Here in northwestern Connecticut, the fall foliage show is nearing its peak, and in some places, the leaves have begun to fall. They rustle at our feet as we go about our rounds. This is Nature’s way of telling us it’s time to clean the garden.

Clearing out beds and borders means different things to different people. Some gardeners clear every last leaf and past-bloom plant from their gardens while others find reasons to leave everything as is until spring. We fall somewhere in the middle. We believe that maintaining a healthy garden and nutritious, well-structured soil requires different cleanup rituals for different garden spaces. At the farm, here’s how we go about it:

Remove Most Annuals

For starters, we remove most annuals. In general, these plants are easy to spot because after the first hard frost, many of them, including impatiens, begonias, and coleus, have withered and turned brown. If the spent foliage and blossoms on these plants are free of mold and disease, we put them in the compost pile. If we see traces of powdery mildew (zinnias are often afflicted), downy mildew or other diseases, the plants are put into trash that’s hauled off the property. Keep in mind that any mold or disease that’s allowed to stay in the garden will overwinter and reinfect new growth in spring.

Some annuals argue to be removed a bit later in the fall. “If the Cosmos or verbena bonariensis are still green and self-sowing, I will leave them until later,” says nursery manager Barb Pierson. “Plants like Rudbeckia ‘Prairie Sun,’ which can overwinter here, will be left until spring. Kale is pretty late in the season, too.”

Clean Out the Vegetable Garden

In the kitchen garden, Pierson removes all vegetable plants, paying special attention to any varieties, such as tomatoes, that may have fungal leaf spots and mildew. Afflicted plants must be completely removed and put into the garbage (or carted to the dump) or the same afflictions will plague next season’s plants. “Most vegetable plants are best removed unless you are growing fall lettuce or other cold crops here in New England,” Pierson says. “If we plan to plant tulips in the raised beds for a nice spring show, this is the time to do it. If we don’t plant bulbs, we will remove any soil that comes up with the vegetables and add fresh soil in spring. Compost can be added in the fall if it is fresh, but we prefer to do it in the spring because we use fully composted material. Each spring, we replace the top 1/3 of soil – at the least – for best results. Mulching can attract digging rodents so we don’t mulch the beds during the winter months.”

Perennials & Shrubs

In the perennial garden, our methods vary. In the shady beds near the store, our gardeners clean and clear away dead and dying foliage. They cut back ferns, hostas, astilbes, and ligularias. Why? One year, when they let the decaying leaves lie, they discovered that the cushy, warm environment attracted critters who dug around and sometimes nested in the leaf mulch. That would have been all right except the critters didn’t stop at the mulch. They burrowed into the roots of the plants, inadvertently killing a few, and those had to be replaced the following spring.

In areas where critters don’t pose much of a problem, Pierson and many others believe that the decaying leaves of most deciduous trees are beneficial to the garden. For starters, they form a natural leaf mulch that provides insulation for perennials and shrubs. Oak leaves, which are waxy and don’t easily break down, are particularly good for insulation. Mounding them around perennials and shrubs protects the plants from seasonal temperature swings. Pine needles are another fine insulator, and they’re especially good for acid-loving plants including rhododendrons and azaleas. Leaves that break down more readily such as maple, ash and birch leaves add organic nutrients to the soil, and help improve soil structure.

As with annuals and vegetable plants, it’s important to note that any perennials or shrubs that exhibit mold or disease should be cut back, and the spent foliage and blossoms should be carted away to the trash (not the compost pile). Plants like Perovskia (Russian Sage) should not be cut to the ground, Pierson says. “The most important thing to remove is the foliage – not the crown or stems – so I would say remove leaf litter and prune stems as you would for that variety, in general 3-4” above soil level.” Some of the perennials and shrubs most commonly affected by powdery mildew include peonies, monarda (bee balm), phlox, and roses. As with vegetable plants and annuals, if you leave afflicted plants in the garden, the mold and disease will overwinter and reassert itself in spring. The mold won’t interfere with blossom production, but it will detract from the beauty of the foliage.

As you cut down bee balms, phlox and peonies, keep in mind that there are other perennials and shrubs you’ll want to keep. While ornamental grasses can be cut back in fall (leaving 6” of growth to protect the crowns), the argument for leaving them until spring is that they look quite lovely dusted in snow. The seed heads of Echinacea and the berries of Ilex verticillata (winterberry) feed the birds as winter sets in. The pods of Asclepias, the flower clusters of Sedum ‘Autumn Joy’ and Eupatorium, and the seed heads of Echinaceas (Coneflowers) all provide winter interest.

