Fertilizer Side Dressing the Vegetable Garden, Fully Explained

by Jennifer Poindexter

When reading through posts on the internet, have you heard people discuss side dressing plants? Are you sure what this means or how to perform this act successfully? You’ve come to the right place. I’m going to fill you in on what it means to side dress your plants. I’ll also provide tips to help you side dress plants properly. 

There are certain plants which thrive from this process when receiving fertilizer on a regular basis. Other plants don’t require this process at all. I’ll fill you in on a few general rules when figuring out which plants love side dressing and which don’t.

If you’re into gardening and want to learn all there is to know about growing healthy and fruitful crops, here’s what you should know to side dress your plants properly.

What Is Side Dressing Plants?

Side dressing plants is exactly what it sounds like. You’ll use fertilizer and apply it to the side of the plant.

It should be applied at the base. However, you don’t want to apply it right at the stem. Instead, you should move approximately six inches away from the stem before applying.

This puts the fertilizer in position to feed the plant without scorching it. Side dressing is particularly important for low-quality soil that struggles to hang on to nutrients.

By applying nutrients, as needed, it allows crops to grow while poor soil is being amended. Side dressing should be a continued act of maintenance for your garden even after the soil quality improves. It’s a wonderful way to replenish necessary nutrients.

Understanding what the term, side dressing, means is only the beginning of this gardening maintenance journey.

How to Side Dress Plants

Once you understand what side dressing is, it’s time to learn how to properly perform this task. You start by understanding the needs of each of your plants.

Some plants are heavy feeders while other plants thrive from neglect. It’s vital to understand which category each of your plants fall under. Plants that are heavy feeders should be fertilized on a frequent and regular basis. Plants which thrive from neglect, may need their nutrients supplied during the planting process. After this time, they’ll most likely prefer to be left alone.

Perform research to ensure you understand how frequently your plants must be fertilized, because not all vegetables have the same needs. In your research, understand which nutrients the plants need as well. The importance of this information is equal when raising crops. 

In most cases, plants lack nitrogen. Every plant needs nitrogen to grow properly. Therefore, there never seems to be enough in any planting area. When you know the timing for applying fertilizer and which nutrients must be added, use a granular fertilizer for side dressing. You may also use compost.

It isn’t advised to use liquid fertilizer, as you have less control to where the fertilizer ends up around the plant. Granular fertilizer and compost give you more control during the application process. If the plants are planted in a row, apply the fertilizer to the side of the stems as you walk down the row. Again, ensure you apply the fertilizer approximately six inches away from the base of the plant.

For larger plants, you can apply a circle of fertilizer around the base of the plant. This works well for tomato and pepper plants because they’re spaced further apart than smaller plants. Remember to place the fertilizer six inches away from the stem to avoid harming the crop. 

Now that you know how to side dress your plants, let’s discuss what you should use in greater detail.

What You Should Use to Side Dress Plants

There are multiple things you can use to side dress your plants. Using a balanced granular fertilizer is a great choice for most crops. It even works on root vegetables.

When applying a granular fertilizer, be sure to use a rake to mix it into the soil prior to watering the plants. This will avoid any clumps being pushed too close to your crops.

Compost is another great option for fertilizer. Be sure to apply it in a row or a circle, depending upon your plants. With compost, be careful to only use fully finished compost that isn’t still generating heat. If the compost is still breaking down, it can harm your plants.

You’ll want to water after the compost application. It’s a wonderful source of nitrogen and works as any other fertilizer would.

When fertilizing leafy greens, fish emulsion is a wonderful option. It’s also high in nitrogen, but it works faster than other fertilizer options.

As we’ve already, briefly, discussed, it isn’t recommended to use liquid fertilizer for side dressing. In liquid form, it’s difficult to see where the fertilizer is being applied.

Therefore, granular fertilizer or compost are typically best when using this method to fertilize your crops.

You now understand what you should use to side dress plants properly. Now, it’s time to discuss when most plants need to be side dressed.

Which Plants in Your Garden Might Need Side Dressing?

As we’ve discussed, side dressing is an essential gardening practice for many plants, providing them with the much-needed nutrients at critical points in their growth cycle. By applying fertilizer to the side of a plant, you are making sure that the nutrients are easily accessible for absorption.

Certain plants are particularly heavy feeders, meaning they require extra nutrients throughout their growth in order to achieve optimal health and yield. Now we’ll take a look at some plants that benefit from side dressing, along with some brief details on their specific requirements:

• Tomatoes: These plants are heavy feeders and require consistent nutrient supply. Side dress with a balanced fertilizer when they begin to set fruit and then every 4-6 weeks thereafter. You can also use a high-phosphorus fertilizer to promote fruit development.
• Peppers: Like tomatoes, peppers are also heavy feeders. Side dress them with a balanced fertilizer when they begin to flower and then every 4-6 weeks throughout the growing season.
• Corn: Corn requires a significant amount of nitrogen during its growth. Side dress with a high-nitrogen fertilizer when the plants are about knee-high and again when tassels begin to emerge.
• Squash: Both summer and winter squash varieties benefit from side dressing. Apply a balanced fertilizer when plants begin to flower and then every 3-4 weeks throughout the growing season.
• Cucumbers: These plants need consistent nutrients to produce a good yield. Side dress with a balanced fertilizer when they start to flower and then every 3-4 weeks during the growing season.
• Broccoli: Side dress broccoli with a high-nitrogen fertilizer when the plants are about halfway to their full size, and then again after you harvest the main head to promote the growth of side shoots.
• Cabbage: Apply a high-nitrogen fertilizer when the plants are about half their final size and then again after the heads begin to form.
• Collard greens: These leafy greens need consistent nitrogen supply for optimal growth. Side dress with a high-nitrogen fertilizer every 4-6 weeks during the growing season.
• Kale: Similar to collard greens, kale benefits from a high-nitrogen fertilizer applied every 4-6 weeks throughout the growing season.
• Onions: Side dress onions with a balanced fertilizer when they are about pencil-thick and then again 3-4 weeks later to support bulb development.

