Asparagus is a perennial and, therefore, it’ll have a home in your garden for many years. It will take nearly 3-4 years to grow spears that you can harvest from this plant. Since you’re investing all this time, space, and energy, you will want to make sure each season that you are surrounding it with neighbors that will allow it to thrive. Asparagus also has a lot of traits that can benefit the plants growing along side it. There are many things to consider with companion plants for asparagus. Here is everything you need to know to create harmony around this plant in your garden.
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Good Companion Plants for Asparagus
As mentioned in the introduction, Asparagus is a perennial plant that will be growing for many seasons in your garden. Choosing plants that can coexist and benefit your asparagus is key to ensuring optimal growth of this plant and its neighbors. There are some key traits of asparagus that good companion plants must coexist with.
First thing to note is that asparagus has a very deep root system. Therefore, a good neighbor for it should occupy a different level of the soil. If a nearby plant’s root system interferes with the roots of your asparagus, neither will grow and thrive as well.
The next thing to consider is the most common pest of asparagus, the asparagus beetle. Any companion plant that can keep this pesky insect away will be doing a great favor for your asparagus crop. Aphids and spider mites are also a danger you should look to control. What is great is that asparagus repels root-knot nematodes. Therefore, it has its own pest control to offer to its garden bed neighbors.
Finally, asparagus appreciates ground coverage around it. This helps the soil retain moisture and keep weeds at bay. While this can be accomplished with mulch, you can also find good companion plants that will do the job as well. This can be a better use of space in your garden.
Nightshades and Their Symbiotic Relationship with Asparagus
The nightshade family contains may great options for companion plants for asparagus. This is because they naturally repel asparagus beetles and are at risk from nematodes. As a result, they work in perfect harmony with asparagus. Nightshades help asparagus with its beetle problem and in turn asparagus helps keep nematodes away from the nightshades. It is a symbiotic relationship you should look to take advantage of when planning your garden around your asparagus.
Tomatoes
One of the biggest concerns when growing tomatoes is keeping pests away. By taking advantage of the mutual pest control benefits between tomatoes and asparagus, both crops will be better for it. In addition, tomatoes and asparagus wont interfere with each other’s root system.
Peppers
Pepper plants make a great garden bed mate for asparagus for the same reasons tomatoes do. Peppers coexist well in the soil with asparagus and both mutually benefit from the pest repelling affects of the other. Like most nightshades, pepper plants are great to plant with your asparagus.
Eggplant
Another nightshade crop, eggplant also repels asparagus beetles and can suffer from nematodes harassing its roots. Therefore, like tomatoes and peppers, eggplant makes an excellent companion for asparagus. The nightshade crops are the most tried and true options for companion plants for asparagus.
Petunias
Petunias are a nightshade flower that bring even more to the table than some of the vegetable crop options. They also have a symbiotic pest control relationship with asparagus, just like other nightshades. However, they do even more, as they are also a fantastic trap crop. Aphids and spider mites will prefer to munch on your petunias over your precious asparagus. Let’s not over look the wonderful splash of color they will also add to your garden. You can even simply plant them in pots and place them near your asparagus crop.
Shallow Root Plants Coexist Well With Asparagus
Asparagus has a very deep root system. Therefore, crops with shallow roots that occupy a different soil level can make great companion plants for asparagus. While it is nice that these crops don’t interfere with each other’s growth, asparagus can also benefit from the ground cover they provide. This ground cover keeps weeds at bay and shades the ground to help the soil retain moisture.
Lettuce
Lettuce varieties are excellent shallow root crops that can be planted along side asparagus. These leafy greens do an excellent job keeping weeds under control to help your asparagus thrive. Lettuce plants are also vulnerable to nematodes and will benefit from your asparagus repelling them.
Spinach
Spinach is another leafy green whose roots won’t grow too deep. Just like lettuce it will keep weeds at bay and is vulnerable to nematodes. You can even plant your spinach and lettuce together and they will have no issue growing while benefitting from the asparagus nearby.
