Beneficial Insects

Gardening in a Growing Dome is rewarding. Upon entering the Growing Dome, we inflate our lungs with clean, fresh air, instantly melting away any fears or worries we had moments before. In this sanctuary we feed the fish, smell the blossoms, snack on some healthy treats along the way, and nourish the soil. Sowing seeds in the spring provides us with a vigorous summer crop for canning, dehydrating, freezing, and preserving the bounty, or even making friends with the neighbors. Planting in the fall renders tender leafy greens, crisp root crops, juicy cabbages, and other mouthwatering vegetables throughout the cool winter months. Spending several hours a day pruning, harvesting, watering, and simply caring for our crops, requires conscious and physical effort. There is no doubt that our labor is fruitful and sublime, but it is just that—labor.

A food forrest inside a growing dome greenhouse

Sometimes our hard work and intentions leave us defeated, overwhelmed, or even mistaken due to unforeseen outcomes. When this happens, we have a choice. We may either succumb to the reaction, or we may respond to the situation through investigation. Questioning will guide our investigation towards understanding how we arrived at the unforeseen outcome. Did I over-water or under-water? Is there enough ventilation? Is the soil missing an important mineral or nutrient? How long ago did I transplant? These questions, and many others, will guide us towards the answers we seek and need.

A yellowing wilted leaf

This journey allows us to learn and develop with our Growing Dome. A flourishing ecosystem does not develop overnight. The ecosystem we create within the Growing Dome has many interconnected parts that require our attention and efforts, especially when one particular part is constricting other parts. As facilitators of the Growing Dome ecosystem, our job is to maintain balance. Wilting or yellow leaves, insect infestations, powdery mildew, floating fish, and plant diseases are some of many indicators informing us that something is no longer in balance. These indicators tend to be our unforeseen outcomes. Let us dive in to investigate one of these indicators.

Pest insects are one of the most common challenges we face in the Growing Dome. Pest insects are a problem when their populations explode and we can no longer just bush them off of our food. We may treat these insects initially with home-made organic insecticides, but this will only provide temporary relief. We must look at the entire ecosystem and investigate what pieces are in excess and deficiency to restore balance. Ventilation, watering, and soil nutrition are three major sources of imbalance that should be tested. What is the relative humidity? How much air is being exchanged every hour? What does the moisture meter report at different depths and locations in the raised beds? What is the soil pH? How much NPK (nitrogen, phosphorus, and potassium) is present in the soil? What are the concentrations of secondary nutrients in the soil (such as calcium, magnesium, and sulfur)? How about micronutrients such as manganese, chloride, copper, boron, iron, zinc, and molybdenum? How important are some of these nutrients for the specific plant(s) that is/are being infested by pest insects? The answers to these questions will lead you directly to the source of imbalance.

“As facilitators of the Growing Dome ecosystem, our job is to maintain balance.”

While investigating the true source of imbalance, we must do something to curb the infestation so it does not spread to other plants. One solution is to make an organic insecticide from scratch, which has been discussed before in other posts, such as Why Aphids Suck and Homemade Organic Pest Control Sprays. Another, more appropriate solution is to plant habitats for, and introduce, beneficial insects. Creating habitats for beneficial insects is important before you release them. The habitat will encourage them to stick around, reproduce, and become part of the interconnected ecosystem. Yarrow, dill, alyssum, fennel, tansy, Queen Anne’s lace, cilantro (coriander), hairy vetch, marigold, lemon balm, mint, parsley, lavender, zinnia, caraway, cosmos, and goldenrod are all common plants that attract and provide habitat for beneficial insects. Some beneficial insects are more attracted to certain plants than others, so do a little research, and find out what you need to plant for an ideal habitat. It turns out that many of these plants have medicinal purposes for humans as well, so what are you waiting for? Some of these can and should be planted outside and around the Growing Dome too. Diverse ecosystems are healthy ecosystems. Now that we have habitats, let’s release some beneficial insects.

Growing Spaces gardener, Susan, shows us how to release different types of beneficial insects. She purchased the insects from Hydro-Gardens, a business located in Colorado Springs, CO. (Unfortunately Hydro-Gardens closed in May 2023. Per their website, Nature’s Control in Medford, OR is “now the manufacturer to their world famous Nematodes.”) Susan released beneficial soil nematodes, predatory mites, and parasitic wasps to help curb the pest infestation of spider mites, white flies, and thrips. Off camera, Susan tested the soil in each of the Growing Domes that were affected by the different pests. We learned that the soil was deficient in several important nutrients for proper plant development and growth. Once Susan identified which nutrients were deficient, she could then amend, top dress, and cultivate these nutrients into the soil. Susan responded to the problem through investigation, ultimately arriving at a long-term solution. The imbalance resided in the health of the soil, not the amount of water or air flow. This investigative process is not only enlightening and rewarding, but it is also inspiring. Enjoy the journey!

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Kyle joined the Growing Spaces team in 2015, and enjoys being involved in all the exciting projects and developments happening around here!I graduated from Pagosa Springs High School in 2009 and moved to Gunnison, Colorado to pursue a degree in Environmental Studies. After graduating from Western State Colorado University, I moved back to my home town Pagosa Springs. Since moving back home in 2013, I have been working to develop a farm in Arboles. In my spare time, one may find me backpacking in the wilderness, cruising on a mountain bike, slacklining in the park, or skiing Wolf Creek. I also enjoy creating art when I am not outdoors. The mediums that I enjoy working with are yarn, canvas and paint, and clay. I have been experimenting with aquapoinics and am always excited to share knowledge on the subject with others. I joined the Growing Spaces team in 2015, and enjoy being involved in all the exciting projects and developments happening around here!


    • Hello Anita,

      We used the rapitest kit to get a general overview of the macro-nutrient profiles in the soil. As far as amendments go, there is a lot to choose from. Earthworm castings, composted manures, composted plants, composted cover crops, mycorrhizal fungi, kelp meal concentrate, compost teas, fish emulsion, and biochar are all great things to add to the soil, depending on which nutrients you need to add. Some release slowly over time and others will be available immediately for a short period of time. It is usually a good idea to use a mixture of both. I sent you an email with more specific details on amendments.

      Thank you,


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