As summer winds down, you may not be diligently watering parts of the garden every day like you were in the longest, hottest days of July, but there’s still plenty of work to do. Investing time into important tasks now can make life easier for you (and your plants) in spring.
There are also plenty of potential mistakes to make in the fall garden, many of them concerning timing. When it comes to dividing perennials, planting bulbs, and more, timing is key. You don’t want to push things off until the ground is frozen and it’s too late.
Additionally, a lot of autumnal tasks are about protecting your soil and protecting native wildlife throughout the coldest months of the year. It would be a mistake not to think about your soil ecology and how it fits into the broader picture.
There’s a lot to think about, especially when you’re planning short-term tasks that will affect the garden’s long-term future. Worried that you might miss something? Scared that you might make the wrong move? We’ve rounded up a list of fall gardening mistakes to avoid this year.
Ignoring Weeds
Remove them now so they won’t be there in spring.
Prime time growing season may be coming to an end for your vegetable garden and flowers, but the same can’t be said for weeds. Ignoring weeds at this time of year, especially as your other garden chores begin to dwindle, is a crucial mistake.
Now is an ideal time to remove perennial weeds. These weeds are probably slowing down their above-ground growth while moving energy towards their roots in anticipation of winter. Remove them now, so they won’t be there in spring. As for annual weeds, you’ll want to remove them before they re-seed.
Any weeds near your perennials, including shrubs, small trees, and perennial flowers, will continue to compete for precious resources during winter, which will be even more limited. Other weeds that don’t seem as detrimental can still spread and make life difficult for your intentionally cultivated plants as you approach the first frosts.
Now is actually a really easy time to remove weeds. They tend to be simple to see in the fall landscape as the grass fades in color. They also won’t regrow as quickly since the days are getting shorter.
It may be tempting to give up on weeds in autumn, especially on chilly, dreary days. If you continue to weed until the first frost, your future self will thank you in spring. Put on a light jacket, grab your favorite gardening gloves, and get to work with those pesky weeds.
Cutting Down Perennials
The above-ground foliage, even once it gets crunchy and brown in winter, forms a protective layer.
It is a common fall garden mistake to cut back all of your herbaceous perennial plants. If you have a lot of perennial flowers, you may be thinking about cutting them all down to the soil level for a clean and organized look. Perennials will probably bounce back in the spring if you do this, but it’s somewhat detrimental to both the plants and local wildlife.
The above-ground foliage, even once it gets crunchy and brown in winter, forms a protective layer around the crown of the plant. This helps shield perennials from some of winter’s harshest conditions, trapping snow and providing insulation. The dead foliage also helps protect the new shoots that pop up in early spring.
This additional winter protection is especially the case for any perennials you’re trying to keep alive even though you’re on the colder edge of their hardiness range.
If there are any perennials that have been struggling with disease or pests, they’ll need extra protection too. Cutting them down to the base might be too much to come back from, depending on the severity of the issue.
If you cut down perennials, you’ll also be doing a disservice to wildlife. Local birds depend on seed heads for food throughout winter when food is otherwise scarce. Beneficial insects, including pollinators, also call your crunchy perennial foliage home throughout the chilly months.
Sometimes, in autumn, there are perennials you decide not to grow next season, but avoid removing them at this time. You may not care about the plant itself, but leave it for the wildlife until spring.
Leaving Debris Around
If you’re planning to rotate crops, don’t leave the fruits lying around.
While it’s important to leave the above-ground foliage of your plants alone, both for the health of the plants through winter and to benefit local wildlife, you still don’t want to leave excessive debris and supplies all over the place.
Don’t use the importance of protecting perennials and wildlife as an excuse to abandon your duties entirely. For example, you should leave perennials alone, but you should definitely pull weeds. It’s all about finding the right balance for your garden.
Similarly, leaving your annual vegetables alone in the garden can be a good idea, as they’ll enrich the soil. However, if you’re planning to rotate crops, don’t leave the fruits lying around.
You may be totally over your cherry tomatoes at this point, but if you leave a bunch to decay on the vines (and then the ground), you can bet you’ll get volunteers next year. This can be a problem if you’re trying to rotate crops or having disease issues.
Now is also the right time to remove temporary fencing, row covers, metal garden staples, trellises, etc. Leaving them outdoors through fall and winter can be damaging and can make them difficult to retrieve in spring.
