Written by: Penelope Hyland, Pueblo County Extension Master Gardener

Fall is finally here!  Most of us have spent this past hot summer fighting all kinds of insects that have been eating both our edibles and ornamentals – especially the grasshoppers!  Now it is time to thoughtfully put both our edible gardens and our landscapes to bed for the winter.  In doing so, we need to especially think about how our landscapes help insects survive through the winter.  After you have just spent the summer dealing with pests, why would you want to consider helping them to survive the winter?

So, just why is it that bugs are so important?  Insects are the basis of the ecosystems that support human life!  The variety of life depends upon the millions of insects that make up the base of the food chain and allow the ecosystem to function.  Insects are the key component of every terrestrial food ecosystem.  Their main role is to eat and be eaten.  It is difficult to imagine the importance of these tiny creatures that we don’t even see for the most part and then only to attempt to eliminate, but they play a crucial role in ecosystems.  As the most valuable member of the ecosystems that support human life, insects:

• Keep the ecosystem in balance
• Condition the soil; insects turn more soil than earthworms
• Provide nutrients for the soil; insects redistribute nutrients in the root zone
• Maintain water quality
• Are instrumental in decomposing organic manner; insects decompose over 90% of plant, human and animal waste
• Remove waste from the environment which lessons the spread of disease
• Assist in pollination and seed dispersal; enable plants to produce fruits and seeds
• Are a key source of medications
• Help purify air
• Absorb chemicals
• Stabilize climate
• Recycle nutrients
• Form and protect soil
• Provide a food source for birds, reptiles, fish and amphibians
• Are instrumental in producing honey, beeswax and silk
• Help to keep harmful pests in check; only 1% of insects are pests

Insects are the biological foundation for all terrestrial ecosystems.  They cycle nutrients, pollinate plants, disperse seeds, maintain soil structure and fertility, control populations of other organisms and provide a major food source for other taxa.  Plants and insects have a close symbiotic relationship in which the majority of plants can’t reproduce without insect intermediaries.

In spite of their vast numbers (the biomass of invertebrates dominate the animal world), more than 40% of insect species are declining and 1/3 are endangered.  The extinction rate is 8 times faster than mammals, birds and reptiles.  The total mass of insects is decreasing by 2.5% each year.  Flying insects have decreased by 76% and more than 40% of the world’s insect species could be extinct in the next three decades.  Insects are the most varied and abundant species and are essential for the proper functioning of ecosystems.  They are a vital influence on agriculture, human health, and natural resources.  The decline of insect numbers will have a devastating effect on ecosystems which are vital for human existence.

Insects are considered a keystone species that provide invaluable ecosystem services beyond pollination and provide a helpful control of pests.  Unfortunately, a small percentage of insects are actual pests that destroy edible crops and upset the balance of healthy ecosystems.  For the most part, if left alone, beneficial insects will eat the pest insects.  Most of us are taught that most insects are pests, when, in fact, only a very small percentage of insects are pests that need to be controlled. 

Since insects are so valuable to healthy ecosystems, it would be beneficial to assist them in overwintering, especially as insects rely on external sources for heat.  There are some very simple things we can all do to help facilitate this:

• Delay the majority of your landscape cleanup until spring
• Leave dead stalks and grasses as homes for insects to overwinter
• Leave some leaves on turf and around plants
• Leave dried stems until spring
• Leave dead seed heads until spring

It is also very beneficial for your lawn to leave leaves instead of raking and bagging.  Leaves are a valuable source of nutrition even in a dry state.  For the leaves that have fallen on your turf, simply mow them into the lawn as a natural fertilizer.  Leaves that are in your flower beds and around shrubs and trees can be gathered around the base of those plants for extra protection from the cold temperatures throughout the winter.  In the spring, they can be turned into the soil around those plants to provide organic matter.  The use of leaves then provides protection and fertilization for your plants, but also provides a winter home for beneficial insects.

It is also helpful to note that leaf blowers can kill over 10,000 insects in a single use.  Please consider finding other ways to gather leaves instead of using a blower.

Leaving a slightly bedraggled landscape over the winter is a difficult concept for a lot of people.  However, it is not a new concept.  Our ancestors knew the value of delaying a total cleanup until spring which also encouraged additional plant growth.  Many artists have seen the different look of the beauty of dried stems covered with snow.  The main benefit is the knowledge that you are doing your part to help maintain healthy ecosystems!