So clean as much or as little as you choose depending on the types of plants you have in your garden. But whatever you decide, it’s time to grab your rake and pruners, and spend a few days in the glorious autumn weather putting your garden to bed.

It’s no secret to any gardener based in New England that the region is experiencing a significant rainfall deficit. In Connecticut, where we’re located, assessments provided by NOAA, the National Oceanic and Atmospheric Administration, for September 2016, indicate that all regions of the state are in either “extreme drought” (a deficit of 2.75” of rain or greater) or “severe drought” (a deficit of 2” to 2.74” of rain). While October delivered a few showers, we still have a lot of making up to do. The situation is the same across New England. (See for yourself by clicking here.)

In September, according to NOAA, “Abnormally dry and drought conditions continued to contract in the Midwest and intensify in the Northeast, where extreme drought developed. The unusually warmer-than-normal temperatures increased evaporative stress which exacerbated the drought conditions in the Northeast. Soils were dry, vegetation stressed, and groundwater and streamflow levels low. According to USDA statistics, topsoil moisture was short or very short (dry or very dry) in 50 percent or more of Rhode Island (100%), Massachusetts (78%), Connecticut (76%), New Hampshire (65%), and Vermont (53%); subsoil moisture was short or very short in 50 percent or more of Rhode Island (100%), Massachusetts (91%), Connecticut (80%), New Hampshire (63%), and Vermont (52%); and pasture and rangeland was in poor to very poor condition in 50 percent or more of Massachusetts (81%), New Hampshire (65%), Rhode Island (60%), Maine (59%), and Connecticut (56%).”

Massachusetts and Connecticut have been critically impacted, according to the NOAA data. “Fifteen states ranked in the driest third of the historical record for April-September, with two in the Northeast having the tenth driest, or drier, such 3-month period. These were . . . Massachusetts (at fourth driest) and Connecticut (at fifth driest). The last three April-September time periods have been drier than average for these two states.”

In southern New England, the dryness is part of a longer-term pattern. “Thirteen states ranked in the driest third of the historical record, with the severest dryness (driest ranks) persisting in southern New England — Connecticut had the fifth driest January-September and Massachusetts the seventh driest,” according to NOAA. “Four of the last five year-to-dates have been much drier than average for Connecticut.”

In forecasting trends for this winter’s weather, NOAA predicts New England’s drought conditions may improve somewhat in western parts of the region but dry conditions may persist in the east.

What does all of this mean for gardeners? Water. Water. Water. Unless restrictions have been imposed in your area, continue to water your gardens and any new plantings including trees and shrubs until the ground freezes hard. Plants that have been stressed by lack of water are far more vulnerable to winter kill. New plantings are at particular risk. Keep your plants hydrated by watering on a weekly basis. (Ideally, you want to water slowly – setting up a sprinkler or drip irrigation system are two ways to do it. The goal is a slow but steady discharge of water that will seep down to the roots of your plants. You want to stop watering before the ground is too saturated to absorb more. Do not overwater or plants will be discouraged from forming good root systems. Standing water might also freeze overnight creating a hazard for you and your plants.)

The ground here in Litchfield County generally freezes hard sometime after Thanksgiving so we’ll keep watering until then.

Watering Guidelines for New Plants

For best results with new plants including potted perennials, shrubs, trees and vines, give their roots a good soaking in their pots on the day before planting. (You may even stand each pot in a bucket of water for up to 30 minutes so the soil is soaked through. Remove each pot from the bucket and let it drain.) On the day you put the new plants in the ground, water them again, as needed, before and after planting.

For bareroot perennial specimens, soak the roots in water for a few hours before planting. If the root is woody (as in roses), soak for up to 12 hours. Follow directions for planting your bareroot specimen then water it in once planted.

Water Restrictions

If you live in an area where water restrictions have been imposed, you may choose to collect “grey water,” the type that’s generated by routine household rituals including bathing, brushing your teeth, washing dishes, and rinsing fruits and vegetables. As you start the shower or run the tap to rinse something or wait for hot water, collect the runoff in buckets or jars and bring it outside. Please note: While grey water that contains detergents or soaps may be used for some things, it is not recommended for watering plants. Be sure your grey water is free of shampoo, soap, toothpaste, dish detergent, grease, etc., which can potentially damage your plants or attract critters.

Rainfall, if we get much, is another excellent source of water. Install rain barrels below your gutter pipes or set out buckets and pails to catch whatever falls from the sky. This is a terrific practice whether or not drought conditions prevail.

Take Care of Your Hose

To prevent your hose from cracking on nights when the temperature dips below freezing, remember to discharge any water that’s trapped in it after each use.

