Garden Guy: Autumn tasks in the garden

Photo courtesy simplysmartgardening.com

By Bruce Bennett

I don’t usually write Tasks-of-the-Month type articles. But, with this year’s unusual weather, more questions concerning tasks for the end of our most recent gardening season have been asked of me and we shall follow that path of discussion this month. 

My short answer to most inquiries for the last two months has been, “Yes, gardening for this season is nearly over AND there are still several tasks which can be completed now in order to make your initial spring gardening efforts easier to manage.

First, clean-up garden debris. This is especially true for a vegetable garden. The remnants of herbaceous plants, leaves, stalks, etc., should be removed and added to the compost pile. If the plant was diseased or infested, put it in the yard waste container for removal. Our home compost piles simply do not generate enough of their own heat to destroy all overwintering insects and pathogens. After cleaning the beds, spread some (1”-3”) of compost on the area and let it fuel next spring’s growth. Time permitting, digging-in this amendment will help to loosen the soil for next planting cycle.

Leave the seed heads for the birds
Photo courtesy extension.unh.edu

In the perennial beds, leave the stems of flowers in the garden as well as some leaf litter on the ground. The stems and leaves provide habitat for overwintering beneficial insects, amphibians and reptiles. Again, if there were issues with disease, this plant debris should be thrown away. 

Also, remember to leave the seed heads of grasses and perennials for your winter birds (think Echinacea and berry-bearing plants). Sanitation is always the best and least costly way to reduce next year’s disease problems.

For soil-level planting beds, now would be good time to edge beds. The rain will have softened the soil to make the job easier. Doing it now, in the slow-season, will alleviate the chore from the busy springtime. When the weather warms again, all that will need to be done is a final bed early-season clean-up and, if needed, the addition of a fresh layer of mulch and, I suppose, the addition of some new plantings you saw at the NW Flower and Garden Show. When edging, use a square tipped shovel. This will give you a nice, clean cut.

Bulbs can still be planted
Photo courtesy americanmeadows.com

Remember to take advantage of end-of-season sales that may still be going on in favorite garden centers. Seeds may have a lower germination rate, but will still grow quite nicely. 

In our USDA Zone 8, bulbs can still be planted. Inspect them for firmness before planting. Do not allow them to touch when in the ground. Crocus, alliums, tulips and hyacinths are especially easy to survive a late fall planting. Same spring color impacts with a smaller outlay of cash.

Because our ground hardly ever freezes or does so to a very shallow depth, shrubs and trees can still be planted and actually do better than if planted in spring. Roots have a longer bit of time to develop before stressful weather affects them. Remember not to install the plant any deeper in the ground than it was in its growing container. 

If planting an individual specimen, backfill with the native soil that you took out of the hole. However, if you are planting an entire bed with multiple plants, adding a couple of inches of topdressing compost to the bed and working it in as plants are installed is an easy initial slow-release fertilizer process. 

Keep these newly planted perennials, shrubs and trees watered until the winter rains take over the skies. Often, the death of an autumn- planted shrub or tree is due to our lack of watering, not problems with the plant itself. A general rule of thumb is that the plant needs one inch of water per week, either through rainfall, or garden hose.

Cover your fish pond with netting
Photo courtesy pondexperts.ca

If you have a garden pond that contains fish and water plants, covering the area with netting may be a good task autumn. 

The netting will keep leaves out of the water as well as also keeping blue herons and raccoons from a robust smorgasbord. Once the pond lilies and other plant cover is gone, there is little to protect the fish. Think about adding a tarp over just a portion of the pond.

Hopefully, all your tender plants have been dug up. If not, elephant ears, cannas, callas, etc. should be dug up and stored in a cool, dry location for the winter. 

Tropical plants, like hibiscus, citrus, Norfolk Island pine, and other houseplants should be inside by the end September. 

When bringing them in for the winter, check them for insects. Mealy bugs, aphids and scale like to come in where it’s warm. Particularly check in the leaf axils, stems of the plants and surface of the planting mix. Use an insecticidal soap or an all-seasons oil spray for houseplants before bringing them in. Once they are inside, check them, at least, monthly.

Keep a garden journal
Photo by thisismygarden.com

And in your down time this November, make notes as to what was successful in the garden and what was a failure. Determine whether the failures were due to weather, bad placement, or just improper care. 

Question the successes – did the plants do well because of the rain? Or the sun? Or the attention given to those particular plants? This will help in planning for next year’s garden, whether it’s the vegetable garden, perennial garden, containers, or shrubs and trees. 

Keeping a garden journal becomes a great tool throughout the gardening season in those successes and failures. It is the first reference book used when ordering seeds and choosing plants for next season’s garden.∂∂∂ƒSo there’s lots that still needs to be done before calling the garden season over. 

Outside chores abound, from planting, edging, cutting back and turning compost, to preparing for indoor gardening – growing holiday plants and forcing bulbs. 

Preparing for the holiday decorations becomes a "top of the list" as we approach the end of the month. Enjoy all things gardening, grow plants and enjoy the month of Thanksgiving! Happy gardening all!

Garden Guy Bruce Bennett

Contributing columnist, Bruce Bennett, is a Master Gardener, garden designer and lecturer. 

If you have questions concerning this article and your own landscape or care to suggest a gardening topic for a future column, contact Bruce at gardenguy4u@gmail.com.