Hopefully this guide will help you with fall clean-up and
winterization tasks. It’s laid out to
guide you through each type of garden, or plant group, and includes information
about how to accomplish each task and what tools and products will make your
job easier.
Annuals,
Vegetables, and Tropicals
Once fall arrives and your summer annuals start looking a
little tired, it’s time to remove them and either plant fall annuals like mums
or prepare the beds for winter. If you
plant mums, these tasks will apply when they are done blooming as well. Pull all the dead annuals out of the ground
and get rid of the debris. If you compost, add any pest and disease free
material to your pile and turn it like normal.
If you had pest or disease problems, dispose of debris in the trash or by
burning. You don’t want pests and
diseases over-wintering in the garden or in the compost pile. Pull or spray any weeds that remain. Soil can erode over winter so I mulch with a
thin layer of straw or leaves at this time. Straw breaks down fairly
quickly so in spring I will either plant new annuals right through it or work
it into the soil when I prepare the bed.
In the vegetable garden; perform the same tasks. You can plant a fall cover crop to keep soil
in place over winter or you can mulch with straw or leaves. Fall cover crops act as a green manure and
get tilled into the bed in spring. If
you mulch with straw or leaves, that material can get tilled in during spring
prep as well.
If you have tropical plants that you will bring in for
the winter, now is the time to apply a systemic houseplant insecticide, clean
up any damaged or dead stems, and bring them in. Place them in a location appropriate to the
type of plant. Most tropicals prefer a
south or east window.
Now is also the time to dig and store tender bulbs like
Dahlia or Canna for the winter. Dig them
up and let the foliage dry on the plant for a few days. Once the foliage is dry, cut off the stems
and foliage and place the bulbs into a paper bag or open plastic bag and put
them in a cool dry place like the basement.
Perennial
Gardens
Fall is an important time for plants to get ready for
winter. They are busy storing nutrients in their root systems to survive
the winter. It’s important to let plants go dormant naturally. If
you cut them back too early, you deprive them of energy to get through the
winter. You can do perennial clean up in late October to late
November. Cut any perennials that don’t offer winter interest back to
ground level. Grasses, butterfly bush, mums, Russian sage, perennial
hibiscus, coral bells, and Caryopteris all benefit from being left alone for
the winter. Cut those plants back in early April.
While it’s just fine to do perennial garden clean up in
fall, there are benefits to doing it in spring. Many animals including
insects, birds, and mammals will use a well planted perennial garden for cover
or food in the winter. Many perennials provide winter interest thanks to
interesting seed heads. It’s ok to do
cleanup in spring rather than fall. The exception is if you had a serious pest
or disease problem on certain plants. Clean up those plants in fall
and dispose of the debris in the trash to minimize those problems next season.
Shrubs
Fall pruning is often recommended; but it would be better
to call it “late summer” pruning. Plants need to heal from pruning before
winter sets in; if you prune too late they can suffer winter injury and you
will need to do more pruning in spring. You generally want to finish any
pruning by mid-August. The exception would be any spring blooming plants,
which should be pruned by mid-June to allow them time to form new flower
buds for next spring.
Young trees have thin bark which can be damaged by
rodents, rabbits, or deer in the winter.
Use a plastic trunk wrap to protect young trees for a few years. Wrap the trunk in fall and remove it in April
or May.
Fall is the time to take the first step in pest control
for fruit trees as well. After all the
leaves fall off make sure to rake them up and dispose of them. After the leaves drop is also a good time to
apply dormant oil, which smothers any insects or fungus spores that would over-winter
on the branches or trunk.
I get a lot of questions about Hydrangea pruning.
Different types of Hydrangea need to be pruned differently. The
macrophylla types that have colorful flowers like pink or blue should be pruned
in spring when they start to leaf out. Only remove dead wood; they will
leaf out on old stems and bloom best on that growth. The old fashioned
‘Annabelle’ types that look like giant snowballs bloom on new growth. They
can be left to leaf out on old wood or get cut back to the ground in
spring. This includes newer varieties like ‘Incrediball’, ‘Bella Anna’,
and ‘Invincibelle Spirit’ as well. The paniculata types like ‘Limelight’,
‘Strawberry Vanilla’, ‘Quick Fire’, ‘Limelight’, etc and the oak-leaf
hydrangeas don’t need much pruning. I only prune for structure and to
remove spent blooms, which I typically do in spring as the dried flowers offer
winter interest. If you need to prune for structure or size, these types also
bloom on new wood and pruning can be done in spring.
Roses
For roses that need winter protection such as the hybrid
tea, grandiflora, or floribunda types, prune off only what you need to in order
to protect them for the winter. The goal with protecting your roses isn’t
to keep them warm, but to protect them from temperature fluctuations, thawing
and freezing, and dry winter air.
