How to Build a Small Pond for the Garden

Tips on how to build a small pond to attract frogs and other wildlife into the garden. Includes information on placement, size, materials, and maintenance.

Ponds are beautiful garden features but building one for your growing space can be practical too. They attract and support local wildlife, can create a natural place to store water, and can even help with pest control. We all know that organic gardening can be difficult, especially when it comes to slugs. You can pick them off individually, set out beer traps and pelleted wool, but most people resort to slug pellets. They’re just so much easier and more successful to use. Unfortunately, they can be fatal to pets and to wildlife like hedgehogs and songbirds. There’s another way to help tackle the slug problem more naturally — build a small garden pond. Build it and frogs will come.

A garden pond attracts all kinds of wildlife and especially the type that likes eating slugs. Frogs are voracious hunters of insects, including weevils, and they’ll devour the slugs in your garden too. It’s also a lot of fun to watch them swimming around and filling the garden with life. They don’t eat any of your veggies either. Ponds give frogs a place to raise their young, a moist habitat that they like, and some frogs will even overwinter in ponds. In return for giving them a place to live, they’ll help you with natural pest control.

Building a Small Garden Pond

I built the pond you’ll see in this DIY idea three years ago. Since then it’s become one of the most important features in my garden. Every year around Valentine’s day it fills with frog spawn (eggs), and over the weeks becomes a medley of tiny tadpoles, water snails, and other water creatures. Most have moved in on their own.

My latest addition to the pond is a small solar fountain that has been happily aerating the water for the past few months. Because I don’t have an electric source, it’s the best option I could think of to replace a pump. I still have to manually pull out pondweed but to be honest, the pond is a wonderful living structure that fills my garden with life. If you want to see regular updates and videos of the pond as it is now, watch the garden tours I publish on my YouTube channel.

Ponds are a Haven for Wildlife

The idea for a wildlife pond came to me as I was tidying up a flower border. I accidentally disturbed a large frog and then helped herd him into the hedge. I don’t know why I was surprised to see him there as there was a basin of water nearby that had been there all summer. That eureka moment helped spur the idea to build a purpose-built frog pond in the vegetable garden.

I’ll be sharing how I built mine a bit further on but want to share the most exciting bit of news. There were frogs in my pond just a few months after building it. They find it on their own in most cases and all you have to do is build one and wait. You can also bring frog spawn to your pond and help jump-start the colonization process!

Lessons Learned When Building a Pond

I’m sharing this project several years on from when I built the pond. That first year I used an old piece of plastic sheeting for the lining and unfortunately, it sprung a puncture that first summer. I replaced it a year after the initial build with proper underlay and a durable pond liner. Stones from both underneath and on top of the liner can puncture it, especially if the “liner” isn’t built for purpose.

Since re-building the pond with the correct materials the pond has been a stunning little jewel in my vegetable garden. I have tadpoles and frogs in it every year, birds come to drink from it, and my honeybees come down for a sip too. I honestly couldn’t recommend any other feature to put in a veggie patch than a small wildlife pond.

Where to Build a Small Pond

You can create one at any time of the year but I think it’s a great project for late winter and early spring. First of all, you’ll need to choose the location of where to situate your pond. It should have a good amount of sunlight (4-6 hours a day), and preferably in a flat area in the garden. Keep it away from trees since their leaves will become a nuisance in the water. Not to mention their roots when you’re trying to dig the pond out.

You should also take precautions if you have small children or a social area nearby. If you have little ones, they’ll naturally be curious about the pond. Any kind of water can be dangerous though so make sure it’s fenced off.

Avoid Mosquito Issues in Your Small Pond

Depending on your area, ponds could be a place where mosquitoes can breed. If you’re worried about this, there are a few things that you can do to reduce their numbers. Keep the water moving, and I can recommend the solar fountain that I use. Mosquito larva feeds off pondweeds, so keep your pond cleaned of overgrowth by manually pulling or scooping it out. Wildlife ponds, opposed to chemically treated ponds, are filled with predators of mosquito larva too! Tadpoles and even fish will eat both eggs and larva. Lastly, keep the pond away from your seating area and deck to minimize bites.

Wildlife Pond Sizes and Depths

Size does matter when it comes to ponds. They should be deep enough for fish and frogs to hide from predators and shallow enough for aquatic plants. If you live in a cold area, you may need a deeper pond to stop it from freezing solid. Something to really take into consideration for frogs and fish.

Small garden ponds tend to have two to three depths — shallower areas to put plants, and a deeper area for animals to hide in. The shallow area for plants is generally a foot deep and the rest of the pond is 2-3 feet deep. If your winters are very cold, consider making the deepest part of your pond 3-4 feet deep.

Because you need to accommodate varying depths, the width of a pond should be at least three feet. More is better though and my own is four feet in diameter.

