After the heat of the summer, gardening in the fall is a special delight.  Not only are the temperatures cooler and the sun still warm enough to please, but the rush of watering, planting, and weeding relaxes into a less frenzied state.  Now is the time to set the stage for next year.  Yet, if all the chores do not get done, there is always early spring to finish.  Use the following ideas as a check list for your fall gardening activities:

Garden clean up is important at this time of year especially if disease and/or insects were an issue during the summer.  Fungal diseases such as powdery mildew, Marssonina leaf spot, rust, black spot and others can over winter on leaf litter.  Carefully rake up all diseased foliage and dispose of it in the landfill, not in the compost bin.  Remove dead plant material from the vegetable garden as well.  Carrots, spinach, turnips, beets, and other cool season crops can be mulched in and left until needed.  Other crops should be pulled out so they do not provide winter cover for insects.  The soil of the vegetable garden can be turned in the fall and one to two inches of good compost added. If using a manure be sure that it is well composted. The winter freeze and thaw cycle will help mellow and mix in compost as well as break down stubborn clay clods.

Give the garden a final good weeding.  Perennial weeds such a bind weed can be treated with a glyphosate type herbicide up until hard frost.  The chemical moves more readily into the root system during the fall months compared to the active growing season when the top growth takes precedence. This type of herbicide is non-selective and should be used carefully.  It will kill anything it contacts. Annual weeds need to be removed before their seeds are scattered to start next year's infestation.

Cut back most perennials except those that provide winter interest or seed for the birds. Some perennials are best left with their top growth intact during the winter.  This protects the crown from dessication.  Rudbeckia (Black-eyed Susan), Echinacea (Coneflower), Sedum (Stonecrop), Buddleia (Butterfly Bush), Artemesia (Sage), Lavendula (Lavender), Agastache (Hyssop), and Achillea (Yarrow) are examples of plants that can be left alone until spring.  Ornamental grasses are beautiful in the fall and winter.  Cut these back in March before new leaf growth begins.  Mark perennials that you want to dig up and divide in the spring so that you remember where they are.

It is not too late to plant winter pansies even in October, as long as the soil can be worked.  Once the plants are properly established, pansies take very little care in the winter.  Choose a sunny spot.  Water during the mild winter spells when the soil is not frozen and the moisture can percolate into the soil.  Spring blooming bulbs are best planted in October and early November when the soil temperatures have cooled.  Once the soil has frozen, poppy, viola, pansy, linaria, pot marigold, sweet alyssum, and other early season annuals can be seeded.  Just scatter the seed and wait for Mother Nature to do the rest.

Remember to empty clay and ceramic pots so that the freeze and thaw during winter will not crack them.  Some pots are better stored in the garage or shed.  Others are tough enough and ornamental enough to remain empty outside. This adds add a touch of charm to the winter garden.

When raking leaves, consider saving some bags to add to the compost pile next year.  Recycle what you can not use.  Mulch your garden beds once the soil has frozen.  Shredded wood products or leaf compost makes good mulch.  This winter remember to water.  Newly planted trees and shrubs require special attention.  Yet, even established landscaping needs water periodically in the winter if natural precipitation is low.

Sometimes plants are purchased at the end of the season but not planted right away.  If you need to over winter potted plants, bury them (pot and all!) in the vegetable garden or another temporary space.  Mulch them in and remember to water them occasionally.  Dig them up in the spring when the soil is workable and plant them permanently.

Along with these fall chores, remember to enjoy the bounty of your garden.  Decorate your house with the fruit, dried seed heads and grasses that are reminders of the season.  Enjoy the crisp autumn air and bright sunshine and start planning for the spring!

Q:  This summer I had a gray powdery substance on the leaves of several of my plants including lilacs, cosmos, zinnias, etc.  Is there anything I can do for this now to prevent the problem next year?

A:  This is a fungal disease called powdery mildew. It is most often found on the upper surface of leaves but can also affect young stems, flowers and even fruit. Young succulent growth is the most susceptible.  Each type of mildew is found only on a specific host plant. The fungi overwinter on dead leaves and plant debris and then spread as spores to new growth in the spring.  The best prevention is to be sure that as many infested dead leaves, stems, etc. as possible are cleaned up in the fall and destroyed.

Q: The needles on the insides of many of the branches of my Austrian pine are turning brown and dropping.  What is causing this and what should I do for it?

A:  Pines naturally lose their inner needles during this time of year. This process is normal and called “casting”.  Some of the older, inside needles turn brown and are shed or “cast off”.

Q:  It seems like my golden delicious apples are pretty late getting ripe this year. Is this normal?

A: Yes, golden delicious is one of the late apples so it is not unusual for them to be getting ripe in October.  If you go to pick your apples early in the morning and find they have frost on them, postpone picking until the frost has melted off the apples.  Picking apples with frost on them can result in bruising.

Q: My bluegrass lawn received very little water this summer and is coming back now looking quite good.  I didn’t fertilize during the summer.  Should I fertilize now for fall?

A:  Bluegrass lawns benefit greatly from fall fertilization.  At this cooler time of year, top growth has slowed so nitrogen applied to the lawn will be better utilized for root-growth.  Choose a fertilizer with a ratio of 1# nitrogen/1000 square ft. of lawn and apply according to directions while grass is still green.

You can save quite a few dollars by using seeds gathered from your own garden.  Better yet, swap seeds with a friend.  You will both get quite a variety and they will be really special coming from a friend.

As your sunflowers dry, don't forget to put them out for the birds/squirrels.  Simply cut them, hang them upside down and watch the birds flock to them for a cool season snack.

Spring blooming bulbs can be purchased and planted this month.  For a fresh look in a sunny spot, try something new such as foxtail lily, Greek windflower, or spider lily.  These will be a breath of fresh air compared to the normal tulips, and daffodils.

The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

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This page updated:  October 18, 2003