Are volunteer plants a bonus or a nuisance in the garden?

A few years ago, I overheard a conversation that my fellow master gardeners were having. The topic of discussion was volunteer plants. Well, I had never heard the term ‘volunteer plant’. Being intrigued, I did some research and began to observe volunteer plants around my garden. In this article, I will share some thoughts on whether volunteer plants are a bonus or a nuisance in the garden. In addition, how you can encourage or discourage volunteer plants.

Estimated reading time: 11 minutes

What is a volunteer plant?

In gardening, a volunteer is a plant that grows on its own without being deliberately planted. Volunteers can enter your garden in a few different ways. One way is from seeds dropped by a previous plant. A second way is from seeds transported by birds. Third, seeds blown in the wind. Fourth, seeds from homemade compost that has been added to garden beds. Now, let’s look at the definition of a weed by Merrian-Webster.com “a plant that is not valued where it is growing and is usually of vigorous growth”. So is a volunteer plant a bonus or a nusiance?

Many people I have spoken with believe that volunteer plants are some of the most vigorous plants in their garden. However, sometimes a volunteer plant is not appreciated where it is growing. Think about tomato plants popping up in the middle of cucumbers.

Therefore, depending upon where and when the volunteer plant appears, some may consider it a weed. It’s more of a nuisance than a bonus. However, there’s more to it. This article will explore the following topics:

• The pros and cons of volunteer plants
• How to decide whether to keep or pull a volunteer plant
• How to prevent or encourage volunteer plants
• Examples of volunteer vegetables, annuals, and perennials

Pros of volunteer plants in the garden

1. Free plants that germinate with no effort from you
2. Volunteer plants can be equally or more hardy than other plants
3. Volunteers can add a bit of fun and unpredictability to the garden
4. It can be exciting to find a volunteer plant

Cons of volunteer plants in the garden

1. Can come up in unexpected or unwanted places
2. You can never be sure what you’re getting. The plant may not produce fruit or flower depending upon whether the seed was an open pollinated or hybrid seed
3. Can ruin the crop rotation plan in a vegetable garden
4. They can carry soil borne disease

How to decide whether to keep or pull a volunteer plant

1. Location, location, location – Is the plant in the right location for its needs of sunlight, soil, and moisture conditions? Will it interfere with other plants growing in the same location? Does it work with your crop rotation plan in a vegetable garden?
2. Is the plant healthy? If there are signs of disease on the plant, it should be discarded.
3. Do you like the plant? If a volunteer vegetable comes up, consider whether you and your family enjoy eating that vegetable.
4. Do you already have an abundance of the plant?

How to prevent or encourage volunteer plants

To prevent volunteers, do the following:

• Deadhead plants before seeds form
• Apply a thick layer of mulch to the ground to prevent the germination of new seeds
• Be careful about what goes into your cold compost (e.g., compost where not enough heat is generated to kill seeds). Never throw plants that have gone to seed in the compost
• If a volunteer plant appears, pull it while it is still small
• In the case of potatoes, be sure to dig down and pull out all the tubers (potatoes) in the ground

To encourage volunteers, do the following:

• Allow your plants to go to seed by not deadheading
• Maintain good soil health in your garden

Vegetables and herbs

When I first heard about volunteer plants, it was all about vegetables. As I more closely observed my garden, I noticed many volunteer vegetable and herb plants. Five plants have produced most of my volunteers. Those plants are cilantro, chamomile, dill, tomatoes, and potatoes. These volunteers come mostly from the homemade compost I spread on my garden beds.

One thing to keep in mind with vegetables is to understand the difference between open pollinated and hybrid plants. Seeds from open pollinated plants will always produce a vegetable identical to its parent. Conversely, seeds from hybrid plants are not true to form. It’s more likely that the volunteer plant will resemble one of the plants that went into producing the hybrid seed. Also, some hybrid plants will not produce any fruit. With volunteers, you don’t know whether the plant is from an open-pollinated or hybrid seed.

Cilantro and German Chamomile

Homemade compost is interesting. In my case, the compost is made mostly of leaves, grass, and kitchen scraps. Therefore, it does not get ‘hot’ enough to kill seeds. I am careful with what I add to the compost, especially plants from the garden. I made the mistake, a few years ago, of throwing cilantro and German chamomile plants that had ‘gone to seed’ into the compost. Well, that resulted in several years of both cilantro and German chamomile all around the vegetable garden. The seed lived in the compost and as I spread compost onto my beds, the seed germinated. Thus, I had an abundance of both cilantro and German chamomile. It actually was a nusiance. The lesson learned is to be careful what you throw into your compost.

