Evaluating Perennials for Chicagoland Gardens

Perennials in Focus is a plant evaluation program that examines new and underused plants for Chicagoland, the third largest metropolitan area in the country. A group of horticultural experts trials and evaluates plants at numerous locations across the region. Results help consumers, public gardens, growers, landscape designers, breeders, and other industry professionals make informed plant choices.

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Winter perennials for chickadee and titmouse nesting material

A winter garden can serve birds long after its flowers have faded. Perennial stems, dried leaves, seed fluff, bark fibers, and soft plant debris remain available through the cold season, creating useful habitat for small birds preparing for spring nesting. In the Chicagoland region, where late snow and freezing temperatures can continue well into March, these structures may be more valuable than a perfectly cleared garden.

Black-capped Chickadees and Tufted Titmice usually nest in tree cavities, abandoned woodpecker holes, nest boxes, or other sheltered openings. They do not build large woven nests in shrubs, yet they still need a lining of soft and insulating material. Chickadees commonly gather moss, plant fibers, fur, hair, and feathers, while titmice may use leaves, bark strips, grass, and animal hair.

Choosing perennials with useful winter structure supports this seasonal behavior without turning the landscape into an untidy collection of dead plants. It also benefits insects, seed-eating birds, and overwintering wildlife. The best choices combine durable stems with regional garden performance, attractive form, and a place in a low-disturbance planting plan.

Why winter structure matters for cavity nesters

Chickadees and titmice begin searching for nest sites and supplies before most perennial gardens show fresh growth. That timing makes standing vegetation important. A clump of dried grass, a persistent seed head, or a fibrous stem can remain accessible when the soil is frozen and new leaves have not yet emerged.

Plants do not need to produce a specific “nesting fiber” to be useful. Birds may pull apart old leaves, break small sections of dry stems, or collect down from seed heads. Some materials are gathered directly from plants, while others accumulate around their base and become available as birds forage through leaf litter.

Leaving vegetation standing also protects the insects that support chickadees and titmice during winter and early spring. Small birds often inspect stems and leaf clusters for dormant insects, eggs, and larvae. A garden managed for both nesting supplies and prey will generally provide greater value than one cut to the ground in autumn.

Perennials with useful fibers and stems

Ornamental grasses are among the most dependable sources of winter structure. Little bluestem, prairie dropseed, switchgrass, and other regionally hardy grasses hold narrow leaves and flower stalks above snow for months. Birds may use pieces of dried foliage, while the dense clumps provide cover as they search for food.

Many native forbs contribute through persistent stems and seed coverings. Culver’s root, goldenrod, asters, coneflowers, bee balm, rattlesnake master, and milkweed can retain useful material into winter. Milkweed is especially recognizable for its silky seed floss, though birds may use only small amounts of it and its primary wildlife value also includes supporting specialist insects.

Sedges and other fine-textured plants can add softer material near the ground. Fern fronds, heuchera leaves, hellebore foliage, and broad perennial leaves may break down into nest-lining material over time. Gardeners should avoid treating every brown leaf as a problem; some dry plant matter is precisely what makes a winter planting functional.

Matching plant choices to regional performance

A plant that supplies potential nesting material still needs to survive and perform reliably in local conditions. Chicagoland gardens vary widely in soil moisture, wind exposure, shade, and winter salt. A drought-tolerant prairie plant may struggle in a damp woodland border, while a shade perennial may collapse in an exposed boulevard bed.

Regional evaluation helps gardeners compare practical traits such as mature height, spread, flowering period, foliage persistence, and seasonal habit. The Perennials in Focus program is especially relevant because its collaborative trials examine how perennial plants perform across Chicagoland gardens and seasons. Those observations can help identify plants that offer both habitat value and dependable landscape performance.

Phenology also matters. Early-emerging plants can provide fresh cover before taller perennials regain their height, while late-season species may preserve structure through the coldest months. Gardeners can review early spring foliage comparisons when selecting low-growing plants for woodland edges and shaded areas where winter appearance and spring transition are both important.

Comparing useful winter plant structures

The following groups are practical starting points rather than a definitive ranking. Availability of nesting material depends on the plant’s growth habit, winter weather, local bird activity, and how much of the planting is left undisturbed.

Perennial group Winter material or feature Suitable garden conditions Maintenance approach
Little bluestem and prairie dropseed Fine dried leaves and persistent seed stems Sunny, well-drained beds Cut back in late winter
Switchgrass and other upright grasses Long blades, stems, and dense cover Sun to light shade; average soil Leave standing until March or April
Goldenrod and asters Hollow or woody stems, seed heads, insect habitat Sun; average to dry soil Remove only damaged or unsafe stems
Coneflowers and bee balm Persistent stalks and seed heads Sun; average soil Leave seed heads through winter
Milkweed Seed floss and durable stems Sun; well-drained soil Retain some stalks until spring
Sedges Fine leaves and low nesting material Shade to part shade, depending on species Comb or trim selectively
Hellebores and heucheras Evergreen or semi-evergreen foliage near the ground Shade to part shade Remove only winter-damaged leaves
Ferns Dry fronds and sheltered leaf litter Shade; moisture varies by species Cut back in late winter if needed

Combining several forms creates a layered supply. Tall grasses and sturdy forb stems provide elevated structure, while sedges, ferns, and broadleaf perennials offer material near the soil surface. This arrangement also gives birds more cover from weather and predators as they move through the garden.