By side dressing these plants at the appropriate times, you can help ensure their healthy growth and development, leading to a more successful and productive garden.

Plants that Don’t Need Side Dressing

Not every plant in your vegetable garden needs side dressing. You don’t need to do it with these plants.

• Green beans
• Radishes
• Peas
• Beets
• Carrots
• Lettuce
• Spinach

Keep in mind that these plants may still benefit from an initial application of fertilizer during planting, but they typically don’t need extra side dressing throughout their growth cycle. Always research the specific requirements of each plant variety you’re growing to ensure you’re providing the proper care.

When to Side Dress Most Plants

I told you, previously, to research your plants. This will help you understand when each variety needs to be fertilized and if there’s a time when the plant could benefit from applying one nutrient more so than another.

However, balance is important in the overall scheme of fertilizing throughout the growing season. We’ll discuss this further in the next section.

If you’re ever unsure of when you should side dress a crop, there’s a general rule that works for most plants.

Typically, plants can be side dressed three weeks after they’re planted, when the plants are approximately six inches tall, when they form leaves, or when they begin to flower.

Look at the plant and see which category it could fall under. For instance, pumpkins enjoy being side dressed when they begin to form runners and again when flowering.

If you started them from seed, they probably won’t be six inches tall or be much of a plant three weeks after planting. Therefore, it wouldn’t be wise to fertilize pumpkins in this early state.

Potatoes benefit from side dressing when they begin to bloom. They also enjoy receiving fertilizer after they’ve been hilled a few times. This should be when the plant starts to gain a little height.

Therefore, it would be wise to check the height or the blooming cycle. Potatoes are typically too small to fertilize three weeks after planting.

There are a few plants which don’t need to be side dressed. Green beans and radishes are a couple of examples of plants which don’t benefit from this fertilizing technique.

However, most other plants will greatly appreciate your efforts and should thrive in your gardening area because of your efforts in caring for them.

It’s best to research specific plant varieties to know exactly when to side dress fertilizer. Yet, there may be times you’re working in your garden to side dress one crop.

As you look over, you see another plant variety. You might wonder if you could “kill two birds with one stone.” 

Use the general rules above to figure out if the plants are at a stage, in their growth, where they could be side dressed and it be beneficial to them. 

Hopefully, these general guidelines help you make wise choices in your garden while trying to save time. 

What You Should Not Do When Side Dressing Plants

When side dressing plants, there are a few things you must avoid to ensure their healthy growth and development. One of the key aspects to consider is timing. Avoid side dressing during a dry spell or when temperatures are low, as plants won’t be able to effectively absorb the fertilizer. During dry spells, the plant’s roots can’t absorb the fertilizer, which can damage the root system. In cold weather, plants grow slowly, and applying fertilizer won’t improve growth due to unfavorable growing conditions. In both cases, you’ll be wasting time and resources.

It’s also essential to carefully monitor the health and growth of your plants after side dressing. Here are a few practical tips to help prevent common errors and ensure your plants thrive:

1. Apply the right amount of fertilizer: Measure the appropriate amount of fertilizer for your plants based on their specific requirements. Over-fertilizing can lead to excessive foliage growth at the expense of fruit production, while under-fertilizing can lead to nutrient deficiencies. Always follow the recommended guidelines for the type of fertilizer you’re using and the plants you’re growing.
2. Avoid contact with plant foliage: When applying the fertilizer, be careful not to get it on the plant’s leaves, as this can cause damage, such as leaf burn. If you accidentally get fertilizer on the foliage, gently wash it off with water as soon as possible.
3. Water after side dressing: Properly water your plants after side dressing to help the nutrients penetrate the soil and reach the plant roots. This will also help prevent fertilizer from washing away and reduce the risk of nutrient runoff.
4. Monitor plant health and growth: Regularly check your plants for signs of nutrient deficiencies or imbalances after side dressing. Yellowing leaves, slow growth, or poor fruit production could indicate that your plants are not getting the right balance of nutrients. Adjust your side dressing practices accordingly to ensure your plants receive the necessary nutrients for optimal growth.
5. Keep records: Document the type and amount of fertilizer you used, the date of application, and any observations about plant health and growth. This will help you refine your side dressing practices over time and better understand the needs of your plants.

By following these practical tips, you can avoid common mistakes and ensure your plants receive the appropriate nutrients for healthy growth and abundant fruit production. Remember, successful side dressing requires careful planning, attention to detail, and ongoing monitoring of your plants’ health and growth.

Side dressing isn’t a complicated process. Once you understand where to apply the fertilizer, how to apply the fertilizer, tips for side dressing, and things to avoid, you’re ready to put this skill into motion.

Hopefully, your plants will thrive when they receive the nutrients they love in a way they like to receive them. It’s our hope that these tips will help you produce an abundant, and gorgeous, gardening area around your home.

Learn More About Side Dressing Plants

https://www.ag.ndsu.edu/crops/corn-articles/side-dressing-fertilizer-in-corn

https://ag.umass.edu/vegetable/fact-sheets/soil-basics-part-v-topdressing-sidedressing-nitrogen

https://www.riley.k-state.edu/docs/lawnandgardenandother/sidedressing.pdf