Dill

It’s so much fun to watch dill go through its various growth stages. Dill is a lovely herb that also has beautiful flowers and produces a large number of seeds. First, it starts with feathery leaves. Next, comes its umbrell of yellow flowers. Finally, the flowers turn to seeds. I find dill plants growing in some unusual places in and around the garden. I have found it behind our hydrangea bushes and in the middle of our cone flowers. Because dill seed is plentiful and lightweight, I believe it blows in the wind and lands in various spots. When I find a dill plant growing in an unusual place, I dig it up and transplant it into a more appropriate spot.

Tomatoes

Next, let’s talk about tomatoes. Within the confines of our vegetable garden there are always several volunteer tomato plants. I believe these come mostly from the compost. Some people feel volunteer tomato plants are the healthiest and best of their tomato plants. In my case, volunteer tomatoes usually appear where I don’t want them and thus get pulled when I first notice them. I should mention that I grow lots of tomato plants and usually do not have the space for the extra volunteer tomatoes.

Potatoes

Lastly, potatoes. Wow, what a surprise I had after the first year of growing potatoes. The next season, volunteer potato plants nearly filled the same bed from the previous year. Volunteer potato plants grow when potato tubers are left in the ground. Because I had such an abundance, I let them grow and they produced good potatoes. However, this creates a crop rotation challenge, and I now pull any volunteer potato plants growing in the same spot. I am a firm believer in crop rotation and thus do not plant the same crop in a bed for at least three years.

Annuals

An annual plant is one that completes its growing cycle within a year. Of course, depending upon your USDA garden zone, an annual in one zone can be a perennial in another. In my experience, annual plants do not produce as many volunteers as perennials or vegetables.

However, there are two annual plants I grow, which routinely produce a bounty of volunteers. First, there’s cosmos bipinnatus or garden cosmos. Over the years, I routinely grow cosmos for the gardens around our home. After two or three years of planting cosmos, I noticed volunteer cosmos plants showing up. In many cases, there was no rhyme or reason to where the plants appeared. Again, I assume the seeds were spread by either the wind or birds. In most cases, I leave the cosmos where they are because they’re healthy and didn’t seem to disturb surrounding plants.

The second plant the produces volunteers in my garden is calendula or pot marigolds. Calendula is an annual, however, it easily reseeds. My experience with calendula is that it mostly reseeds where it was originally planted as its seeds drop to the ground. Calendula can be vigorous in the number of plants that appear and thus may need to be managed.

Perennials

A perennial is a plant that lives for more than two years. From my experience, perennials produce the most volunteer plants. Many perennials spread by dropping their seed, by forming clumps that need to be divided, or by underground rhizomes (horizontal underground stems). For example, I have echinacea or coneflowers in my garden. During the growing season, I deadhead some of the blooms but leave others for the birds to enjoy during the winter. Each year, a new bunch of coneflowers appear as the seed drops to the ground.

I also have lupinus or lupine growing in my garden. Without fail, new lupine plants appear every year. Generally, new plants will appear very close to the parent plant.

One last example from my perennial garden. One year, a bleeding-heart plant or Lamprocapnos spectabilis mysteriously appeared in our garden. We were delighted at the beauty of the plant but could not figure out where it came from. One day, we noticed that our neighbor had a garden bed full of bleeding-heart plants behind their home. In this example, either the wind blew seed to our yard or a bird dropped the seed. In any case, we love our volunteer bleeding-heart plant.

To sum up perennials, many will produce new volunteer plants. Besides the ones I mention above, Shasta Daisy, Siberian Iris, Coreopsis, and Black-eyed Susan (Rudbeckia hirta) will also produce an abundance of volunteer plants. Therefore, when purchasing new perennials, speak to the experts at the garden center to understand a perennials growth pattern, Managing volunteers from perennials can take some unexpected work.

Now you have all the information you need to determine whether volunteer plants are a bonus or nuisance in the garden. Good luck!

Additional Information

Here is a list of posts that you may also find interesting to read.

• 6 easy steps to divide Siberian Iris
• Brilliant Method to create new garden beds: Lasagna Gardening
• Profusion Zinnias: An awesome flower to grow
• The Importance of Native Plants
• How to Create a Productive Small Vegetable Garden
• How to Create a Monarch Butterfly Garden
• Flowers in the vegetable garden, 7 that provide beneficial effects

References

• Horticultural Magazine
• The Farmers Lamp