October tips for the Perennial Gardener

This article was originally written for the Hull Garden Club (Hull, Massachusetts, Zone 6b) by Julie McIntosh Shapiro, and has been edited and reprinted here with the author's permission.

This is the time to plant garlic, shallots, and rhubarb not to mention one of the best times to plant deciduous shrubs and trees, taking care to never leave an “anthill” of mulch around the tree, keeping it away from direct contact with the trunk, but an even 2” layer to benefit and protect.

While we’re speaking of planting trees and shrubs, be careful to remove grass around these saplings, as it only competes for the nutrients, but most of all, the water. Remember to water, water, water and that it takes a good two years of care post-planting to care for a tree correctly. Now is also a good time to prune dormant trees and shrubs. Have you found some empty suet containers hanging up in those trees?  Well, within the month might be a good time to wash feeders out and give them a good scrubbing with a biodegradable cleaning product and begin to feed and water the birds again. Our New England bird species care more for us feeding them in the winter, when food is scarce, then during the spring and summer months when they can feed on their own. I have heard just lately of the troubles of the new arrival “flatlanders” to parts of Vermont, where summer and off-season bird feeding is attracting the attention of bears. I think that feeding birds in the wintertime is the best option, don’t you?

Now might be the last times this gardening season when mowing, edging and weeding are really necessary, plus don’t forget that a good couple of bushels of compost might be lifted from your compost bins, should you have one. Do not add this compost or mulch, which may suffocate your perennials, until the ground has frozen.

When the phrase, “putting the garden to bed” is heard, we know it’s Fall. In a 1998 Garden magazine article on fall clean up, writer Rita Buchanan poses these practical questions: "What parts of your garden please you the most? Where could you add some variety, improve the color scheme, fill a gap, or adjust a shape? What plants should you move? Are there some plants you should throw away? Where could you start a new bed or border? What structures or ornaments could you build or buy to add interest to your garden?" Look at those photos you took of your gardens this season and examine what went wrong and what went right, and most especially, what you need more of next year.

Pull out those straggly annuals and begin cutting back and dividing lily-of-the-valley, iris and daylilies, perennials (although I love to leave my Echinacea’s as they look so wonderful covered with dollops of snow in throughout the winter), and ornamental grasses (unless you want to leave them tall through the season), but hold up on the Caryopteris, and lavenders till the spring when you can see the growth appear. Remember, cutting plants back or leaving them alone throughout the winter does provide food for animals as well as creating interest on your property.

Before I get too far a field, I want to be sure to answer a question I received last month from Mary D. about what plants to choose for a steep hill?

For this climate (Zone 6b), plantings on steep hills, banks, or sandy slopes may need extra consideration, as erosion is a major factor. Erosion mats can sometimes handle this, till new plantings have generated a larger root system. There are also new systems for aiding this kind of planting that involve spraying a paper maché-like coating on the slope. Obviously, those experienced in planting in these tough areas should perform this procedure.

Regardless, you will want to get a soil sample before planting-in plants that will survive, to eliminate the chances of seasonally replanting, thereby destroying the delicate area. Due to erosion, runoff, and the coastal location, most soils lack organic matter and nutrients, and these may have to be added.

You did not mention the light requirements in your question, so I will assume that Sun is involved. Groundcovers that may do well for sunny areas here are: Cerastium tomentosum (Snow-in-Summer), Vinca, Artemesia (Dusty Miller), also short grasses like Festuca (Blue Fescue), shorter ground-hugging Sedums, ground Phlox, and Ajuga may also fit the bill. You may want to anchor larger plants for the eye and the area, and these might be: Panicum (grasses), Solidago (Goldenrod), Rudbeckia (Black-eyed Susan), and Yucca. Larger still are the small trees, shrubs, and evergreens such as: Ilex glabra (Inkberry), Bayberry, Rugosa Roses, Juniper (Juniperus noris ‘Lime Glow’), Crambe maritima (Sea Kale), Pinus thunbergiana (Japanese Black Pine), Pinus nigra (Austrian Black Pine), and even the wonderful Sumac, Rhus ‘Low Gro’. You may even want to try Hydrangea arborescens. This Hydrangea has a suckering habit (good for erosion control), and 5-6" flower panicles, but it’s hard to find in the trade.

Watering and irrigating this area should be a primary concern, unless you want to use plants that are tolerant of drought. There have been minor studies of some hybrid perennials escaping long periods of drought, they are: Salvia officinalis ‘Rachel’s Gold’ & ‘Pagona’, Dianthus ‘Brilliant Star’, Zebrinus ‘Little Zebra’, Potentilla ‘Pimento’, the rose, Rosa ‘Knockout’, Sedum ‘Autumn Spire’, and Knautia ‘Morris Midget’. With this information, you can be better assured of success with your “steep hill planting”.

For Garden Clubs, October is a wonderful month to assess all the garden beds and jot down any ideas for planting design and materials for next season.

HOW THINGS HAVE CHANGED

It used to be people would save their Ruby Begonias from their gardens and overwinter them inside for transplanting the following year. This no longer occurs, in large part to their relative cost versus availability at the "Big Box" stores. How things have changed.

 The whole subject of the planting of annuals and their temporary existence versus perennials and their relative semi-permanence is a current topic of discussion these days.

So why is it in the Garden Club, with the Garden Bed Islands throughout town of Hull, MA, members break their backs to replant these islands with annuals, just to return the following year to replant again? When do we move to planting, and better yet, planning beds with perennials suitable to our wonderful ecosystem (floods, tides, salt-spray, snow, ice, freezing temps oh, and the wind)? We could get to the point of just "popping in" annuals for little bursts of color here and there and let the perennials take care of themselves.

As I was walking in Boston this past July, down by 200 Berkley Street near the Boston Public Library, I noticed the Houghton-Mifflin Publishing Company's raised garden beds. For the first time I could remember these beds, which had previously held annual plants, now had shrubs and perennials of lovely blues, greens, creams and gold’s, from Hosta, Juniper, Yew, and Lady's Mantle. How things have changed.

These perennials and small shrubs are expensive to purchase of substantial size. However, there are reputable mail order outfits that will sell perennial "plugs" (2 inch plants) for little more than an annual, and with care, these plants may last for as long as 8-10 years!

So now that the professional garden landscaper, for whatever reason - monetary or otherwise is beginning to realize that perennials may be the way to go, how about us? - How things have changed.

Your Houseplants will have to come in shortly, as well as your glass rain gauges and frost-sensitive pottery. As temperatures begin to drop, you’ll want to have them washed, and inspected for insect damage before the thermometers reach a constant 50-55°. Most fertilizing should stop until next March, to let your plants rest during the winter months. It’s a nice idea to pot-up chives, parsley, and rosemary for use inside throughout the winter, and save some of them from a horrible fate.

Here’s a lovely recipe for Roasting Pumpkin & Squash Seeds: wash and dry seeds well, then lay then out onto an oiled baking sheet in a single layer. Drizzle a bit more oil and some kosher salt over the seeds. Roast in a 250-degree oven until crisp and brown.

In suggesting a garden book to read through, I’m recommending the wonderful, insightful, and oft times opinionated passion of a great British plantsman, Christopher Lloyd and his book, Garden Flowers, recently published.