Skipping the Last Harvests
Gather and dry your herbs before it gets too cold so you can use them all year.
Remember spending late winter and early spring pining for the last frost so that you can finally start moving your vegetable seedlings outdoors and direct sowing seed? Remember how excited you were to harvest the first cucumbers and peppers?
By fall, a lot of the excitement has worn off. You’ve made countless caprese salads, you’ve pickled your heart out, and maybe you even canned your tomatoes. You may be struggling to gather the enthusiasm to harvest yet another zucchini.
These last harvests may seem boring and repetitive right now, but you’ll regret it if you leave these final fruits and veggies behind. Give it a month or two in winter, and you’ll be missing your summer garden and all its splendor.
Cherish these last harvests. Discover new ways to process and eat everything that’s left. Gather and dry your herbs before it gets too cold, so you can use them all year. Make yet another bouquet of zinnias, and treasure it.
Of course, harvesting the last fruits and veggies on the vines of your summer edibles has another benefit: Making room for a fresh batch of fall crops. New veggies will inspire you to keep gardening well into winter.
Waiting Too Late for Fall Crops
The timing varies from crop to crop, but generally there are a few steps you should take to plan properly.
You may be surprised by the number of cool-weather crops you can still start from seed in the fall, even if you’re located in a cooler zone with the first frost fast approaching. Many fall crops have a short growing window and plenty of them are frost-tolerant; some even grow better in cool weather.
However, it’s critical that you get the timing right, especially in colder areas. Late planting is another very common fall garden mistake. The timing varies from crop to crop, but generally, there are a few steps you should take to plan properly.
First, determine if your intended fall crop is frost- and/or freeze-tolerant. For example, broccoli is definitely frost-tolerant and will even survive a few freezes, but once the temperatures get below 24 degrees or so, broccoli is a goner. Determine when these temperatures are most likely to hit your region.
Second, figure out the days to maturity for what you intend to grow. If broccoli needs two or three months to grow, subtract that amount of time from the freezing time period you determined in the prior step. This will tell you when to start seeds. It may be earlier than you realize.
Do the math in late summer or early fall and mark your calendar in advance, so your fall crops will have plenty of time to grow for optimal harvests.
Leaving Young Trees Unprotected
Adding mulch around young trees can protect them from the cold, further insulating their roots.
Fall and winter can be a challenging time period for young trees, especially trees that you just planted in the past year. You probably put a lot of time, effort, and money into these trees, so it is worth it to take a few steps in the autumn to help them survive the upcoming chilly months.
Adding mulch around young trees can protect them from the cold, further insulating their roots. This is especially important if you’re just narrowly within the hardiness window for a tree. Until they are more established, they may have a difficult time with the cold.
You can also cover young trees with burlap during particularly cold times. Get the burlap now and have it ready in case of unexpected temperatures that go below your area’s average.
If you have a problem with deer in your area—and you’ll know if you do—then you should take steps to protect trees from them. Deer may rub their antlers on the bark of trees in fall. For a small tree, this damage can be a major setback or even be deadly.
To protect small trees from deer, you can put up a physical barrier around the trees, such as chicken wire. If you haven’t had deer issues before, this is probably not necessary. But if deer negatively impacted your garden all summer, then they may continue to wreak havoc in the fall.
Wasting Your Leaves
This is some of the best organic matter for your garden.
If you’re fortunate enough to have plenty of leaves around, then you have potential top-notch compost. Large piles of leaves will turn to compost with time, otherwise known as leaf mold. You can use leaf mold interchangeably with compost in the coming seasons.
However, you don’t have to wait for leaf mold to form, either. You can start piling up your excess leaves on top of your empty raised beds or around perennials as mulch. The leaf mulch will break down over time, adding nutrients to the soil.
Covering empty raised beds and gardens with leaves is a fast, easy, and free way to protect your soil from erosion, minimize weeds, and add nutrients. Encouraging good soil ecology all winter will have you ahead of schedule when it’s time to start preparing for spring planting.
Some gardeners like to leave their leaves where they fall to help local insects, and this practice is totally fine. Insects do use fallen leaves for their habitat. However, insects will still find your leaves if you’ve moved them off the grass and are using them as mulch or compost.