A mixed planting is preferable to a single mass of one species. If heavy snow flattens one group, other plants may remain upright. Different bloom periods and seed habits also spread habitat value across the year, supporting the broader goals of a resilient perennial border.

Managing the garden for birds

Timing is the simplest management decision. Delay cutting until late winter or early spring, ideally after the most severe weather has passed but before new growth makes cleanup difficult. In many Chicagoland gardens, that may mean pruning in March rather than October. Leave a portion of stems intact each year so the planting retains continuity.

Cut stems at varied heights instead of shearing every plant to the same level. Hollow and pithy stems can shelter insects, while taller stalks remain useful as perches and visual cover. Place removed stems loosely in a corner of the garden rather than sending all material away; birds may still collect fibers from a brush pile.

Avoid pesticide use where possible, especially broad-spectrum applications that reduce the insects birds need to feed their young. Do not put out dryer lint, synthetic fibers, string, or pet fur treated with flea medications. Natural plant fibers, clean animal hair from untreated sources, and naturally shed feathers are safer options when supplemental material is offered.

Planting and maintenance choices that help

A bird-supportive perennial garden does not need to look neglected. Clear paths, patios, and sightlines while allowing selected habitat zones to retain stems and leaf litter.

  • Combine upright grasses, persistent seed heads, and low sedges for varied nesting resources.
  • Keep at least part of each planting standing through winter and early spring.
  • Choose plants suited to the site’s light, drainage, soil, and salt exposure.
  • Group several perennial species so one weather event does not remove all winter structure.
  • Avoid synthetic nesting fibers and pesticide-treated materials around bird habitat.

Place these plantings near mature trees, shrubs, or nest boxes rather than in an isolated open bed. Chickadees and titmice need safe travel routes, cover, and reliable insect habitat as well as nest-lining materials. A layered edge between canopy and perennial border can connect all of those resources.

Small maintenance changes can have a large seasonal effect. Leaving coneflower heads intact, postponing grass trimming, or allowing a few fallen leaves to remain beneath a sedge clump gives birds access to natural materials that would otherwise disappear during autumn cleanup.

A Chicagoland garden planted with durable grasses, fibrous forbs, sedges, and persistent foliage can support chickadees and titmice while retaining strong ornamental character. Explore regional perennial trial findings, record which plants hold their structure in your own garden, and make winter habitat part of the planting design rather than an afterthought.

In the Garden

Evaluator gardens are located across the Chicagoland area, representing a range of growing conditions. Visit our retail and wholesale partners to find trialled perennials for your own garden.

Retail & Wholesale: Hinsdale Nurseries (Willowbrook, IL), Mariani Nurseries (Kenosha, WI & Garden Prairie, IL), Northwind Perennials (Burlington, WI), The Growing Place (Aurora, IL).

Wholesale Only: Hinsdale Nurseries (Plano, IL), Intrinsic Perennial Gardens (Hebron, IL).

Our Evaluation Program

The 2017–2020 evaluation cycle included Agastache 'Blue Boa', Allium senescens 'Blue Eddy', Amsonia ciliata var. filifolia 'Georgia Pancake', Astilbe 'Chocolate Shogun', Boltonia astroides 'James Crocket', Brunnera 'Alexander's Great', and Geranium cinereum 'Jolly Jewel Purple'. Completed evaluations include Amsonia 'Blue Ice' (2004–07).

On April 10, 2020, the program published snapshot profiles for Vernonia lettermanii 'Iron Butterfly', Stokesia laevis 'Elf', Stachys officinalis 'Pink Cotton Candy', Lobelia 'Monet Moment', Helleborus 'Winter Thrillers', Geum 'Mai Tai', Geranium soboliferum 'Butterfly Kisses', Gentiana x intermedia 'True Blue', Eurybia divaricata, Asparagus 'Purple Passion', and Agastache 'Bolero'.

Browse the full collection of snapshots organized alphabetically — from A–D, E–H, I–Q, and R–Z — to find detailed performance data on perennials trialled across Chicagoland.

Close-up of drooping orange and yellow spurred flowers with slender petals
Cluster of light purple daisy-like flowers with yellow centers
Tall spike of orange-yellow tubular foxglove flowers against blurred green
Cluster of small tubular orange-red flowers among green leaves