Is It Safe to Feed Your Crested Gecko Grapes?

Last Updated: January 25, 2023

Being a good pet lizard person includes feeding your pet a healthy and balanced diet. There are a lot of healthy, safe fruits crested geckos can eat, but some are dangerous. What about grapes? Can crested geckos eat grapes? Are they a good choice or something you should avoid?

People have cultivated grapes for thousands of years. Today we enjoy them fresh, dried, in juice, and as wine. They are full of nutrients that offer many health benefits.

Humans love them, but what about lizards? Should crested geckos eat grapes?

Yes, crested geckos can eat grapes occasionally. Grapes are nutritious but can disrupt their calcium levels. They can be a safe part of a balanced diet.

Crested geckos are frugivores that eat insects, fruit, and nectar in the wild. But each type of fruit is different, and it is necessary to understand the specifics before taking a risk with your pet.

Many keepers need answers before they start serving grapes to their crested gecko. How many grapes are enough? Do I need to peel the skin off first? Can I mix grapes with something else for a healthier option?

These are vital questions to ask before feeding your pet something new.

We know not all fruits are suitable for crested geckos. Why are grapes acceptable? Keep reading to learn the pros and cons of serving grapes to your beloved pet!

A hatchling crestie rests on a bunch of red seedless grapes staring at the viewer.

Do Crested Geckos Eat Grapes in The Wild?

Grapes have been grown and enjoyed by humans for thousands of years. Their cultivation originated in the Middle East. Accounts of wine are prevalent in ancient Egypt, Greece, and Rome.

Today, they are eaten fresh, dried, as wine, and in unfermented juice.

Did you know that there are over 10,000 different varieties of grapes in the world? The ellipsoid-shaped fruit comes in nearly every color and a wide range of flavors. Some are sweet, while others are bitter.

Grapes grow on the vines of the plant Vitis vinifera in bunches of 15 to 300.

Different countries prefer distinct breeds of grapes. The Kyoho is the most-grown grape variety in the world and is enjoyed widely in China. The Thompson Seedless, or Sultana, is the most common grape in the United States and Australia.

But what about cresties?

Crested geckos live on three islands in New Caledonia, located 750 miles (or 1,200 kilometers) from Australia. While there are many native fruits on these islands, the grapes we are familiar with are not among them.

Even though it is unlikely that a wild crested gecko has ever tasted a grape, it doesn’t necessarily mean they are not safe for it to eat.

Let’s look at the pros and cons of grapes to learn more.

A crestie sits on a cluster of grapes, wondering "can crested geckos eat grapes?"

Nutritional Value

Grapes contain several helpful nutrients that may benefit health.

The nutrients in red seedless grapes, calculated by a standard serving of 3.5 ounces (or 100 grams), are:

  • Calories: 86
  • Water: 78%
  • Protein: 0.91 g
  • Carbohydrates: 20.2 g
  • Sugar: 17.3 g
  • Fat: 0.16 g
  • Calcium (Ca): 10 mg
  • Phosphorous (P): 25 mg
  • Iron (Fe): 0.16 mg
  • Magnesium (Mg): 8.6 mg
  • Potassium (K): 229 mg
  • Sodium (Na): 7 mg
  • Zinc (Zn): 0.04 mg
  • Copper (Cu): 0.081 mg
  • Manganese (Mn): 0.098 mg
  • Vitamin C (total ascorbic acid): 3.3 mg

Grapes are a good source of antioxidants (compounds that help repair your cells) and a moderate amount of vitamin K.

These tiny fruits also contain vitamin C and beta-carotene, which may protect against chronic health conditions.

Eating grapes may be beneficial to bone health. A study on grape-fed rats had improved bone quality compared to the control group.

Not all research on animals eating grapes is positive.

One study examined the effect of tourists feeding grapes to wild rock iguanas in the Bahamas. The grapes are higher in sugar than the iguana’s natural diet, creating health concerns. While crested geckos and rock iguanas are different, it is an indicator of overfeeding a sweet fruit like grapes to a lizard.

In moderation, grapes are a healthy addition to a diet.

Are Grapes Good or Bad for Crested Geckos?

Unfortunately, there aren’t extensive studies on the health impact of feeding grapes to crested geckos.

Where do we go from there? We need to look closely at the amount of calcium, phosphorous, and oxalic acid they contain.

A frog-butt crested gecko climbs excitedly with each of his front feet on different grapes.

What Is the Calcium-Phosphorous Ratio?

All reptiles, including crested geckos, need calcium (Ca).

Calcium is critical for healthy bones. It also regulates important heart, nerve, and blood functions.

A body gets calcium either from food or by removing it from its bones. In this way, bones serve as a “savings account.” Frequent withdrawals will leave the body without enough of this essential mineral to function.

Many pet reptiles do not get enough calcium from their diet, which leads to a common condition called Metabolic Bone Disease (MBD).

Another factor for MBD is phosphorous. Phosphorous inhibits calcium absorption. When the body can’t use all of the calcium in the food, it only has one other source.

Unfortunately, both Ca and P are present in many fruits and vegetables. Getting the right amounts of each isn’t easy.

The ideal calcium-to-phosphorous ratio for reptiles is 2:1. This means there should be twice as much Ca as P in every bite.

Grapes have 10 milligrams of calcium and 25 milligrams of phosphorous. That isn’t enough calcium compared to the amount of phosphorous. It’s barely one-quarter of what we would need!

From this perspective, grapes are not healthy for crested geckos. They might be harmful in large quantities.

Calcium-to-Phosphorous Ratio

Grapes have a 0.4:1 Ca:P ratio, which is bad. 

Oxalic Acid Content

Oxalic acid is another compound that also interferes with calcium. Unfortunately, there is no ideal ratio for oxalic acid. We want to keep the oxalic acid content as low as possible.