Additionally, leaving all your fall leaves on the grass can cause bare spots, which weeds will colonize. Some of us gardeners are pickier than others about weeds in grass, so this may be of importance to you.
Letting Flowers Go To Seed
There are plenty of flowering plants that you should not let go to seed, so it’s key that you distinguish between the two.
Letting most native flowers go to seed is definitely a good thing. These seeds provide food for birds during the coldest time of year, when food is otherwise limited, and spent flowers and seed heads also provide habitat for beneficial insects.
That said, it’s easy to use this as an excuse to totally ignore all your flowers and just remove fall flower maintenance from your list of chores. There are plenty of flowering plants that you should not let go to seed, so it’s key that you distinguish between the two in autumn.
If there are already some somewhat invasive plants in your garden that you spend time dividing and controlling each year, you definitely don’t want to just let them self-seed willy-nilly. Remove the seeds and compost them or throw them away.
You may also want to think about non-native species, whether they are aggressive spreaders or not. Of course, it’s okay to have some non-natives in your garden, but think about how they may affect the local ecosystem if left unchecked.
Finally, if there are any parts of your garden that you like to keep neat and tidy, you may want to remove seed heads in and around this area, to save you the time weeding next fall. You can make it up to the local wildlife by sprinkling a native pollinator seed mix elsewhere.
Dividing At the Wrong Time
You want to divide at a time when the plant is still actively growing foliage.
Autumn is often the perfect time to divide and transplant spring- and summer-blooming perennials. This way, you’ll get to see their beautiful warm-weather flowers before division, and then they’ll have all winter to establish again before next year’s display.
However, if you divide too late into fall, the transplant might not go well. You want to divide at a time when the plant is still actively growing foliage, often at least six weeks before the ground freezes over.
This ensures that the plant still has enough energy to start establishing roots before the ground is solid. Once the ground freezes, it be physically difficult for roots to grow and they will struggle to access any water.
Determine the last frost date in your area and count about six weeks back. Consider this your rough deadline for dividing perennials. If you’re more like a month away from the first frost, you could still give division a shot, but the plant could exhibit stunted growth.
If you’ve missed this time frame, don’t worry too much. You can always divide in the spring once the ground thaws. Dividing summer-blooming perennials in spring still gives them plenty of time to settle before flowering again.
Skipping Mulch
It helps the soil retain moisture and discourages weeds from taking over.
There are many benefits to mulching your garden in the fall, whether you mulch around existing plants or completely cover empty beds. While you may have your mind on the plants in spring and summer, now is the time to mulch to protect the ground.
Mulching protects soil from erosion throughout the winter months. It helps the soil retain moisture and discourages weeds from taking over. The “life” of your soil is just as important as the plants that grow in it, so you want to protect it.
Mulch also adds a physical layer of protection from the cold, insulating not only perennials’ roots but also the worms, fungi, and other forms of life within the soil. Keeping all these organisms alive and happy is the foundation of healthy soil ecology.
Best of all, many of us already have free autumn mulch available to us: fallen leaves. You can gather all your leaves in a pile and apply them as mulch right away. You can also gather leaves in large compost piles, and use them as both compost and mulch as they begin to decay.
Forgetting About Bulbs
Research the best planting time for your favorite blooming bulbs in your area and plan accordingly.
Lastly, if you have your heart set on spring-blooming bulbs, don’t forget to plant them now in the fall. It’s easy to lose track of when bulbs should be planted, especially since your autumnal efforts won’t be rewarded until spring.
Daffodils, hyacinths, tulips, and more are the harbingers of spring. We often see them in all their glory and think “this year, I’m going to plant some of those.” By the time fall rolls around, daffodils are often the last thing on our mind, and then we miss the ideal time window.
This is especially the case with bulbs that bloom in really early spring, but many summer-blooming bulbs, such as irises, perform best when you plant them in fall, too. If you manage to get bulbs in the ground now, you’ll be patting yourself on the back in a few months.
Research the best planting time for your favorite blooming bulbs within your area and plan accordingly. A lot of them involve a little bit of foresight and planning. Many online retailers will ship bulbs to your region at the time that is most appropriate.
Get your bulbs in the ground before it freezes—about one or two months beforehand, if possible.