Planning the Pond Site

It’s pretty easy to build your own wildlife pond. First, make an outline on the ground where you’re planning on building it. Use string or a sprinkling of flour or cornmeal for an eco-friendly solution. Imagine where the shallow areas and deeper areas will be. Most people choose to have the deeper area in the middle of the pond. That makes it safer for children who might visit and also creates a safe little nook for wildlife to hide from birds and other predators.

Materials for a Small Garden Pond

Once you’re happy with the siting and size it’s time to assemble materials and begin building the pond. These are the materials you’ll need to build a small garden pond:

• A spade and/or shovel
• Underlay
• Pond liner
• Aquatic plants
• Solar pond pump or fountain
• Netting or fencing (to keep children or pets out)

Build a Small Garden Pond

After your materials are readied, get your spade and earthmover out and start work. Dig your pond so the edges gradually taper down, if possible. Your pond will need an access area for frogs and other creatures to get in and out. A natural slope from the water’s edge is the best solution. You can also create ramps inside the pond itself and my pond has a large stone that angles up from the pond to the edge. Tadpoles LOVE this stone in spring and I see them hanging out against it right under the water. It must be much warmer than other areas of the pond!

Digging a pond will leave you with a considerable heap of soil. You can use it in the garden somewhere, perhaps in a new garden bed. Alternatively, you could use it to build up one side of your pond if you’re on a slight slope.

Line the Pond Hole with Underlay and a Liner

After the hole is dug, make sure there aren’t any stones or sharp objects that could puncture the lining. Next stamp the ground down to create a firm surface. Spread the underlay layer over the hole. This soft material gives extra support to the pond liner and reduces the chances of punctures. Unfold the pond liner and lay it over the top so that its edges overlap by a good foot or two. Don’t trim the edges until the very end of this project as the liner will need to settle after you fill the pond with water. Try to smooth the plastic liner out but don’t worry if it looks wrinkly since it will sort itself out in the next step.

All of the ponds I’ve ever created have been on slopes. My small garden pond in the allotment, the large pond at the allotment, and the new pond that I’m about to dig at home. I don’t know what it’s like to have a flat garden space! In this case, you can use the soil you dig out to help build up the lower side. I also used a wooden garden bed to help create the sides of my small garden pond. I wrapped the wooden frame in plastic before laying the underlay and pond liner on top. Alternatively, you can invest in a preformed pond liner and it will do the job for you.

Fill the Pond with Water

You should have the hole dug and lined now and ready to become a pond. Fill it with water from the hose, and you’ll be amazed to see how the liner forms to the hole you’ve made. It’s mesmerizing watching the space fill with water too! After it’s full, the next step is waiting 48 hours for the pond to settle and for the chlorine in the water to evaporate out. After this time you can trim the edges of the plastic liner and outline the pond with stones and/or pebbles. You may also want to dig the edges of the pond liner into the ground.

Add Plants and Water Features

You can also fill the pond with features and plants now. Garden soil has a lot of nutrients in it and it will contribute to pondweed and algae infestations. Instead, use poor-quality subsoil, sand, or gravel to create a layer for plants to grow in. You can also place larger stones in the pond, but ensure that they don’t have sharp edges that could puncture the liner.

Aquatic plants can go in next and the ones I have in my pond are flag irises, a papyrus, and a marsh marigold. There are lots of choices though. Many pond plants will come in baskets that you can float in the water or weigh down at the margins.

Small Pond Maintenance

Even if you have a water pump installed, your pond will need maintenance. Birds that visit will bring in pondweed on their feet and it will colonize your pond too. Leaves and other material will fall in the water too, rotting and depriving the water of oxygen.

With my small pond, I tend to clean it a little throughout the year. I’ll reach in to pull out blanket weed or skim the surface to remove a lot of the duckweed. I set it at the pond’s edge for a few days before putting it in the compost pile. This gives time for aquatic animals to find their way back into the pond.

The best time to do a full pond clean is in autumn. It’s after a lot of the leaves on nearby trees have fallen but before animals have gone dormant in the lower levels of the pond. Pull excess leaves and muck from the bottom and bail some of the water out with other pond scum.

When you’re refilling the pond, do it gradually and with safe water. It could be from rain barrels or from containers filled and left out for at least a couple of days. When you initially fill the pond there’s nothing alive inside it. However, once the pond is established, avoid using tap water in the pond. The chlorine in it can kill frogs and other pond creatures.

Small Garden Pond Ideas and Inspiration

Building a small garden pond in the garden has been the BEST feature I’ve ever added. It looks beautiful, creates a home for wildlife, and since building it I’ve seen a reduction in the number of large slugs and snails. Every garden should have a pond, in my opinion, but even a small container of water set in the ground can work as a pond. Here’s even more inspiration for adding water and water features to your growing space:

• Building a Large Garden Pond
• Make DIY Ollas — self watering pots for the garden
• Creative Garden Ideas for RAIN