Traditional horticulture dictated a method of fall cleaning of plantings to clean and prepare for spring. However, this approach can create more overhead for you and has several environmental disadvantages. Standing plants are a big part of rethinking how we can maintain a more sustainable landscape in the fall and throughout the year. Here are five reasons why you shouldn’t mow your garden in the fall and what to do instead.
Benefits of Not Cutting Back Plants in Fall
1. Seeding and Reproduction:
By letting preferred species self-sow and spread, you can easily obtain free plants that will cover the ground, suppress weeds, enhance soil moisture, prevent erosion, and improve soil quality, among other benefits. If you trim and tidy the flower heads in autumn, you will miss out on the opportunity to collect free seeds. Certainly, if you find that certain plants are overly aggressive, you may consider deadheading them. However, in some cases, it may be more convenient to simply remove and replace the plant altogether.
2. Providing Habitat for Wildlife:
In winter, the flower heads filled with seeds serve as bird food. When you have an abundance of plants with plenty of seed heads and seeds that fall to the ground, there’s no need to fill a bird feeder. By leaving plants standing until spring, birds are provided with cover from predators and shelter during winter storms. Additionally, other wildlife can benefit from the same protection.
3. Flood Control:
During the winter, the upright plant stems and grasses retain a considerable amount of moisture. If urban flooding is common in your neighborhood, keeping your plants in place can help prevent rainfall or snowmelt from draining away too quickly, as the plant material will retain the moisture. Shrubs and trees offer the same advantages. Having a higher amount of leaf and stem mass will result in reduced water flooding off impervious urban surfaces.
4. Natural Snow Fence:
Plants left standing also serve as a snow fence to minimize drifting across sidewalks, roads, and driveways, further adding to the benefits of reducing water runoff. Furthermore, this also aids in accumulating more snow around the plants, leading to insulation of the roots during extremely cold weather. Afterwards, the drifts will moisten the soil as the snow melts in the spring.
5. Enjoying Winter Interest:
The color brown is also worth mentioning, and during the dull days of winter, those stems and umbels can have a striking architectural quality. When thinking about winter landscaping, it’s important to consider how to incorporate pops of color like brown, black, copper, and umber. Take the time to appreciate the subtle beauty in the winter landscape and plan your design accordingly. After experiencing this, you’ll never have the desire to prune a perennial plant or ornamental grass again.
- Natural Fertilization: Allowing plants to decompose over the winter provides natural fertilization for the soil, enriching it with important nutrients for the following growing season.
- Protection from Temperature Changes: Leaving plants standing in the garden can help protect the soil from rapid temperature changes, which can preserve essential microorganisms and promote soil health.
- Reducing Work in the Spring: By leaving the garden untouched in the fall, you can reduce the amount of work needed in the spring, as many plants can provide a level of protection for new growth and also help to prevent soil erosion over the winter.
- Supporting Beneficial Insects: Many beneficial insects overwinter in plant stems and debris, so leaving the garden untouched can help support populations of these important creatures.
- Encouraging Natural Processes: Allowing the garden to go through its natural cycle in the fall can help maintain a balanced ecosystem and support the overall health of the environment.
When to Cut Back Your Garden
Are you wondering when the best time to cut your perennial and ornamental grasses is? Contrary to what you may see on social media, waiting for daytime temperatures to reach 50°F in the spring is not necessary. Research has indicated that the temperature of the soil is the crucial factor not the air is.
When the soil temperature is consistently 50°F or higher, the microbial activity in soil and plants is elevated, leading to increased activity in various creatures such as hibernating insects, spiders, and frogs as they emerge from hibernation and become active again.
In certain regions, the soil can become quite warm during the busy season, when fruit trees are in full blossom or when the lawn requires frequent mowing. The unpredictability of climate change and fluctuating weather conditions makes it challenging to establish the ideal time for spring garden mowing.
Using a soil thermometer is a cost-effective method to determine the optimal time to remove your plants from the ground. In addition, many states offer soil temperature data and maps to assist farmers in determining the optimal planting time. Check with your local land grant state university programs for this information. You can also find a map on the National Weather Service’s website.
How to Cut Back Plants
In spring, when it’s time to trim back your plants, you have options like using a string trimmer, hedge trimmer, pruning shears, or mulching mower, depending on the location and how densely the plants are clustered. However, it’s possible that in certain parts of your landscape, spring cleanup may not be necessary due to the flattening or breaking of plants caused by winter snow. Old stems and leaves can be left as natural mulch in your garden beds, saving you the cost of buying mulch.
Plants to Always Leave Standing
Some native perennial plants’ dry stems provide excellent nesting habitat for 25% of native bee species that nest in cavities. During spring and midsummer, I have observed that the following species are particularly active among various bee species:
- Coneflowers (Echinacea spp.)
- Golden Alexander (Zizia aurea)
- Ironweeds (Vernonia spp.)
- Milkweeds (Asclepias spp.)
- Rattlesnake master (Eryngium yuccifolium)
- Sweet Joe Pye weed (Eutrochium purpureum)
- Tall coreopsis (Coreopsis tripteris)
- Wild bergamot (Monarda fistulosa)
By allowing these plants to grow to a height of 12-18 inches in the spring, we ensure that native bees will have an ample amount of material to nest in. Some people may find this visually unappealing, but in a few weeks, new growth will have hidden them.
You don’t have to do a lot of work in a garden during autumn. Considering all of this, it might be best for both the garden and yourself to take a break. Afterward, you can appreciate the various ecosystem benefits it will offer in the coming months, including providing shelter and food for wildlife, and helping to minimize snow accumulation and urban flooding during frozen soil conditions.