General Horticulture • HO-93-W
Department of Horticulture
Purdue University Cooperative Extension Service West Lafayette, IN
Autumn Garden Calendar
by B. Rosie Lerner
Timing horticultural events and practices can vary • Reflower last year’s poinsettias for this year’s
from year to year, depending on weather condi- holiday by providing complete darkness for 15
tions. The following information is intended as a hours daily beginning about October 1 until
general guide. Regional differences are noted about December 10.
when practical. Adjust activities according to local
weather and site conditions. Be sure to read label October
directions thoroughly on all products. • Pot-up spring-flowering bulbs with tips ex-
posed, to force into bloom indoors. Moisten
soil and refrigerate 10 to 13 weeks. Transfer
Indoor Plants and Activities to a cool, sunny location, and allow an addi-
tional three to four weeks for blooming.
• Water indoor plants less frequently, and
• Prepare storage areas for overwintering
discontinue fertilizer as plants slow down or
tender flower bulbs and garden produce.
stop growing for the winter season.
• Thanksgiving (or Christmas) cactus can be
forced into bloom in time for the holidays.
• Move plants closer to windows or to sunnier
Provide 15 hours of complete darkness each
exposures, such as west and south facing
day, such as from 5 p.m. to 8 a.m., for
windows, if plants are dropping many leaves.
approximately eight weeks. Keep tempera-
Artificial lights may be needed to supplement
ture at about 60˚ to 65˚F. Temperatures of
particularly dark rooms.
55˚F will cause flower buds to set without the
• Continue dark treatment for poinsettias by
keeping them in complete darkness from
• Dig and repot herbs or take cuttings for
5 p.m. to 8 a.m. until early December, or until
growing indoors over the winter.
red bracts begin to show.
• Store leftover garden seed in a cool, dry
place. A sealable jar with a layer of silica gel Woody Ornamental Landscape Plants
or powdered milk in the bottom works well. and Tree Fruits
• Bring houseplants that were moved outside September
for the summer back indoors before night • Fall is a good time to plant many container-
temperatures drop below 55˚F. Gradually grown or balled-and-burlapped nursery stock.
decrease the amount of light to acclimate the Prepare a good-sized hole, plant at the same
plants andhelp reduce leaf drop. Be sure to depth it grew in the nursery, and water
control insects and diseases before putting thoroughly. Mulching will help protect against
the plants near other houseplants. large fluctuations in soil temperature and
moisture. Be sure to stake or guy-wire tall
plants to protect them from strong winds.
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General Horticulture • HO-93-W
• Do not be alarmed if your evergreens, particu- • If you are planning to order a “live” Christ-
larly white pine and arborvitae, drop some of mas tree, prepare its planting hole before the
their older needles. All evergreens shed soil freezes. Mulch the area heavily to
needles at some time, but not all at once as prevent freezing, or dig the hole and put the
deciduous plants do. fill in a protected, nonfreezing area, such as
a garage or basement.
• Harvest apples when flavor is sweet but
before fruits soften. Lawns
• Harvest pears when the dots on the skin begin
to turn brown. Pears are best ripened to September
yellow off the tree. • To promote the lawn’s recovery from summer
stress, apply high-nitrogen fertilizer at the rate
• Clean up fallen fruits, twigs, and leaves around of 1 pound actual nitrogen per 1,000 square
apple (including crabapple) and other fruit feet.
trees to reduce disease and insect carry-over.
• Mow lawn to maintain a 2 to 2 1/2-inch
October height, removing no more than 1/3 of the
• Keep plants, especially newly planted stock, height of the grass at any one time.
well-watered until the ground freezes.
• Leave clippings on the lawn or add them to
• Have soil ready for mounding roses for winter the compost pile.
protection. Do not mound or cover the roses
until after leaves drop and soil is near freezing, • Vertical thinning or power raking of the lawn
usually in late November or early December. will help control thatch build-up, if needed.
November • Reseed bare spots or new lawns with a good
• Prevent rabbit and rodent feeding damage quality seed mixture.
by erecting physical barriers, such as metal
mesh (1/4") hardware cloth. Pull mulch • Early fall is a good time to apply broadleaf
away from the trunk a few inches because weed killers. Be sure to follow all label direc-
the mulch provides a warm winter home for tions, and choose a calm day to prevent spray
rodents. Chemical repellents are also drift.
available, but their effectiveness is tempo-
rary and not fool proof. October
• Rake the fallen leaves from lawn, particularly
• Prevent frost cracking (or sunscald) by larger-sized leaves, such as maple and
wrapping trunks with commercial tree wrap sycamore leaves; they can smother the lawn
or painting the south and southwest facing as they become wet and mat down. Raking of
sides of the trunk with white latex outdoor smaller leaves, such as honeylocust, is
paint. Young, thin-barked trees such as optional.
maples and many fruit trees are especially
• Late fall fertilizing can help keep the lawn
• Remove dead, diseased, or damaged green longer and boost early spring recovery.
branches. Although top growth stops when air temper-
ature drops to 45 to 50˚F, roots remain active
• Protect the graft union on rose bushes by as long as soil temperatures remain above
mounding soil up 12 inches around the 35-40˚F. Apply 1 pound actual nitrogen per
plants and adding mulch on top. Wait until 1,000 square feet of lawn.
after several killing frosts have occurred so
that plants will be dormant when covered.