Arugula
The third leafy green on this list is no different than the first two when it comes to pairing with asparagus. Arugula keeps weeds away, can be harassed by nematodes, and can be planted with your other leafy greens. You can have all the salad greens you need for your kitchen planted together right alongside your asparagus!
Radishes
Most root crops don’t grow great in close proximity to asparagus’s deep root system. However, radishes are the exception. They do not grow quite as deep as some other root crops and can coexist well with asparagus while providing ground coverage. Radishes even keep nematodes away just like asparagus and grow great near nightshade plants. This makes them a great option as a third wheel to your asparagus and nightshade pairing.
Aster Flowers as Companion Plants for Asparagus
Flowers from the aster family are well known for their pest control benefits and for attracting beneficial insects. These beautiful flowers will repel some of the annoying bugs that will harass your asparagus. Additionally, some act as a trap crop and attract harmful pests to them, keeping them away from your asparagus. To top it all off, pollinators and beneficial carnivorous insects will flock to your aster flowers, boosting their benefit to your garden even more. Like most plants in your garden, asparagus will love all of these benefits. Aster flowers make great companion plants for asparagus.
Nasturtiums
Nasturtiums are one of the best traps crop flowers. They will attract aphids and spider mites to them instead of your asparagus crop. By planting a short distance away, your asparagus will be less likely to be troubled by these pests.
Marigolds
Marigolds, like nasturtiums, are excellent at trapping aphids and spider mites. They also repel asparagus beetles to help keep your asparagus safe. Marigolds will help to repel tomato worms, which will benefit tomatoes if you have decided to pair that nightshade crop with your asparagus. Marigolds bring many benefits to your garden and asparagus appreciates them all.
Chrysanthemum
Our final aster flower worth mentioning is chrysanthemum. This pretty little flowering plant contains a natural insecticide called Pyrethrin. This chemical is deadly to many insects and will repel aphids, spider mites and asparagus beetles for your asparagus crop. They make an excellent companion along side your asparagus and will look wonderful in your garden.
Oregon State University Fact Sheet on Pyrethrin.
Aromatic Herbs
Most aromatic herbs bring a lot of benefits to your garden, while also tending to have shallow root systems. This makes them a perfect companion plants for asparagus. These herbs can give your crop pest control benefits, ground cover and attract beneficial insects. Not to mention, they will spice up your kitchen as well as your garden. Here are some of the best aromatic herbs to plant with your asparagus.
Dill
One of the best herbs to pair with asparagus is dill. This flowering herb repels aphids and spider mites to keep your asparagus safe. It will attract a lot of beneficial insects to control pests and pollinate your garden as well. Dill also benefits from the shade your tall asparagus will cast on its surroundings. As if that wasn’t enough, dill can act as a trap crop for tomato worms. So, if you choose tomatoes as another companion to your asparagus, dill will go perfectly with the two of them.
Cilantro
Cilantro offers many of the same benefits to your asparagus as dill does. It repels both aphids and spider mites and attracts beneficial insects. It also likes the shade asparagus offers. Yet another great neighbor for asparagus!
Comfrey
These tiny little bell shaped flowers attract a lot of pollinators to your garden, among other beneficial insects. Comfrey also grows very quickly and can act as ground cover to push out weeds from around your asparagus crop. This herbal flower will be right at home alongside your asparagus. Just make sure to prune this fast growing plant to keep its growth in check and you’ll have a happy garden.
Basil
Basil is another tasty aromatic herb that you can plant to help your asparagus thrive. It will repel asparagus beetles, one of the biggest pest concerns for it. Additionally, basil will attract aphids to itself and away from your asparagus. Beneficial insects will also flock to basil for shelter and to prey on the aphids that it attracts, which will keep them under control. Basil appreciates the shade it receives from asparagus, so the benefit to growing them together is mutual.
Borage
Borage is another sweet scented flowering herb that can boost your asparagus crop. This plant can act as a trap crop for aphids and beetles. It can also benefit tomatoes you may have partnered with your asparagus by repelling tomato worms. These little flowers will enhance your asparagus and your garden as a whole.