While many of you undoubtedly spent summer engrossed in the latest New York Times bestselling beach reads, around here, the books we can’t put down are Weeds of the Northeast by Richard H. Uva, Joseph C. Neal and Joseph M. DiTomaso, and Weeds of North America by Richard Dickinson and France Royer.

Both are indispensable guides to the pesky weeds that gardeners in North America regularly come upon in beds, borders, meadows and woodlands. Weeds of the Northeast was published in 1997 by Cornell University Press. At nearly 400 pages, it offers color photos of 299 weeds at various stages of their lifecycles – starting at the seedling stage. Weeds of North America was published in 2014 by the University of Chicago Press. It covers roughly 500 species of weeds, and includes color photos showing the majority of them at stages from seed to flower. (Interestingly, it also lists plant viruses that each weed could introduce into your garden and which may be harmful to other plants.)

As we continue to pull weeds from our gardens, we thought you might like a primer on 10 of the most common types that might be appearing in yours.

Common Pokeweed (Phytolacca Americana L.)

You can tell a lot by a nickname, and this one is commonly known as Inkberry (for its dark reddish-purple berries), Red Ink Berry (for the color that’s released when the berries are crushed), and American Cancer (for the toxicity of the leaves and fruits). The one thing Pokeweed is not is a poke. The herbaceous perennial emerges in spring and, left untended, achieves the height of a small tree. It will climb over shrubs and grow alongside trees. You’ll recognize the seedlings by their oval green leaves, which often have a hint of reddish purple. As they begin to stretch, you’ll see that the stems are also a reddish-purple. Green berries emerge in clusters, gradually changing to a gleaming purple-black. The shape of the berries is distinctive, too, like round balls that have been slightly flattened on each side. Large taproots make these a contest to remove, but it’s worth winning.

Canadian Clearweed (Pilea pumila)

This summer annual has watery, almost translucent stems that remind us of Impatiens. The fresh, shiny green leaves are opposite and have three pronounced central veins and  serrated edges. The small flowers emerge from leaf axils and appear in clusters on the upper portions of the stems. Pull this weed, and it gives way very easily, which may account for our benign feelings about it.

Black Swallowwort Vine (Cynanchum nigra)

The bane of many a northeastern gardener, this twining, vining perennial can twist itself around shrubs and small trees. It has dark green leaves, purple-black fruit, and, most unhappily, a large root crown, which makes removal an Olympic sport.

“Although primarily a woodland species, black swallowwort has become an invasive weed in recently cleared areas, conservation habitats, Christmas tree plantations, nursery crops, and other perennial crops such as alfafa. It also grows in fields, pastures, and waste places and along fence rows, often in sunny areas and calcareous soils,” write Uva, Neal, and DiTomaso. In short, it can be everywhere. Our recommendation: Dig it out to be certain you’re getting it by the roots, or you’ll be seeing it in perpetuity.

Bull thistle (Cirsium vulgare)

Sometimes confused with Canada thistle, this biennial is distinguished by its leaves, which are spiny above and woolly below (Canada thistle leaves are the opposite: smooth above and smooth or spiny below), and by its taproot (Canada thistle spreads by rhizomes.) Bull thistle favors rich, moist soil. It presents in spring as a rosette of leaves that are prostrate to the ground then develops a stem, which is punctuated by lance-shaped, serrated leaves. Bulbous lavender-purple fruit appears at the tops of stems.

Canada thistle (Cirsium arvense)

This perennial is hard to miss, especially if you’ve had the misfortune to step on it or come upon it ungloved. The spiny leaves appear first as a prostrate basal rosette and gradually lengthen. Allowed to mature, the Canada thistle will sprout stems topped by lavender-purple flower heads that open to release seeds that scatter in the wind. Where there is one, you may expect many more as Canada thistle spreads by rhizomes.

Crabgrass (Digitaria sanguinalis, Digitaria ischaemu Schreb. ex. Muhl, DIGIS, and Digitaria ciliaris (Retz.) Koel, DIGSP)

This one needs no introduction. There are three common varieties, Large crabgrass (Digitaria sanguinalis), Smooth crabgrass (Digitaria ischaemum Schreb. ex. Muhl, DIGIS), and Southern crabgrass (Digitaria ciliaris (Retz.) Koel, DIGSP). All are the bane of gardeners everywhere. The blade-shaped green leaves emerge along prostrate stems. The fibrous roots always seem to be rooted in cement because they’re just that difficult to pull out. The part of the plant that’s above-ground seems always to snap off in your hand before the roots can be dislodged so use a weeding tool to loosen the soil then pull.

Creeping Charlie (Glechoma hederacea L.)

