The problem with Pacific Northwest gardeners taking advice from national sources is that the timing of garden tasks here, as well as our gardening styles, are different. Each region’s climate dictates when we must, should, or don’t have to be occupied in the garden. In colder regions, the garden is frozen in winter; here in the Northwest, we have one or two cold snaps that, depending on their severity, may kill off some plants and force others into dormancy. In warmer climates, plants get even less rest than they do here.
Although in the Northwest the only year-round garden occupation is weeding, there are always activities we can find to do, which means we can spend a particularly beautiful day outdoors in the garden even in winter. We can spread a winter mulch almost anytime during the dormant season, because there is seldom a snow cover that lasts for long. Because spring growth often begins before the official date of the spring equinox and we can see flowers late into fall, the Northwest garden always beckons.
A Glossary of Garden Maintenance Tasks
Gardening terms such as cut back, cut down, pinch back, shear, and deadhead, left undefined, cause consternation among gardeners wanting to learn just how to take care of their plants. Here is what they mean:
Cut back: Cut off part of a stem. Do this when a plant is finished blooming, and you can encourage a second flush of flowers later in the season. When you cut a stem back, you cut below the last (finished) flower and just above where you see the potential for new leafy growth (often in the leaf axil, which is where the leaf joins the stem). You also cut back plants early in the season to encourage branching (such as Penstemon), to make them bloom when they are shorter (such as Campanula), or so that they don’t spread out, leaving a hole in the middle of the plant (as in Sedum ‘Autumn Joy’).
Cut down: Cut the stems close to the ground. This cleanup activity is done in the dormant season or with plants that go dormant during the growing season (Oriental poppies, for example).
Pinch back: Take the stem off, but only as far down as the first or second set of leaves. This is often done on new growth, which is tender enough to do with your fingers, hence the term pinch.
Shear: Indiscriminately and uniformly cut back, often using hedge shears. If you don’t want to play hunt-and-find with the spent Coreopsis ‘Moonbeam’ flowers mentioned under High-Maintenance Gardening Style (this page), you can shear the whole plant back a few inches.
Deadhead: This is not a fan of the rock band, but an activity carried out during the growing season. Cut off just the spent flowers. This encourages some plants to continue blooming. Pincushion flowers (Scabiosa) can be deadheaded for a longer blooming time.
How much work does a perennial garden require? The answer is: How much work do you want it to be? And, anyway, aren’t you a gardener because you love gardening?
No landscape is maintenance-free, except maybe artificial turf and plastic flowers. Having trees and shrubs means you rake leaves and prune. With perennials, you cut back to control growth, cut down spent plants, and groom plants after flowering. Those who prefer a garden as neat as a pin must cut back again, cut down several times, and groom constantly.
And what is your reward? The garden on a warm summer day. Both you and the bees hum lazily as you wander from poppy to rose to Rudbeckia. The bee is more industrious than you, collecting its pollen. You are more likely to end up like the resident garter snake, asleep on a rock in the sun. Make that a rock for the snake and a chair for you.
Maintenance tasks depend on the plant, so read about each plant’s care in Chapter Four, Perennials from A to Z. But there are general guidelines for upkeep, which we can discuss here.
Below are some ways of looking at a garden maintenance schedule. Your style will most likely fluctuate among these three scenarios, as fits of tidiness correspond to empty spaces in your calendar.
If puttering about in the garden is not a fulltime occupation for you, if you have little time to garden but love flowers, choose perennials with an evergreen presence, such as Mrs. Robb’s spurge, and evergreen grasses, such as the orange sedge (Carex testacea), and then accent with color from reseeding perennials such as toadflax (Linaria purpurea).
Perennials that need more than one thing done to them, such as the mourning widow, Geranium endresii ‘Wargrave Pink’ (it must be cut back in winter and cut back again after blooming), may not be for you. Perennials that need staking, dividing often, or treating regularly for any sort of pest or disease problem—no matter how lovely they are—are not for you.
For gardeners who love to be in the garden and don’t mind the work but still have a real job, the world is yours. Perennials don’t need the amount of work some people think: an hour or two of tending a week, cleanup at the appropriate time of year, and let the garden do what it does best. For you, the best plant support is another plant, so you don’t spend time staking and tying. And remember that the seedheads you leave on the phlox and goldenrod provide perching places in winter for finches, chickadees, and bushtits. Your garden is enjoyed by everyone.
You spend every possible waking moment in the garden and think nothing of spending half an hour snipping off the spent blossoms of Coreopsis ‘Moonbeam’ so that the new flowers will show to their best effect. You like to keep a tight watch on plants. No flopping is allowed in your garden, so plant supports go in early for peonies and delphinium. Daisies and sedum get cut back by a third to a half in May so that they will stand at attention when in bloom later in the summer. There are no “messy” plants for you, because you are on top of cleanup. Brown stems might as well be outlawed.
