As a family we love going on picnics, and we regularly have them in the garden too. Essential to this whole process is a good picnic rug – but are they fully waterproof when it comes to sitting on potentially wet ground?

Most picnic rugs have a waterproof backing made of polyester, coated with a waterproof layer made of polyurethane. This makes picnic blankets 100% waterproof. Be careful not to buy a rug that’s only water-resistant though, as you could end up with a wet bottom. 🙂

Let’s ‘unpack the picnic basket’ on this subject and discover more about the waterproofing characteristics of picnic blankets, how to wash and dry them – and even how to make one if you’re feeling creative. Just remember to keep your eyes peeled for those hungry bears Yogi and Boo Boo!

Are Outdoor Blankets Really Waterproof?

Yes – really, really. It’s because there are two layers – a 100% waterproof one that you lay on the wet grass and a colorful and cozy layer that you sit on.

Most picnic blankets have a waterproof backing made of polyester, coated with a waterproof layer like polyurethane. That makes the blankets 100% waterproof. Reviewers have described using the blankets as a rain shield in a sudden downpour at the concert, in the mountains, or at the game.

Some manufacturers describe their blankets as water-resistant – not waterproof. Be careful, as these may leave you with a wet booty. Water resistant blankets may have a factory-applied sealant to make them waterproof at first, but sealants wear off. 

If you just can’t resist that particular water-resistant blanket, be prepared to renew the seal every year.

We love rocks and love to picnic in rocky places. If you’ve got rocks, some blankets have three layers – a waterproof one, a squishy padded one, and then a soft fleecy one.

Most blankets fold onto themselves and have a stuff sack or handle to make them super portable. If you live in a cold climate, there are blankets that have a reflective, emergency blanket-type. 

Some blankets come with weights at the edges for breezy beaches. Others have corner loops sewn in so you can stake it down if the wind comes up.

How Do You Wash a Picnic Rug?

Most picnic blankets are machine washable because they expect you to go outside with your kids, your dogs, your friends, plenty of beer and lots of food.

Be sure to check the instructions. Sometimes the waterproof layers don’t do well in a machine, so you’ll need to choose the gentle/hand wash cycle. Then, if the instructions allow it, pop it in the dryer on gentle. Otherwise, hang it up.

Very few picnic rugs require hand washing due to their delicacy. Some are too big for small washing machines, though. For giant picnic rugs, start with wiping off the spillage and mud. If it’s still nasty, get the hose out.

Drape the blanket over a fence or a few chairs and hose it down. Then let it dry in the sunshine and breeze. Consider treating large size blankets with a stain-resistant spray.

Try to avoid storing a damp picnic rug. If possible, hang it from a tree or your car door to dry. If you must pack it up wet, don’t forget to spread it out later on a sunny day. If your picnic rug develops some black spots – mold and mildew – then use some bicarbonate soda and dish washing soap to sponge the spots. 

A vinegar solution will work on mold and mildew too. The smell of vinegar will go away quickly, but you can spritz your blanket with a water and essential oil solution. Try oil of cloves, cinnamon, peppermint, or lemon.

How Long Do Picnic Rugs Take To Dry? (Will They Go in a Dryer?)

Many will go in the dryer, but some recommend hanging them to dry instead. Make sure the waterproof backing is OK in a dryer, and then use a low setting.

Be careful you don’t get a cold, wet surprise when you take a waterproof blanket out of the washing machine.

How Do You Make a Waterproof Fleece Picnic Blanket?

We love tassels. This description is for a tasseled, two-sided picnic blanket.

What you’ll need:

• Sewing machine.
• Scissors.
• Marking pencil or chalk.
• Measuring tape.
• Skein of yarn for tassels.
• Waterproof fabric – make sure it’s not too crinkly (which can be annoying) and totally washable. If you like to picnic on rocks, find a fabric that is slightly padded.
• Soft, fleecy fabric – find some that will wash stains (like food) out well, like “performance” fleece. Choose a fleece that doesn’t unravel and has minimal stretch.
• Thread.
• Iron and ironing board or steamer.

Directions for a DIY tasseled picnic blanket:

1. Measure out your blanket and cut your fabric.
2. Decide how many tassels you need. Tassels can go on opposite sides or all sides, and from 2 inches apart to 6 inches apart.
3. Make the tassels. First, cut two pieces of yarn about 10 inches long and set them aside.
4. Using the skein of yarn, hold the end of the yarn with your thumb. Then wrap the yarn loosely around the palm of your hand up to 20 times. With your other hand, slide the yarn off your hand, keeping hold of the circle of yarn in the middle. Cut the circle from the skein. 
5. Loop one piece of 10-inch yarn through the middle of the circle of yarn, then out the other side and tie it with a square knot. You should be able to let go of the circle now and dangle the circle from the ends of the 10-inch piece.
6. While dangling the circle of yarn in one hand, grab it with the other hand and pull the circle closed so all the yarn is hanging in a line.
7. Tie the second 10-inch piece around the 40 strands of yarn, about a half inch from the first 10-inch tie. Make a square knot tight around the strands.
8. Cut the ends of the looped yarn and then trim the tassel. Here’s a website with photos and other ways to make easy tassels.
9. Repeat for all the tassels.
10. Put the pieces of the fabric together, right sides together.
11. Mark the edges of the fabric where you want the tassels to go.
12. Pin the tassels in place. Put the tassels on the inside of the fabric, next to the right sides. The body of the tassel should be from 1/2 inch to 1 inch from the seam. You should not sew through the body of the tassel, only the 10-inch tie. Looking at the wrong sides of the fabric, all you should see are the ends of the 10-inch yarn ties sticking out slightly – a quarter inch. Try a test run with pins, turning the fabric to the right side. When you have the right sides out, the tassel should be dangling down from the edge by a half inch to an inch.
13. After pinning all the tassels in place, sew the seams. Standard seams are 5/8 inch. 
14. Sew all the seams except for a gap on one side of at least a foot. You will need the gap to turn the fabric right side out.
15. Trim the edges to around 1/2 inch, particularly on the corners.
16. Turn the fabric right side out through the gap in one side.
17. For the gap, fold the edges in 5/8 inches, then pin the sides together. Pin some tassels in if your design calls for them. Steam or iron the gap.
18. Steam or iron the entire blanket so all the edges are clean, and the corners are sharp.
19. Sew 1/2 inch around the entire blanket, on the top side. This final stitching can be decorative. You can set the stitches to a long length and change the thread to a bright color. Do a double line of stitches or use a zigzag stitch. Consider stitching on some ribbon or tape. This final stitching should secure the gap and its tassels too.

You can buy a stuff sack for your blanket so you can carry it around or throw it in the back of the car.

Where Can I Buy Waterproof & Washable Picnic Rugs?

There are lots of waterproof, washable picnic rugs available online and in stores. Try Amazon, L.L. Bean, Walmart, Pottery Barn, Target, and Bed Bath & Beyond.

Final Words

If you love picnics as much as our family does – or if you’re a certain cartoon bear called Yogi – then a waterproof rug is as important as a ‘picnic basket’ when it comes to eating outside in the yard or further afield.

Just be careful not to buy a picnic blanket that’s merely water-resistant – as that could end up with you getting a wet Boo Boo. And the ranger ain’t gonna like that!