Why Are My Grapes So Small?

Grapes are a type of fruit that is grown on vines. Grapes come in all sorts of colors, including green, red, and purple. While grapes can be eaten fresh, they are also used to make wine.

But have you ever looked at your grape vines and wondered why the grapes are so small? Well, you’re not alone. Many gardeners have this same question. In this blog post, we will discuss the climate conditions that are necessary for grape vines to produce large, juicy grapes. We will also provide tips on how to create the perfect environment for your grape vines!

Why Are My Grapes So Small?

Underwatering, over-fertilization, poor pruning, and lack of weeding can all contribute to small grapes. Just one of these factors can limit the size of your grapes, so it’s important to address all of them if you want to see an improvement.

I will now go into more detail about each of these factors so that you can make the necessary changes in your own grape-growing operation.

1. Lack of Water

Just like all plants, grape vines need water to survive. However, grape vines are especially susceptible to drought stress. When the soil around your grapevine is too dry, the plant will start to shut down and will not produce grapes.

Make sure that you are watering your grape vines regularly and deeply. Deep watering means that you should water the roots of the plant, not just the leaves. The best way to water grape vines is with a soaker hose or drip irrigation system. These methods will ensure that your plants are getting the water they need without wetting the leaves, which can lead to fungal diseases.

Young grapes need around 1 inch of water per week. If you live in an area with hot summers, you may need to water your grape vines twice a day to prevent them from drying out. Make sure to check the soil around your plants regularly so that you can tell when they need water.

Make sure drainage is good in the area where you are growing your grape vines. If the soil does not drain well, the roots of your plants will start to rot. This can lead to a number of problems, including the death of your grape vines.

2. Over-fertilization

While grape vines do need nutrients to grow, too much fertilizer can actually be harmful. When you over-fertilize your grape vines, the plants will produce more leaves and stems than grapes. This can lead to a smaller crop overall.

To reduce the risk of over-fertilization, only fertilize your grape vines when they are actively growing. This typically happens in the spring and early summer. Avoid fertilizing your plants in late summer or fall, as this can encourage new growth that is susceptible to frost damage.

When you do fertilize your grape vines, use a balanced fertilizer that is specifically formulated for grapes. Do not use a fertilizer with too much nitrogen, as this can burn the roots of your plants.

It is also important to test the soil before you fertilize. This will help you determine which nutrients your grape vines are lacking so that you can add the right fertilizer. A soil test kit can be purchased at your local garden center.

small grapes
A handful of small grapes

3. Poor Pruning

Annual pruning is required to reduce the amount of fruiting canes on the plant. you see, the yield will suffer if too many canes are left on the grapevine, so get rid of about 90% of the last season’s growth. This may seem like a lot, but trust me, it’s necessary for optimal grape production.

In addition to reducing the number of fruiting canes, pruning also helps to improve air circulation and sunlight exposure. These factors are important for preventing fungal diseases and ensuring the grapes get the sunlight they need to ripen properly.

If you are new to grape growing, I recommend having a professional come and prune your vines for the first year or two. This will help you get a feel for how much to prune and when to do it. After that, you can start doing it yourself.

Pruning grape vines may seem like a lot of work, but it is essential for getting a good crop. Make sure to prune your plants regularly to ensure the best possible results. Cane pruning and spur pruning are the two main types of pruning for grape vines.

4. Lack of Weeding

Weeds compete with grape vines for water, nutrients, and sunlight. This can lead to smaller grapes and a reduced overall crop. Just think about it: if the weeds are taking up space and resources that could be used by the grape vines, the grapes will suffer.

Having plants growing under your vines also makes the soil cooler, which can lead to problems with grape growth in terms of size and quantity.

To prevent this from happening, make sure to remove any weeds that you see around your grape vines. You can do this by hand or with a hoe. Be careful not to damage the roots of the grape vines when you are weeding, as this can harm the plants.

Weeding may seem like a tedious task, but it is essential for getting a good grape crop. Make sure to remove any weeds that you see around your vines so that they can grow and produce fruit properly.

Can My Grapes Grow after the Initial Growth Period?

No, once the initial growth period is over, your grapes will not grow any larger. This is because the grape vines have reached their full size and are no longer actively growing.

This highlights the importance of proper grape vine care from the start. If you want to grow large, healthy grapes, you need to provide the plants with everything they need to thrive. This includes proper fertilizer, pruning, and weed control.

How Do I Know If My Grapes Are Ripe?

It can be tricky to determine when grapes are ripe, as they can vary in sweetness and color depending on the variety. A good way to test for ripeness is to gently press the grape with your thumb – if it yields to pressure, it’s likely ripe. Additionally, look for grapes that are mostly a uniform color (with just a touch of green remaining), and that have a sweet aroma.

If you’re not sure whether or not your grapes are ripe, it’s best to taste them – but be careful, as some grapes can be quite sour even when ripe.


In conclusion, the four main reasons why your grapes might be small are lack of water, over-fertilization, poor pruning, and lack of weeding. Make sure to address these issues if you want to grow healthy grape vines that produce a good crop.

Simply put, the better you care for your grape vines, the more grapes you will get. So, make sure to give your plants the attention they need and you will be rewarded with a bountiful harvest.

Do you have any tips for growing grapes? I would love to hear them in the comments section below. Thanks for reading!

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