The rains taper off, the sun peeks out again, and we are drawn, inexorably, to the out-of-doors. There’s so much that we want to do in the garden that we find ourselves constantly distracted. We head outside to weed one corner of the garden but see the emerging stems of astilbe and stop to take a look. We find that a little cleanup is in order here, so that we’ll be able to admire the frothy pink flowers later on. Did we forget to clean up the old hellebore leaves? Wouldn’t this be a great place for that new Epimedium that’s waiting on the front porch? Soon our original goal is forgotten, and we happily lose ourselves in whatever is at hand.
In spring, the gardener wants to get things in order. Spring planting proceeds apace, especially because there are plant sales every weekend offering choice selections from specialty nurseries, and full-service nurseries are stocking shelves with delectables.
wallflower (Erysimum ‘Julian Orchard’)
Your garden’s daffodil show was beautiful in late February and early March, but now you’re getting just a little tired of all the daffodil foliage. You know you aren’t supposed to cut it back—the leaves are photosynthesizing and sending food down to the bulb, creating energy for next year’s show. Most experts advise against braiding the foliage, as this can damage the leaves, which then won’t be able to photosynthesize. Instead, carefully fold the leaves down and hide them under some big-leaved perennials and ground covers. Bergenias, coral bells, mounds of geraniums, and lady’s mantle can all help.
Fertilizer versus Mulch
We automatically reach for the fertilizer in spring. Don’t our perennials need a boost? What would they do without our annual application of fertilizer?
They would probably do just fine, and they might do even better if we lay off the fertilizer and rely on organic matter to do the job. Organic mulch provides enough nutrients for plants to grow well and flower, and it’s in only extreme cases that you may want to add to this by sprinkling on some fertilizer.
Perennials in pots do not have access to real soil and so may do better with a light dusting of some all-purpose organic fertilizer in spring. Some gardeners prefer to help along plants that need more acid or more alkaline soil, and so an amendment helps here, too. You may want to apply some dolomite lime to the hellebore planting hole (even just a piece of chalk) to increase the alkalinity, or sprinkle leftover coffee grounds around the lungworts after you’ve cut back the spent flower stems. But in general, the only fertilizer you need apply is a good mulch.
The big, wide, floppy foliage of hybrid tulips is harder to deal with. But showy midspring bulbs, including the giant Darwin hybrids, work best in pots anyway, because they don’t like any mollycoddling during the summer. Tulips in containers allow you to move them backstage at the end of their show, where they can spend the summer as dry as they like it.
There’s more to do in spring than plant. It’s time to be on the lookout for spring pests. Using mechanical controls and encouraging wildlife in your garden—a few of the garden helpers—keeps your perennials healthy at a low cost and with less work from you.
One of the worst spring pests is cutworms. These can eat up seedlings and many kinds of perennials that have a lot of basal foliage, such as foxgloves, before you know it.
Keep watch. Do you see leaves getting munched on? Dig around lightly in the soil or cut off the lowest leaves. Cutworms are grayish brown in color; they curl up in a “C” when disturbed. They usually feed at night.
The best cutworm control is immediately dispatching them with your trowel, weeder, pruners, or garden scissors. Go night hunting with a flashlight. Encourage predators of cutworms, which include birds and spiders. It might help to put the bird feeders close to plants that might be eaten by cutworms. Protect seedlings with paper collars that are pushed slightly into the soil; keep these on until the plants are big enough to fend for themselves. Larger plants may be disfigured but won’t be killed. Cutworms are a problem in spring but turn into moths later in spring.
And then there are aphids. They come in green, brown, or black and can cover the stems of succulent new growth on perennials as well as annuals and shrubs. In our mild maritime Pacific Northwest climate, aphids start early in the year and continue until cold weather. Some plants get aphids even in the winter. Aphids debilitate plants but don’t usually kill them outright.
baby’s breath (Gypsophila paniculata ‘Pink Fairy’)
pincushion flower (Scabiosa caucasia ‘Fama’)
Spraying insecticidal soap is a low-toxic way of controlling aphids, but it’s even easier to knock the aphids off with a sharp spray of water. Once knocked to the ground, they don’t return (it’s another generation that shows up next time). Keep aphid activity down by reducing or eliminating the amount of fertilizer you use. Overlush plants are an all-you-can-eat buffet to aphids.
Again, wildlife is your friend here. Birds, especially the little bushtits, can pick a stem clean of aphids. Soldier beetles, which are shaped like capsules and have black wing coverings and orange heads, feed on aphids. Ladybugs eat aphids, but ladybug larvae devour them. Ladybug larvae look like tiny black or black-and-orange alligators. Look up a photo of ladybug eggs, so that you won’t inadvertently destroy them. The yellow eggs are laid in clusters of ten to fifty, and look like little footballs standing on end; they are usually on the undersides of leaves.
