12 Perennials You Should Never Plant Next to Each Other

Perennial plants are a gardener’s best friend since they return year after year. While you may think perennials are mostly flowers, there are many perennial vegetables and herbs. Since they will stick around in the garden for a while, you must know which ones to keep apart. This is also true of annuals that don’t like growing with certain perennials.

Perennials You Should Never Plant Next to Each Other

Black-Eyed Susans and Daylilies

Black-Eyed Susans and Daylilies have different soil requirements. Black-Eyed Susans prefer well-drained soil, while Daylilies require moist soil. When these two plants are planted next to each other, they may compete for the same resources, resulting in one or both plants not thriving.

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Perennials You Should Never Plant Next to Each Other: Black-Eyed Susans

Black-Eyed Susans and Daylilies are susceptible to different diseases and pests. When planted together, these diseases and pests can spread easily between the two plants, causing both to become infected.

Daffodils and Hydrangeas

Daffodils prefer slightly acidic soil, with a pH range of around 6.0 to 6.5. In contrast, hydrangeas prefer more alkaline soil, with a pH range of around 6.5 to 7.5. When these two plants are planted next to each other, they will compete for the same nutrients and water, which results in stunted growth and poor health.

In addition to the nutrient competition, planting daffodils and hydrangeas together can also affect the color of the hydrangea blooms. The soil’s pH will determine the color of hydrangea blooms. Hydrangeas will produce blue blooms in acidic soil, while in alkaline soil, they will produce pink blooms. When planted nearby, daffodils can release chemicals into the soil that make it more acidic. This can cause the color of the hydrangea blooms to change from pink to blue or blue to pink.

Peonies and Lilies

Peonies need well-drained soil that is rich in organic matter. They also prefer full sun or partial shade. On the other hand, lilies require moist soil high in nitrogen. They prefer full sun to partial shade. If you plant peonies and lilies next to each other, they will compete for nutrients. This leads to stunted growth and poor flower production. The soil may also become too alkaline, which can affect the health of both plants.

Sunflowers and Pole Beans

When these two plants are planted next to each other, the sunflowers can outcompete the pole beans for resources. The sunflowers will take up a lot of space and nutrients, leaving the pole beans with less to grow and thrive. The pole beans may also struggle to climb the sunflower stalks, leading to stunted growth and a reduced yield.

Tomatoes and Fennel

Tomatoes and fennel are two popular vegetables that many gardeners like to grow due to their delicious taste and nutritional value. However, it is important to note that these two plants should never be planted next to each other. This is because fennel excretes a chemical called anethole, which can hurt the growth and flavor of tomatoes.

Anethole is a volatile compound that can be released into the air and absorbed by the tomato plant, causing it to grow poorly and potentially even die. Furthermore, fennel and tomatoes also attract similar pests and diseases, such as aphids and blight. When planted in close proximity, these pests and diseases can easily transmit from one plant to another, causing damage and reducing the overall yield of the crops.

Roses and Sage

Sage is a very aggressive plant that can quickly take over the garden if left unchecked. It can easily smother roses and other neighboring plants if planted too close to them. Sage also has a deep root system that can compete with roses for water and nutrients, making it even harder for roses to grow and thrive.

Finally, sage attracts a lot of insects and pests, including spider mites, whiteflies, and aphids. These pests can easily spread to neighboring plants, including roses, and cause serious damage. This is because many of these pests are attracted to the strong scent of sage, which can mask the scent of other plants and make them harder to find.

Garlic and Onions

Garlic and onions have different nutrient requirements. Garlic is a heavy feeder; it requires many nutrients to grow properly. Onions, on the other hand, are light feeders and don’t require as many nutrients. When they are planted together, the garlic may end up taking all of the nutrients, leaving the onions stunted and underdeveloped. Lastly, planting garlic and onions together can affect the flavor of both plants. Garlic has a strong and pungent flavor that can easily overpower the milder taste of onions. This can lead to a less desirable flavor profile in your dishes.

Strawberries and Cabbage

Cabbage is a heavy feeder that requires a lot of nutrients, while strawberries are light feeders. If you plant them next to each other, the cabbage will take up all the nutrients from the soil, leaving the strawberries with insufficient nutrients to grow properly. Lastly, strawberries and cabbage attract different pests.

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Slugs and snails commonly attack strawberries, while cabbage worms and aphids often attack cabbage. If you plant these two crops next to each other, you are creating a buffet for pests, which can quickly decimate your entire garden.

Asparagus and Alliums

Asparagus and alliums should not be planted next to each other because they are both heavy feeders and require a lot of nutrients from the soil. They will compete for the same nutrients when grown together, leading to stunted growth and poor yields. In addition to competing for nutrients, alliums also release a chemical called allelopathy, which can inhibit the growth of other plants. This can especially harm asparagus, which is already susceptible to disease.

Marigolds and Beans

Marigolds and Beans should not be planted next to each other because they have different soil requirements. Beans need much nitrogen to grow and produce healthy crops, while Marigolds prefer low-nitrogen soil. When planted together, Marigolds will take up most of the nitrogen from the soil, leaving the beans with insufficient nutrients to grow properly.

Furthermore, planting Marigolds and Beans together can also attract unwanted pests. Marigolds are known to attract spider mites, which can harm both plants. On the other hand, Beans are susceptible to aphids, which can also damage nearby Marigolds.

Mint and Strawberries

Mint is a highly invasive plant that can quickly take over your garden. It tends to spread through underground runners, making it difficult to control. Planting mint next to strawberries can cause the mint to choke out the strawberries, leaving you with a less productive crop. Secondly, mint and strawberries have different soil requirements. Mint prefers soil that is moist and rich in organic matter, while strawberries prefer well-drained, slightly acidic soil. Planting these two plants next to each other can cause soil imbalances, which can negatively affect the growth and development of both plants.

Rosemary and Cucumbers

Rosemary is known to attract pests such as the carrot fly, which can cause damage to cucumbers. In addition, rosemary has a strong scent that can repel pollinators necessary for the growth and development of cucumbers. Furthermore, rosemary and cucumbers have different soil requirements. Rosemary prefers soil that is well-drained, while cucumbers thrive in soil that is more moist.

Planting them together can result in either one or both plants not getting the soil conditions they need to grow properly. Another factor to consider is the competition for resources such as water and nutrients. When planted together, rosemary and cucumbers may compete for these resources, resulting in stunted growth or even the death of one or both plants.

Conclusion

It is crucial to research the characteristics of each plant before planting them together. This includes their spacing requirements, water and sunlight needs, and soil pH levels. By avoiding planting these 12 perennials together, gardeners can ensure their plants thrive and grow to their full potential. The goal is to create a vibrant and healthy garden that brings joy and beauty for years to come.