Lavender
Known for its sweet calming scent, lavender is a favorite flowering herb for many gardeners. However, bugs and pests, including spider mites, do not like this scent. Combine this with lavender’s shallow root system and you have an excellent garden mate for asparagus. Lavender is also a perennial and will aid your asparagus for the many years it will be growing.
Parsley
Parsley is a great aromatic culinary herb that makes for a good neighbor to asparagus. While it benefits from the shade asparagus provides, parsley will help to control pests as well. It deters troublesome asparagus beetles to keep your asparagus growing strong. This herb is a strong addition to your garden and your kitchen.
Sage
Another aromatic herb, that is both good for cooking and also produces wonderful flowers, is sage. Sage can help your asparagus by repelling asparagus beetles and acting as a trap plant for aphids. It also attracts many helpful insects like most aromatic herbs do. In addition, sage repels tomato worms and is a great choice if you have also chosen tomatoes to go along with your asparagus.
Mint
Mint is a popular trap crop that you can plant close to but still away from your asparagus. It will attract harmful insects such as flea beetles and aphids to it and away from your asparagus. If you’re a fan of mojitos this is the trap crop for you.
Strawberries Can Be Paired With Asparagus
Strawberries are known for their sweet taste and aggressive spreading. However, they are one of the good companion plants for asparagus because their aggressive spreading can be used as an advantage. Strawberries can be used as ground cover to control weeds and keep the soil moist for your asparagus. Meanwhile, your tall asparagus wont be bothered by the strawberries growing below it.
There is a catch though, if you plan to grow strawberries around your asparagus, plant your asparagus 6 inches (15 centimeters) deeper than you normally would. This leaves more space above the asparagus roots, so that the roots of both plants won’t interfere with each other.
Grapes and Asparagus Can Grow Together for Many Years
Asparagus and grapes can coexist with each other as long term partners in your garden. Grapes grow up a trellis, while asparagus occupies the ground. Both of them like the same type of soil. So, as long as the growth of the grape vines is kept in check, these two will get along just fine. And since they both will be occupying the space in your garden for a long time, there is little you will have to worry about beside pruning. While this companionship is less about benefits and more about coexisting, it can be a great option for those looking for a long term answer for a neighbor to asparagus.
Bad Companion Plants for Asparagus
Asparagus plants don’t clash with many garden plants and are pretty friendly neighbors, however there are some things to look out for. First, asparagus plants need a lot of nutrients from the soil to grow their spears every year. So, any plant that also needs a lot of nutrients will clash with asparagus and hinder its growth. Secondly, asparagus has a deep root system and other plants occupying that level of the soil will struggle to thrive with it and stunt the growth of your asparagus. Any plants that have these two traits make bad companion plants for asparagus.
Alliums Will Steal Soil Nutrients
Alliums make for terrible close neighbors to your asparagus crop. They will suck a lot of nutrients from the soil that asparagus needs to grow. It is best to keep some distance between these two crops so they don’t compete for resources in the soil.
Deep Rooted Plants Will Interfere With Each Other
Plants with deep roots like asparagus aren’t good to plant close to each other. You don’t want your crops interfering and competing with each other in the same space under the soil. Root crops, such as carrots, parsnips and beets all grow better away from your asparagus.
Another deep rooted crop that you want to avoid pairing with your asparagus is potatoes. While most nightshade crops pair well with asparagus, potatoes do not. The harm the two cause each other competing for soil space out weighs the benefits that they can give each other with pest control. You’re better off choosing a different member of its family to room in your garden with your asparagus.
The last two notable deep root crops to avoid planting to close to asparagus are pumpkins and rhubarb. Both will compete with asparagus if planted too closely. However, both can actually fair well if planted a little further away where they aren’t at risk of clashing under the soil. The leaves from the rhubarb you harvest can be used as mulch for asparagus. While pumpkins can grow out and cover the ground beneath asparagus to help control weeds. These two are only bad if planted too closely.