The silvery sheen of a slimy trail leading to and from a ravaged Hosta can only mean one thing—the gardener’s nemesis has been at work. The brown European slug destroys succulent new growth of some of our favorite plants. (Northwest native slugs eat dead plant material and are not considered pests.) Chemical controls are not the way to go, as they are toxic to wildlife, pets, and children.
The most satisfying way of getting rid of slugs, of course, is to do the deed yourself, but you would have to be on slug patrol for too many months of the year. You could pay the kids a nickel a slug (make the kids wear gloves!). Beer traps—cheap beer in cat-food cans that are set on the ground—are effective, but rather unpleasant to empty. There are safe controls available on the market today, using pellets of iron phosphate. If you haven’t used one of these products before, you’ll be amazed at how well they work. No more holes in the hostas.
The different growing habits of perennials make for variety and visual interest in the garden. Some plants grow up, others out; some creep along the ground. And others flop. This is of great concern to many gardeners, who don’t want their Sedum ‘Autumn Joy’ to spread open in the middle. To stake or not to stake? Or is it possible to limit floppiness with pruners instead of stakes and string?
Saving Seeds
Want more granny’s bonnets? Wish your Welsh poppies were by both the front and back doors? You can save seeds from many of your garden perennials to share with friends or spread around your own garden. Seeds need to be fully ripe to be viable (able to germinate), and that means leaving the spent flowers alone until the seedhead looks dried out. You know when the seeds of the poppy are ripe, because you can shake the poppy head and hear them. Of course, you’re also shaking the seeds out through tiny holes, so do this over a bowl or into an envelope.
Save the seeds in a dry envelope or film canister in a cool, dark place. Or plant them out immediately in pots or in the garden. You may get some genetic variation in plants—such as varying flower colors—but that just adds to the interest. Here are some perennials that are easy to grow from seed:
1. rose campion (Lychnis coronaria)
2. jupiter’s beard (Centranthus ruber)
3. lady’s mantle (Alchemilla mollis)
4. granny’s bonnet (Aquilegia vulgaris)
5. tickseed (Coreopsis grandiflora)
Many plants can be cut back by one-third to one-half in spring to keep them shorter yet still allow them to bloom. Sedum, Eupatorium, and coneflowers (Echinacea) will all take cutting back and still bloom later. Cutting back can also be done just for controlling the bloom time and not the plant’s size. Garden chrysanthemum can be nipped back twice to make sure they bloom in late summer and not earlier. Globe thistle (Echinops) can be cut back hard after it blooms once and will flush out with new growth and a few more blooms. Cut off the old flower stalk of a delphinium and you’ll get more flowers.
But when it comes to floppiness, many gardeners choose to plant perennials close together and then allow them to have at it. This creates some surprising and lovely combinations at various times of the year. An orange tiger lily leans over into the catmint (Nepeta); a stem of deep maroon purple Knautia flowers wanders among the Crocosmia ‘Lucifer’. New pictures are created daily.
You need a rest. Let the summer garden take care of itself. But if you feel compelled to work, you can always deadhead. Cut the oriental poppies down when you’ve let the seed pods ripen. Spot-water the plants that need it in only the driest part of the summer—the mulch you applied in winter will be a big help here, reducing the need to water.
Visit other people’s gardens. Make mental notes about which plants to move and which new plants to buy when fall comes. Do this while sitting in a lawn chair with a cool drink in hand. Take a nap.
Yes, fall is a fabulous time to plant. The nursery pots that have been accumulating on your deck or porch all summer long, as you visit this nursery or that plant sale, can now go in the ground. The warm soil and autumn rains will encourage good root growth well into winter and get your plants off to a robust start in spring.
We hear way too much about fall cleanup. October and November may be a good time to clean up the garden in Minnesota, but there is still too much going on in our Pacific Northwest gardens. We must wait until late fall—that is, the first half of December—to cut back those plants that have died back.
Some disease-prone plants do best if their foliage and stems are removed as early as possible. This can keep peony botrytis at a minimum. But because the foliage of many peonies takes on lovely apricot tones in fall, you may want to delay the immaculate cleaning if you don’t have a botrytis problem.
soapwort (Saponaria ocymoides)
Remember that leaving the stems and seedheads of plants provides good habitat for birds. Finches perch on goldenrod. Bushtits hang upside down on a Japanese anemone. Chickadees flit through the penstemon. These birds are a great asset to our gardens, and it doesn’t take much to give them a place to hang out and eat.