Also known as Ground Ivy, this is not an ugly weed, it’s just a perpetual land-grabber. It creeps along the ground by runners, each node setting down new roots as the spreading continues. It’s especially fond of vaulting the distance between lawns and garden beds, and it will even crawl across the patio, if it can find sufficient footing. The round, scalloped green leaves form a mat-like ground cover, and in spring, purple flowers appear. Grab a string (or six) of stems and give them a tug. You’ll feel individual nodes pop out of the soil. A firmer tug releases the developed fibrous roots at the base of the plant.

Broadleaf Plantain (Plantago major L.)

We feel a special animosity toward this one, a prostrate grower that holds tenaciously to the soil with a cluster of fibrous roots and single taproot. The broad green, deeply veined leaves hew to the ground, forming a mat from which sprout green flower heads that later turn golden brown.

Bishop’s Weed (Aegopodium podagraria)

The variegated form of this super-spreader is called Goutweed. It’s offered at many nurseries as a ground cover, and while quite ornamental, it quickly manifests as a nuisance. To quote the Missouri Botanical Garden’s outstanding website, It “Will rapidly form a continuous mound of attractive foliage typically growing to 8″ tall with an indefinite spread. Unfortunately, once it gets going, it acts like the proverbial snowball going downhill and can be difficult to contain.” While it is easy to remove with a quick tug, you may find the constancy of the job gets tiresome quickly.

Garlic Mustard (Alliaria petiolata)

This European native was originally introduced to North America in the 1800s and was valued for its medicinal and culinary properties. But since then, this shade-tolerant biennial has become too common in wooded areas of the eastern and middle of the United States where it crowds out natives. Now regarded as an invasive, it forms basal rosettes of heart-shaped leaves in the first year. The following season, the leaves become more triangular in shape, and the plant sends up a 1–4’ stalk that produces small white flowers in early spring. Apart from identifying the plant by its appearance, you can crush a leaf or stem. If you smell garlic, remove the plant.

Common Lambsquarters (Chenopodium album L.)

We find this upright annual in lots of places at the farm where it likes to pop up at the edges of fields and meadows. The gray, felted-looking leaves make it easy to spot along with its broad, branching habit. Left to grow, it can reach heights of 3’ in a single season.

 

With summer heat baking much of the nation, it’s a good time to review some of the basics of watering. Our horticultural advisors have lately received a number of contacts about issues pertaining to plants that are being either under-watered or over-watered.

Cathy Hughes, Senior Horticulturist for the Customer Service Call Center, says, “I just had a phone call that perfectly illustrates the concern. The customer lives in Queens, N.Y., and she wanted to know why the leaves on her ‘Patriot’ hostas turn brown every summer. I asked how long they’ve been established, and how often they get watered. She said they were planted three years ago, and are watered with an automatic sprinkler system every morning and evening for 15 minutes each time.”

Automatic sprinkler or irrigation systems are a convenience for many gardeners, but they need to be properly programmed and adjusted for weather conditions. We’ve all seen sprinkler systems running after (and even during) a deluge. Auto irrigation systems also are generally the culprit when watering is being done in 15-minute intervals.

A better method is to water plants less frequently but more deeply. You want the soil to dry out between waterings because that’s what encourages healthy root systems. “Shallow watering, the kind you get when you turn on the hose or irrigation system for 15 minutes, promotes shallow root systems because plants don’t have to go looking for water,” Cathy says. “The water problem is exacerbated if the soil is mulched because the mulch facilitates water retention.”

As a general rule of thumb for established perennials, Cathy advises “watering when the soil is dry to a depth of 2”, and always checking the soil before watering because hot weather does not necessarily mean the soil is drying out, especially if conditions are humid.” In addition, plants may wilt as a response to high temperatures, but the soil may still be moist. If the plant recovers either late in the day or early in the morning, and you have not watered, this is a clear indication that the soil is still moist.

The best way to check the soil is to stick your finger in the dirt, or push a spade in and remove a clot of earth to see how deep the dryness goes.

Gardeners should keep in mind that different plants have different watering needs. Annuals, which are planted in spring and give their all in one season, generally need more water than perennials that have many seasons to develop root systems; plants situated in full sun almost always need more water than those in shade; plants that live beneath large trees, where they’re forced to compete against tree roots for water, will need more hydration support than most; and new plantings will require more regular watering than established plants.

Container pots are a different story. They tend to dry out quickly, especially if pots are made of porous materials such as terra cotta. Most pots, unless they’re filled with succulents and other drought-tolerant plants, will need to be checked daily especially in the heat of summer.

For tips on proper watering of your vegetable garden, see our June 14, 2016 blog post “Caring for Your Vegetable Plants.”