Good news! Both red and green seedless grapes are very low in oxalate, with only 1 milligram per half cup.

So, Are They Good or Bad?

Grapes are fine for cresties as a once-in-a-while goodie.

While they have a poor calcium-to-phosphorous ratio, they have other nutrients and are low in oxalates. We can consider grapes a monthly treat at most.

For many keepers, it is helpful to compare this to ‘desserts’ for humans. If desserts made up a large portion of what you ate instead of a balanced diet of fruits, vegetables, grains, and proteins, it would make you ill. An every-once-in-a-while treat isn’t a problem.

A young flame pinstripe crested gecko sticks his nose under a grape.

Feeding Instructions

What Is the right portion size?

The amount of food to give to a crested gecko is relative to the size of the lizard. The amount of fruit offered should also use this approach.

Compare a 1/8 teaspoon, 1/4 teaspoon, and a 1/2 teaspoon to the space between the crested geckos’ eyes. Notice which teaspoon is the same size or a bit smaller. That teaspoon is one serving of fruit for that animal.

How often can I serve grapes?

Grapes are a treat.

Ideally, your pet should primarily eat powdered gecko food with some live feeder insects and occasional fruit. Together, this will provide all the vitamins and minerals your pet needs.

Following this approach, you can feed your crested gecko grapes once a month at most.

Remember, offering a variety of fruits is essential to providing all the nutrients your crested gecko needs, even if they like one the best!

How do I prepare and offer grapes?

Crested geckos don’t use their teeth to bite and chew their food- they use their tongues!

Any solid food provided to a crestie should be offered in small enough pieces to be easily swallowed and digested.

Softer, overripe – even slightly spoiled – is ok. In the wild, crested geckos eat fruit that has fallen to the ground after ripening. Overripe fruit is natural for them.

Preparation

First, wash the grapes to remove any pesticides or bacteria. You can use a fruit and vegetable wash to break down the chemicals, wax, and residue covering them. Rub it with the produce cleaner under cold water and then pat it dry.

The two best ways to prepare grapes are pureeing and slicing. Both are easy to prepare, but the mashed puree is better if you want to mix grapes with commercial gecko diet powder. This approach leverages the sweetness of the fruit with a better calcium-to-phosphorous ratio, making it a healthier option for your pet.

If you prefer a knife, slice the grapes into tiny pieces. Each piece should be smaller than the space between the crested gecko’s eyes.

Should you serve grapes with or without the skin?

Eating the skin of a grape isn’t a health problem for crested geckos. The skins are nutritious, so include them if possible.

The outside does taste different from the inside, so your pet may prefer one or the other.

If you slice up a grape, keep the portions of skin as small as the flesh. If you choose to puree, remove any large pieces that weren’t cut up. We never want to serve food that could be a choking hazard.

Can I mix mashed grapes with something else?

Yes! Grapes contain healthy nutrients but aren’t a ‘perfect food’ for crested geckos. Mixing them with something else can offset the problems.

Commercial gecko diet, papaya, and figs are all solid choices because they are higher in calcium than phosphorous, which helps balance out the downside of grapes.

You can blend grapes with insects, like crickets or dubia roaches, or another fruit, like strawberries, but these mixtures will continue to have high phosphorous content. Only do this once a month and not multiple months in a row.

A crested gecko is about to fall off a pile of grapes as it moves towards the camera.

Buying and Storing Grapes

What is the best month to buy them?

The best time to buy grapes is when they are in season. In the US, that is in August, September, and October.

In-season grapes travel shorter distances than their off-season equivalents, so they are fresher when they get to you. As with all produce, the less time between harvest and purchase, the better the taste.

While many stores will carry grapes year-round, they cost more and don’t taste as good in the off-season.

How do I pick the best grapes?

Ripe grapes are firm, plump, well-colored, and firmly attached to the stem. Avoid bunches with fruit that is soft and mushy.

How long do they keep?

If refrigerated, grapes stay fresh for about two weeks. Store them in a well-ventilated container in the crisper drawer for maximum freshness. They only last for 2-4 days at room temperature.

Should I buy organic or conventionally grown grapes?

Studies have shown organic grapes look better, taste better, and are healthier than conventionally-grown grapes. In addition, grapes have higher levels of pesticide residue.

Lizards are sensitive to chemicals and pesticides. Eating contaminated fruits can make them sick.

Offering organic grapes to your crested gecko reduces its exposure to potentially harmful chemicals, which is a safe choice.

Do All Crested Geckos Like Grapes?

A smiling profile of a crested gecko climbing a bunch of red grapes.

Just like with humans, each crested gecko has preferences. Not every person likes the taste of grapes, nor does every crestie.

Grapes are not on the list of the favorite foods for cresties.

Do you remember a time you tried a new food? Maybe you took only a little taste and then stopped and tried again later. Just like humans, crested geckos need to warm up to new things.

If you’ve offered a grape to your pet and they didn’t devour every bite the first time, don’t worry. Try offering them a few times, maybe blended with other fruits your pet regularly eats to help them adjust to the taste.

Conclusion

Crested geckos can eat grapes periodically, up to once a month.

While they have an undesirable calcium-to-phosphorous ratio, grapes’ low oxalic acid and high vitamin K content are good. Because they aren’t as sweet as strawberries or watermelon, cresties aren’t likely to be quite as excited for this treat.

Still, mashed and mixed with powdered gecko diet will be an enjoyable surprise.

If they are something your crested gecko enjoys, grapes can be part of a diet that helps them live a long, healthy life.

A tiny crested gecko sits on top of a stem of grapes.

What about other fruits? Can Crested Geckos Eat Kiwi Fruit?