The most common method of winter protection is the
old-fashioned rose cone. If you haven’t seen these, they are styrofoam
covers to go over your roses for the winter. They should be put on when
we start to stay frozen, usually around Thanksgiving. It’s important to
make sure your rose cones are vented; the ones we sell have vent holes in the
top for warm air to escape on sunny winter days. Make sure to mound some soil
or mulch around the graft union of the rose at the base of the shrub. This will further protect your rose bush
through the winter.
Like other shrubs, pruning roses late in the season
can lead to winter injury. A good method of winter protection is to build a
cage around the rose bush with hardware cloth and fill it with oak leaves,
mulch, or compost. This method allows you to protect more of your rose
without pruning any stems off. If some stems stick out of the top of the
cage that’s ok. They may get winter damage, but that can be pruned off in
spring.
A third method for protecting roses through the winter is
to not even plant them in the ground. Instead, plant them in a 12-14 inch
pot and sink that pot in the ground for the
summer. Around Thanksgiving, pull them out of the ground,
pot and all, and place them in the garage. Give them 1 cup of water
every month starting in December. This keeps them from drying out over
winter and the garage will keep the temperature cold but stable. This is
a great method to use for rose trees which are otherwise difficult to
protect for winter.
Another method of protecting rose trees is to completely
dig them up and then dig a trench about 12” deep and lay them in it. Cover with soil or compost for the winter and
dig them up again in late March when the ground thaws.
Climbing roses often need protection as well. The best method is to unfasten them from
their support and lay them down. If they
are very tall you can prune them back a bit to make this task easier. Once laying down you can cover them with
compost and mulch or evergreen boughs.
This keeps them insulated for the winter.
Weed
Control
Another important task for fall is weed control. Just
like the perennial plants in your garden, perennial weeds are storing a lot of
nutrients for winter. This makes it an excellent time to spray
herbicides, since the plants take in more chemical than usual. It’s also
important to hand pull any weeds before they go to seed at this time.
Roundup (or any product containing glyphosate) works well on pretty much all weeds. They are broad-spectrum herbicides, which
means they will kill pretty much any plants they come into contact with so be
careful to avoid accidentally spraying garden plants.
A more selective herbicide is Grass B Gon. It kills only grassy weeds like crabgrass and
quackgrass. It’s still important to avoid
contact with garden plants since damage can occur to leaves and flowers. It can also damage or kill ornamental grasses
or your lawn. If you aren't sure if
damage will occur, do a test spray and apply a small amount to a single
leaf. If browning or discoloration
occurs try to minimize contact with that plant.
It’s also a great time to kill weeds in your lawn. Apply a liquid formulation of Weed B Gon to
turf grass areas at this time to reduce how many weeds you have in spring.
It’s important to ALWAYS read the entire label of a
pesticide and apply according to label instructions. Failure to do so may result in your gardens
being damaged. Not only that but you
could harm yourself, your children, or your pets. So follow the directions and be safe.
Lawn
If you only fertilize your lawn once during the season,
research has shown that fall is the best time to do it. Using a winterizing fertilizer helps build a
strong root system for the turf to overwinter and get a strong start in
spring. It’s also a great time to apply
soil building fertilizer products such as Mag-I-Cal or Love Your Lawn, Love
Your Soil, both from Jonathan Green.
These products feed the soil microorganisms which in turn feed your
lawn.
It’s also a great time to seed new lawn areas or over-seed
thin areas of your lawn. Turf grasses
like cool weather and will establish well before winter. The cooler temperatures in fall also means
you have to do less watering. If you’re over-seeding, use a spring rake to
loosen the soil surface so the seed can germinate and root in well.
Final Fall Tasks
Fall is also a great time to renew your mulch. A fresh
layer of mulch not only looks great, but helps conserve moisture, cut down on
weeds, and insulate your plants for winter.
It’s important to continue watering your plants through fall
until we freeze. Even though deciduous plants aren't actively growing,
they do continue to store water and nutrients until the soil freezes. And
evergreens will continue to photosynthesize and grow anytime the temperature is
above freezing. Going into winter with the proper amount of moisture helps
minimize winter damage. If rainfall is scarce this autumn, make sure to
irrigate. Plants won’t use as much water, but the soil should never be
very dry. A good rule of thumb is to irrigate 1 inch of water per
week.
Wilt Stop can help reduce winter burn on evergreens. Make sure to apply late in the fall when temperatures
are above freezing. If you apply earlier
and growth hasn't fully hardened off damage can occur when temperatures reach
freezing. Another way to prevent winter burn is to build a burlap screen or cage
around susceptible plants. You don’t
want to wrap plants tightly, they still need air circulation and some light,
just a loose cage or screen around them is sufficient. Pound stakes into the ground and use staples
or twine to secure the burlap to the stakes.
Following these basic recommendations will ensure your
landscapes are well-protected throughout the winter and, therefore, be more
healthy and fruitful next spring.
