It’s time to put the garden to bed for another season
Summer is done for another year and we are well into autumn. It’s great to enjoy all things pumpkin and the glorious colour of the fall leaves but before you can say Jack Frost it will be nipping at the garden. To clean or not to clean… that is the question. Cutting back and cleaning in the fall is ultimately a matter of choice.
There are generally two extremes when it comes to winterizing the garden, those who love a thorough clean-up in the fall and those who prefer to wait until spring to get everything tidy. My personal opinion is the sweet spot is somewhere in the middle. Doing a bit of work in the fall can set you up for success in the spring and there are a few tasks that I would always recommend you find time for but on the “other side of the coin” leaving some of your perennials in their various stages of dieback can be good for wildlife and just darn pretty in the garden. Some plants look amazing through the winter season, dried hydrangea flowers, grasses, seed heads, and berries (also food for birds). If you’ve ever seen the sunlight streaming through a clump of frost covered tall grass, then you would never consider pruning your grasses in the fall again. It sparkles and shines better than any diamond.
That being said there are a few plants that benefit from a bit of attention at this time of year and a few tasks that really do need to be done.
I would recommend you cut back is your iris, especially if you live in areas where iris borer can be problematic. Iris borer (Macronoctua onusta) is a small caterpillar that lives in and eats your iris bulbs. It likes to lay its eggs on the leaves and overwinter, so if you cut off the leaves then they have no place to go and you are less likely to have them infest.
Another clean-up job that I would not recommend you skip. This is because of a disease called black spot. Caused by a fungus, it doesn’t kill your roses but instead causes the leaves to yellow and are covered in, you guess it, black spots. Because it’s caused by a fungus leaving the old leaves on the ground around your plant can supply the needed inoculation for the new emerging leaves in the spring. If you clean up and get rid of the old leaves (don’t add them to the compost, that is just moving the problem) you will be minimizing the overwintering fungus and hopefully have less black spot next year.
Good garden hygiene when growing veggies will pay off in the long run. If you have had issues with diseases such as rusts or blights then you need to do a bit of work in the fall and clear away any diseased plant material. Make sure you are rotating your crops and just as with the roses you don’t add any diseased plant material to your compost you need to get rid of them. Many diseases of veggies build up inoculant in the soil, so need to do what you can to reduce that.
Another great thing to consider if you are not growing fall/winter crops in your veggie patch is to plant a cover crop. Cover crops, or green manure as they are also called, are plants that you seed and grow through the winter with the intention of tilling (or incorporating) into the soil in the spring. You do this to build up nutrients and organic matter into your soil. If your cover crop includes legumes you will also benefit from their fixing of atmospheric nitrogen (pretty much it’s free nitrogen fertilizer). This winter growth also acts to cover the soil and prevent erosion that can occur with bare soil. Cover crops are crops you grow to feed the soil which will in turn feed your plants next season. If you think a cover crop is for you head down to GardenWorks and check out some of the different mixes available, but do it soon… you should be sowing that cover crop right now.
Most herbaceous perennials (plants that die back over the winter but come back every spring) benefit from dividing and this is best done during the times they are not actively growing, so either in spring or fall. The choice is yours, personally I divide mind in the spring because that is usually when I am thinking about the layout and design of my spaces, that way I can divide and replant to exactly where I want them. But the choice is yours. The exception is spring flowing perennials, I would recommend that you divide them in the summer after they have finished flowering, not in the fall.
Waiting until after flowering to tackle spring flowering plants is just a good guideline overall and it also applies to pruning of spring flowering shrubs. Plants that have adapted to flowering early will set their flower buds the summer and fall before and will actually go through the winter with the flowers ready to go. If you prune spring flowering shrubs in the fall you may be cutting off next spring’s flowers. Fall/winter pruning of other (non-spring flowering) deciduous shrubs can be helpful since without the leaves you can really see the branch structure. But… guess what? It’s also good to wait until the spring to see if you’ve had any winter branch die off. So once again it’s a matter of choice. I would not recommend pruning of evergreens during the fall or winter, early spring and summer is best for the evergreens.
I’ll bet you thought you were going to get out of weeding for a while but guess what, weeds can overwinter and some in milder climates like on the coast they can continue to grow through the winter. Also, as many of the plants in your garden die back and go dormant it’s much easy to see where the weeds are getting bad and where you may need to concentrate your efforts to make sure they don’t go to seed or spread. So, take some time this fall to get rid of few weeds, you will be grateful in spring that you did.
