One of the biggest mistakes many gardeners make in the fall is fertilizing their perennials – when, as it turns out – it’s actually the one time you should always avoid doing so at all costs!
As autumn settles in, many gardeners find themselves tackling a long list of chores in their garden and flowerbeds. Whether it’s pulling up vegetable plants and annual flowers, mulching flowerbeds, or cutting back perennials, one thing is for sure, there is plenty to do!
However, one common practice you can confidently skip this season is giving your perennial plants a dose of power before the winter chill sets in. Not only is it unnecessary, it can also be detrimental to their long-term health. In fact, in some cases, fall fertilization can lead to perennials struggling to even survive the winter months.
Why To Avoid Fertilizing Perennial Plants In The Fall
Perennials In The Fall
During the fall, as temperatures drop and daylight hours shorten, the growth of perennial plants slow significantly. This period marks a natural transition for the plants as they begin to prepare for the challenges of winter.
In the fall, bloom cycles are very rare. In fact, except for mums, asters and sedum, most perennials haven’t just stopped blooming, they also halt their production of new branches, stems, and foliage.
While it may seem as though your perennials are shutting down completely, they are actually using the time to prepare for the long, dark and often very cold winter ahead.
Instead of growing, their focus shifts to strengthening root systems and storing energy. This is not only important for them to be able to survive winter, but even more, it’s essential for the plants to have the energy to emerge in the spring and be ready to bloom big.
How Fertilizing Harms Perennials In The Fall – Why To Avoid Fertilizing Perennial Plants In The Fall
So what does fertilizing in the fall do to perennials? And, more importantly, how does it harm them?
When perennials are given fertilizer late in the season, it can trick them into a growth cycle. In place of preparing to go dormant, they instead gear back up as though it’s spring. Instead of feeding and storing energy to their roots, they actually begin to gear back up for foliage and flower production.
This gear up couldn’t come at a worse time for perennials in the fall. Any new growth that occurs simply doesn’t have time to mature. And because of that, it is highly susceptible to damage.
In addition, with far less power in their roots, the plants are also in high danger of falling victim to all of the freezing and thawing that can occur through the winter. And even if they do survive, they have far less power in the spring to produce leaves, buds and blooms.
So when should you stop fertilizing perennials? To give them maximum time to slow down and naturally head into dormancy, you should avoid fertilizing perennial plants eight to ten weeks before your first expected frost. For most climates, mid-August is a good rule of thumb to discontinue fertilizing.
What You Can Do For Late Season Perennials – Why To Avoid Fertilizing Perennial Plants In The Fall
So now that we know fertilizing is out in the fall, what can you do in the fall to help your perennial plants thrive during the winter? Here are a few key chores to perform to help your plants survive winter – and come out strong next spring!
Cutting Back Perennials
One of the most important fall tasks for most perennials is to cut back any decaying foliage. This not only tidies up your garden but also minimizes the risk of pests and diseases overwintering in the decaying foliage.
Once you have cut back your perennials, fall is also a great time for dividing favorite perennials such as hostas, daylilies, coneflower and more. Dividing plants every three to five years can keep roots from becoming root bound. It also keeps plant size manageable in bed spaces. See: 5 Great Perennials To Divide In The Fall – Get More Plants For Free This Fall!
Mulching – Why To Avoid Fertilizing Perennial Plants In The Fall
Once you have cut back your plants and divided any overgrown perennials, it’s time to mulch Mulch acts as an insulator, helping to regulate soil temperature and protect roots from freezing. Even more, it also helps keep competing weed seeds from finding a home next spring to sprout.
While traditional fertilizers are not recommended, you can provide a small amount of compost around your plants before mulching. The nutrients in compost break down slowly, ensuring that they won’t encourage new growth right before winter but will be available as your plants come back to life in the spring. An inch or so of compost is ideal. Affiliate Product Link: R&M Organics Premium Organic Compost
Once your compost is down, you can put your regular mulch on top. How much mulch is enough? Ideally, you want a four to six inch layer of mulch around plants.
This layer is enough to help keep the soil temperature more moderate over the winter months. Plants suffer more from the soil constantly thawing and freezing. But mulch keeps this to a minimum – and the roots of plants safe.
Don’t Forget To Water!
Autumn can often be dry, but it’s important that your perennials still receive adequate moisture, especially before the ground freezes. Well-hydrated plants are better equipped to withstand the winter.
Here’s to making sure you avoid fertilizing your perennial plants this fall – and to helping them properly get ready for winter – and a great growing season next year!
Simple Garden Life
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