Plants covered too early may be smothered.
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General Horticulture • HO-93-W
Flowers, Vegetables, and Small fruits • Cut flowers, such as strawflower, statice, baby’s
breath, and celosia for drying; hang upside down
September in a dry, well-ventilated area.
• Dig onions and garlic after tops falls
over naturally and necks begin to dry. • Dig and store tender garden flowers for winter
storage. Gladiolus corms should be dug when
• Dig potatoes with a fork or shovel and allow to leaves begin turning yellow. Caladiums, gerani-
air dry for a week or two and then store in a ums, and tuberous begonias should be lifted
cool (40-45˚F), dark location. before killing frost. Dig canna and dahlia roots
after a heavy frost. Allow to air dry, then pack in
• Plant radishes, sets for green onions, lettuce,
dry peat moss or vermiculite, and store in a cool
and spinach for fall harvest.
• Thin fall crops, such as lettuce and carrots, that
• Harvest grapes, everbearing strawberries, and
were planted earlier.
fall raspberries. For most fruits, flavor is the best
indicator of ripeness, although color change can
• Harvest crops such as tomatoes, peppers,
also be a good indicator. However, grapes
eggplant, melons, and sweet potatoes before
change color long before they are fully flavored,
frost, or cover plants with blankets, newspaper,
so sample the fruit to be sure.
etc. (but not plastic) to protect them from light
• Remove raspberry canes after they bear fruit.
• Harvest mature, green tomatoes before frost October
and ripen indoors. Individually wrap fruits in • Harvest root crops and store in a cold (32˚F),
newspaper, or leave them on the vine, pulling humid location. Storing produce in perforated
the entire plant out of the garden. Store in a plastic bags is a convenient and easy way to
cool location, about 55 to 60˚F. increase humidity.
• Harvest winter squash before hard frost. Skin of • Harvest brussels sprouts as they develop in the
the squash should be tough with deep, solid axils of the leaves from the bottom of the stem.
color. Some cultivars will show an orange blush Brussels sprouts will continue to develop up the
when mature. stem.
• Plant, transplant, or divide peonies, daylilies, iris, • Harvest pumpkins and winter squash when rind
and phlox. is hard and fully colored but before frost. Store
in a cool location until ready to use.
• Save plants such as coleus, wax begonias,
impatiens, or fuchsia for indoor growing over • Harvest gourds when stems begin to brown
winter. Dig plants, and cut them back about and dry. Cure at 70 to 80˚F for two to four
halfway, or take cuttings of shoot tips, and root weeks.
them in moist vermiculite, soil mix, or perlite.
• Asparagus top growth should not be removed
• Watch for garden chrysanthemums to bloom as until foliage yellows. Let foliage stand over the
days grow shorter. Some may already have winter to collect snow for insulation and mois-
bloomed earlier in summer, which will decrease ture.
the number of fall blooms.
• Remove plant debris from the garden to protect
• Plant spring-flowering bulbs beginning in late next year’s planting from insect and disease
September. Planting too early can cause bulbs build-up. Compost plant refuse by alternating
to sprout top growth before winter. However, layers of soil, plant material, and manure or
allow at least four to six weeks before the commercial fertilizer.
ground freezes for good root formation.
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General Horticulture • HO-93-W
• Carve a Halloween jack-o’-lantern.
• Complete planting of spring-flowering bulbs.
• Strawberry plants need protection from winter’s
extremes, but applying winter mulch too early
may cause crowns to rot. Wait until later in
• Have garden soil tested for fertilizer needs
every three to five years.
• Fall tilling, except in erosion-prone areas, helps
improve soil structure and usually leads to soils
warming up and drying faster in the spring,
thus allowing crops to be planted earlier.
• Apply winter mulch to strawberries when plants
are dormant but before temperatures drop
below 20˚F, usually in late November or early
For more information on the subject discussed in this
publication, consult your local office of the Purdue University
Cooperative Extension Service.
It is the policy of the Purdue University Cooperative Extension Service, David C. Petritz, Director, that all persons shall have equal opportunity and access to programs and facilities
without regard to race, color, sex, religion, national origin, age, marital status, parental status, sexual orientation, or disability. Purdue University is an Affirmative Action employer.
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