What’s one of the best ways to keep weeds from getting out of control? You guessed it… mulch. I know what you are thinking “you keep telling us to use mulch to retain water in the soil, so why do we need to mulch in the winter… there is no lack of moisture in the winter” but it is still a perfect time to check your mulch and add a bit more if necessary. There are many benefits from mulch other than water retention, such as weed suppression and it acts as a protective layer for your soil (think of it like a blanket). This is especially great for those of us who live in areas that don’t get consistent snow coverage. Snow is a great insulator on the soil but without it our soils are exposed to erosion and the extremes of temperature fluctuations. I personally love to use fall leaves, which incidentally you should be raking off the lawn (grass does not appreciate a leaf mulch, unless it has been cut into small pieces by your mower). Just take a little care if you are using leaves to mulch your trees, you are going to want to use a plastic collar to prevent mice from girdling your trees. Mice can hang out and hide in leaves and will sometimes nibble away at the bark (if they nibble all the way around it is called girdling and can kill the tree, hence the plastic collars). Mice are not attracted by leaves as someone recently tried to convince me, they are more likely attracted to that BBQ that you still haven’t cleaned from the last summer cookout, but they will take advantage of a place to hide. Don’t ever let this prevent you from using leaves as a mulch, mice will find a place to hide even if you do take all your leaves away.
One thing to keep in mind is the natural process of plants is to have the rotting plant material stay in place (if your aesthetic senses can handle it). In nature no-one comes along to clean up the leaves and cut away the old leaves, they stay in place and compost down over the winter to release their nutrients back into the soil for the plants to use in the spring. It’s for this reason that I always leave the leaves on the garden.
Other than mulching with leaves I leave the soil amending and fertilization until the spring. To summarize: add some mulch to your gardens, rake the leaves off the lawn, and plan your soil amendments for the spring.
Protecting tender plants
It is the nature of most gardeners that they want to push the limits and try to grow plants that are considered tender in their respective climate. Things such as banana plants, elephant ears, taro, and others struggle to make it through our local climates. But often it’s not the extreme cold snaps that get them, it can be winter wet and/or the freezing and thawing cycle that happens when you grow in pots and live in a variable climate. So, have a good think about what plants you have and how you can overwinter them. Can you move a pot into an unheated garage? Is the plant small enough to dig up and bring inside for the winter? How about an awning to keep the plants from literally rotting in all our wet winter weather? If you live in a colder climate like the interior you might want to consider wrapping your plants, but be careful because you might just encourage rot instead. Wrapping trees and evergreens with burlap and blankets is really something that is best done in very cold climates and often is related to wind and snow damage. If the temperature dips really low below freezing you might want to consider wrapping your containers and yes, I do mean the pot not the plants. What often kills container plants is the freezing and thawing, by wrapping the pot you are insulating the plant roots from this process. If you think you may have specific overwintering concerns head down to the local GardenWorks and talk to one of the experts who can recommend the right course of actio
Lifting Summer Bulbs
Many summer bulbs such as dahlias, and tuberous begonias have a real hit or miss track record with overwintering in our climate as well. Many gardeners prefer to subscribe to the “sink or swim” mentality and leave their bulbs in to fend for themselves (it’s always a good excuse to try something new if the odd one doesn’t make it through). Other gardeners will put in the time to lift and store their bulbs. If you want to give it a try then wait until the top growth has died back, carefully dig them up and let them dry in a cool, dry place. Never wash them or get them overly moist as this will encourage rot. Wrap them in some paper and store them in a cool dry place until next spring.
General Non-Plant Clean-up
The last thing you should consider as you put the garden to bed is all the non-plant stuff. Make sure to pack up and/or cover your furniture, this will do wonders for increasing the longevity of your pieces. We are quick to invest in beautiful outdoor furniture so let’s not forget to take care of them properly. Also don’t forget to drain and store your garden hoses and watering wands/nozzles. This goes for irrigation and drip watering systems as well. If you have water in these and it freezes then it can cause ruptures. I have a small drip irrigation system and find that as long as I allow it to drain and keep it disconnected through the winter is comes through just fine. But if you have a more substantial irrigation system you may have to get it blown out. The last thing to do is to clean and pack away your stakes, tomato cages and various trellises.
It sounds like a big list of to-dos, but find some dry days and take some time outside to tackle a few tasks. It seems we may all have more time than we thought at home this fall/winter so let’s make sure to get outside and start the preparation for next spring. Then we can get cozy inside for the winter knowing we have set ourselves up for success and we can start to dream of starting seeds in January.
Written by: Ingrid Hoff