through your property. These can be built to bypass your vegetable garden. A rain garden or dry creek bed would be an attractive permanent fix, possibly allowing you to keep your garden where you have it. And these improvements are environmentally friendly.
When you need help with drainage in your vegetable garden, connect with a local gardening pro. Is your lawn having drainage problems, too? Turn to Lawn Love for aeration services and your other lawn care needs.