The plants that you let go to seed over the summer may now have a flock of seedlings sprouting at their base. You can pot up seedlings of hellebores, columbine, lady’s mantle, and Welsh poppies now or during mild winter weather (see Dividing Perennials, below, for details). If you don’t plan on replanting the seedlings immediately, keep the pots in a sheltered place for the winter, or give them away to grateful gardening friends.
The dormant season—late fall and winter—is also a good time to divide plants that have become congested (which may lead to a lack of flowers) or are crowding out other plants. Look at the way the plant grows to figure out how to divide it.
Overwintering Perennials in Pots
It’s only the perennials in pots that you should have any concern for in winter, because those plants are susceptible to becoming waterlogged and/or freezing their most vulnerable parts when they are exposed to cold.
What kills containerized plants during winters in the maritime Pacific Northwest is wetness. Pots that sit flat on the ground—whether that’s a concrete patio, a wood deck, or the soil—are likely to accumulate too much water, even with the required drainage hole in the bottom. They can’t drain the rain quickly enough during our rainy winters. When the air spaces in soil that are vital to a root system’s survival are filled with water instead of air, the roots suffocate.
A dish under a pot is a good idea in summer. The water that runs out of the drainage hole sticks around to be reabsorbed. The air is dry, and the water evaporates instead of keeping the soil saturated. A dish under a pot in winter, however, turns the pot into a swimming pool.
So preparation for winter in the potted perennial garden includes taking dishes out from under pots and making sure that there is adequate space for drainage. Many gardeners buy cute pot feet and put three under each pot, successfully providing drainage by adding a couple of inches of space between the bottom of the pot and the ground. Special purchases do not have to be made for this winter accommodation, though; you can always set pots up on two boards or a series of bricks.
Or bring the pots in out of the rain. Moving the pots under the eaves may seem a daunting task if your container garden includes lots and lots of pots, but for a few containers (especially lightweight, faux terra-cotta), it’s within reason.
Another potential threat to plants in pots in winter is the cold. Because roots normally grow underground where they are well protected from harsh elements, we don’t think of them as being vulnerable. But in fact it is the roots of a plant that are the most tender, and when there is only an inch of terra-cotta between them and a bout of 10-degree days, there could be trouble.
There’s strength in numbers, so the first thing you can do to prevent damage to plants in pots is to group the containers together—preferably up against the house, under a patio awning, or under the deck.
Plants such as hostas can be cut straight through. Hostas are good candidates for dividing, although you may need to take a saw to cut the pieces apart.
Plants that increase by growing new rosettes of foliage next to the mother plant, such as thrift (Armeria), can be separated. It might be easier to dig up the whole plant to separate them; pull apart and cut connecting roots.
Plants that expand by stolons—underground stems—such as Phlox paniculata can be dug up in sections, slicing through the root system as you go.
Winter is pretty much vacation time for the gardener, especially when it comes to perennials. Those that keep any sign of life aboveground (such as a rosette) can take care of themselves.
Autumn cleanup can now be considered winter cleanup. Cut back dead foliage and stems. A good rationale for waiting until late winter to do this is because the dead leaves and stems offer some protection to the crown of the plant from excessive water and cold.
Winter is a good time to plan for summer dryness. Snake a soaker hose through the areas of the garden where you have grouped those plants that need supplemental water during dry weeks. Or rearrange the soaker hose that you have, if you have shifted the perennials in your garden around. If you don’t do it now, you won’t get it done.
During mild weather, dig, divide, and pot up extra plants to give away or donate to a spring plant sale.
Wait for the first flower. You won’t have to wait long, as the hellebores will already be peeking out of the ground.
The easy answer to the question, “When is a good time to mulch?” is: “Whenever you have the time.” Many of our garden tasks get done when we have a chance to do them, regardless of advice, calendars, and what the neighbors are doing. That’s life.
Fortunately, a good time to put mulch down is in the quiet garden season—winter. In winter, the mulch can be piled up a few inches on top of dormant perennials with no harm done. In winter, the soil is moist, so you’re already planning for the dry days ahead by laying a protective blanket. Throughout the rest of the rainy season, the top layer of soil doesn’t get beaten down so that it forms a crust when dried out. Drenching rains don’t waterlog soil beneath, because the mulch slows the flow of water by trapping drops within its maze of various-sized particles. The seeds of winter weeds get covered up and so don’t have light to germinate.
But what if somehow winter got away from you without the mulch being spread? The world is not going to come to an end. Spring is a fine time to mulch the garden, although you do need to be a little more careful about those emerging plants.
Actually, almost anytime is a good time to mulch. The only part of the year you want to avoid is full summer, when the soil is bone dry. You don’t want to protect dry soil, and you don’t want to be out there on a hot August day shoveling manure, do you?
Nectaroscordum siculum
