What Vegetables Should Not Be Planted Together?

Growing your own vegetables at home can be hugely rewarding. It’s a hobby that provides delicious crops for you to enjoy at your table, as well as the satisfaction of knowing that you’re sitting down to eat something that you successfully grew from a seed or baby plant. 

Part of this satisfaction is felt as a direct result of the amount of effort you need to put into growing your own vegetables. Unfortunately, it’s not as simple as just sowing a few seeds and hoping for the best. In the same way that certain wedding guests are best seated at separate tables, some vegetables are simply incompatible when it comes to sharing a bed.

What Vegetables Should Not Be Planted Together

Others can be incorporated into companion planting methods, but even with extensive trial and error, knowing which vegetables can be paired up and planted next to each other without causing problems can be a bit of a challenge. So, that’s what we’re here to help with. 

This article will take a look at some of the most popular pairings of vegetables to see what can be planted together and what should be kept at opposite ends of the vegetable garden

Can I Plant Carrots and Radishes Together?

Carrots and radishes share similar growing conditions which makes them an ideal match for companion planting. In case you don’t already know, companion planting is a method of growing that encourages two different plants to help each other during the growing period. 

This process can be beneficial for a number of reasons, including being a great way to save on bed space, repel the advances of certain bugs or insects, establish clear rows, and it can even reduce the number of weeds that try to crop up in your vegetable garden. 

It’s as easy as mixing the seeds for both vegetables together and sprinkling them into the furrows you’ve dug out of the soil for planting. Lightly cover with soil and water, then wait! Radishes germinate at a faster rate than carrots, so they can be harvested sooner to create space for the carrots to continue growing until they’re fully developed and ready to harvest.

What Can I Plant Next to Carrots?

As we’ve just discussed, radishes are one of the vegetables that thrive when you plant them close to your carrots, but there are plenty of others that, when planted next to carrots, can help you achieve healthy and hugely flavorful carrot crops as well as other produce. 

Some of the best choices of carrot companion plants include the following:

  • Legumes: Legumes are rich in nutrients and can transfer some of this to the soil they’re planted in via the process of nitrogen fixation. Planting legumes like pole beans or bush beans next to your carrot patch means they will share enriched soil.
  • Leeks: If your carrot patch has a pest problem, it’s worth planting some leeks nearby as these will do a great job of deterring carrot flies. It’s a companionship that doesn’t solely benefit your carrots, however, as leek moths are just as put off by carrots! 
  • Chives: It’s a well-known fact that adding herbs to your meal can improve the flavor, but the same thing can be said for your vegetable bed. Planting chives next to your carrots will help them achieve a better taste and texture, as well as deterring pests.
  • Nasturtiums: Another companion plant that’s great for keeping pests from picking at your produce is nasturtiums, which deter aphids, cucumber beetles, and bugs of various kinds. Plus, pollinators are attracted to them which carrots will benefit from.
  • Onions: If you just can’t seem to ward the carrot rust flies away from your crop of carrots, try planting onions in the same patch as a companion plant. Onions can eliminate your carrot rust fly problem as they will keep them away from your patch. 
  • Herbs: Some herbs, like sage and rosemary, can repel carrot rust flies like onions, whereas herbs like oregano, cilantro, and marigolds are good for getting rid of nematodes and cabbage moths, amongst various other types of pests.

These are just a few examples of vegetables that work well when grown closely with carrots, but there are plenty more that we don’t have room to mention. Why not try a few different ones and see which works best for you? 

What Happens if You Plant Vegetables Too Close Together?

It doesn’t matter how compatible two vegetable plants are for companion planting if you end up planting them too close together. All plants need to have enough space for their roots to stretch out and grow below ground, which they can’t do in an overcrowded bed.

Planting vegetables too close together can result in the following consequences:

Lack of Nutrients

Even the most expansive patch of soil has only so many nutrients like nitrogen to go around, and if you plant vegetables too close together in one area, they’ll drain these nutrients too quickly which can lead to sickly-looking vegetables and some that are abnormally shaped.

Pests and Disease

Overcrowded foliage makes it harder for the fresh air to circulate which can cause issues like powdery mildew and other fungal diseases to develop. Pest outbreaks can spread quickly from plant to plant if they’re close enough to touch, so leave some space between them. 

Too Much Moisture

When there are no more nutrients left in a drained, overcrowded vegetable patch, your only option is to water more frequently in the hopes of substituting a few. This can lead to moisture issues and a risk of disease, especially amongst veg with above-ground foliage.

A Battle for Sunlight

When the vegetable bed is overcrowded, there’s more chance that your plants will become leggy as they fight with each other to get enough light. There’s also the increased chance they will be undersized when it comes time to harvest the vegetables. 

What Should Not be Planted Near Garlic?

Garlic makes a great companion plant to a number of vegetables, particularly due to its pungent properties that keep away pests and bugs, and even rabbits if they get a chance. 

Vegetables that you can plant next to garlic with a good level of success include:

  • Beets
  • Kale
  • Spinach 
  • Carrots 
  • Tomatoes
  • Potatoes 
  • Eggplants
  • Peppers
  • Cabbage
  • Cauliflower
  • Broccoli 

However, there are a few trickier plants that actually suffer when planted too close too garlic.

  • Asparagus
  • Peas
  • Beans
  • Sage
  • Parsley
  • Strawberries

Planting garlic next to any of these vegetables can stunt their growth and cause your crop to be on the smaller side. This is because of the way that garlic affects the soil microbes. 

Can Peppers and Tomatoes be Planted Together?

You may come across advice in gardening books or magazines, or even from professional gardeners themselves, that tells you to avoid planting Nightshade or Solanaceae plant family members in the same plot. For example, peppers and tomatoes. 

While there’s some truth in the fact that this does increase the risk of disease developing and spreading, this isn’t the real reason behind this widely held opinion. 

The real trouble starts when you plant anything of these two families in the same bed directly after one another without rotating this patch with another type of vegetable plant, which we would never recommend doing due to the disease problems this can cause in the future. 

What you can do, however, is grow two plants from these families together at the same time. So yes, peppers and tomatoes can be planted together, and it’s actually a great idea if you’re limited with growing areas as you can keep them on a growing rotation to protect the soil. 

Another bonus to make growing these two vegetables together is that peppers and tomatoes share similar requirements regarding the conditions they can be grown in. 

Final Thoughts

As you have hopefully learned throughout this article, although there are plenty of plant pairings worth exploring the next time you want to try companion planting, there are some combinations that just aren’t a good match. 

Whilst we’ve provided you with some basic knowledge to get you started, there are hundreds of different combinations of plant pairings to try out. A lot of gardening is based on trial and error, so it’s worth making notes of your measurements each growing season to see if there are any patterns in what works best for certain vegetables and what doesn’t work at all.