Notes on Annuals, Perennials, Plant Naming, and Site Planning

Transition from Annuals to Perennials and Naming Practices

• The instructor references a list of plants “highlighted in yellow” as the student’s responsibility. Some of the annuals will be removed from the list; only the ones still looking stellar may remain, and some may continue to be challenged or pushed later.
• Plan to transition the class focus from annuals to perennials; reminder to revisit this tomorrow.
• There is a tab labeled handouts with a document titled “annual seed sources.” This document lists several companies that sell seeds, plugs, or both, including some that sell annuals, perennials, and other plant types. Not all sellers show up on the list; there is more available out there.
• Example plant discussed: Celosia argentia plumosa (plume type Celosia). Celosia can be listed as Celosia plumosa or Celosia nerstata, with plumosa often treated as a group or a variety depending on taxonomy; the instructor emphasizes calling plants by species rather than cultivars to avoid confusion.
• Important naming distinction: annuals (often communicated with common names in consumer settings) vs perennials/woody plants (often communicated with botanical names). Homeowners typically recognize common names; wholesalers and professionals prefer botanical names for precision.
• Wholesale communications typically use botanical names; garden centers serving homeowners may rely more on common names, but professionals in wholesale channels emphasize higher-level botanical terminology.
• The class accesses a perennial grower’s site (in Southeastern PA near Huntsville). The wholesale availability list shows plants currently available; the list emphasizes botanical names only (no common names on the page) to avoid confusion.
• The class highlights Coreopsis lanceolata as an example of a straight species (no cultivar listed on the wholesale sheet). Straight species are the genus and species without a cultivar designation; cultivars are selected forms with specific traits.
• The term to remember: straight species vs cultivar. Students are told to write down and memorize this distinction; it’s repeatedly used when native plant enthusiasts discuss planting strategies.
• Native plants are emphasized as important; many people prefer native, seed-grown varieties over cultivars because seed-grown plants retain more genetic diversity.
• The plant list from the AQPAC catalog is used as a reference. AQPAC sells both finished plants and plugs; the catalog shows many herbaceous plants including perennials and annuals. Examples from AQPAC include:
  • Slosea (plume-type Celosia) and Cosmos (Kosmos) with several varieties indicated by abbreviations.
  • Dusty Miller (Senecio cineraria) and Proscena spikes.
  • Flowering cabbage and flowering kale ( Brassica oleracea ) – discussion of how the same species can yield different edible or ornamental forms depending on the cultivar.
  • Nasturtium (Tropaeolum majus) appears in the catalog and is referenced as a seed-grown annual.
  • Barovskia (likely Barvskia, now Perovskia) introduced to students; the instructor notes that many people still use the old name and may not recognize the updated taxonomy.
  • Brassica oleracea as a single species that includes kale, cabbage, broccoli, cauliflower, Brussels sprouts, etc.; the different edible parts are determined by the cultivar rather than the species.
• The catalog also lists ornamental grasses (e.g., Panicum millet) with cultivar names such as “Purple Majesty.” The edible/ornamental line is blurred in some markets (millet vs panicum vs other grasses).
• The discussion covers several annuals and perennials that students may recognize from other sources: Coneflowers (Echinacea), butterfly weed, Achillea (yarrow), etc., emphasizing the need to know botanical names for professional communication.
• The instructor notes that there are many new varieties and trends in both annuals and perennials, including new star-shaped “star fan” flowers and other innovative forms. These updates are challenging to keep up with, and some brands (e.g., Proven Winners) curate container-focused inspiration rather than listing every single cultivar.
• Proven Winners overview:
  • They are a major brand in the market, offering thousands of plant collections.
  • The brand provides tools such as container garden recipes and top-picks to help design lovers assemble attractive plant combinations.
  • Container garden recipes may not perfectly match every available cultivar regionally, but they provide solid guidance for similar aesthetics.
• The instructor recounts a story about a grower tour (Quali Perennials, near Harrisburg, in the Dillsburg area) to illustrate color selection and color sense in container plantings. A male employee was criticized for color choices compared to a more color-aware former female employee; the takeaway emphasizes color theory and the importance of having an eye for color in container design.
• The marketing and naming complexity: new varieties arrive frequently, and the trade names (e.g., Supertunias, Supertunella/ Supertunias, Superbells) reflect branding and cultivars; growers often release new lines under trade names to simplify marketing while signaling performance traits.
• Seating and labeling challenges: some labels may use ornamental group names (e.g., Euphorbia “Star” series) rather than traditional common names, which can be confusing for students used to common names. The instructor uses examples like a star-shaped Euphorbia that lacks the traditional fan-like shape, illustrating how plant morphology can be misread if the label isn’t precise.
• The session acknowledges that many people will still refer to plants by old or alternative names (e.g., Barovskia vs Perovskia; Poroskia), so while updated taxonomy is introduced, you should anticipate continued use of older names in conversation and market materials.
• The value of staying current: new plants and naming conventions appear continuously; whether a student likes annuals, perennials, or woody plants, you must stay informed about the latest cultivars, branding, and availability to avoid being left behind.
• Plant categories and terminology for landscape design:
  • Uses: privacy or screening, windbreaks, directional or traffic control, foundation plantings, mass plantings.
  • Accents and specimens: accents or fillers, specimens (thrillers) for focal points; thrillers attract attention, fillers fill space, and spillers trail.
  • Aesthetic goals: accent plants draw attention; specimens serve as focal points; the combination creates a dynamic landscape.
• Practical landscape design discussions:
  • Screening and privacy: a block or varied-opacity screen can be used; not all screens must be completely opaque; some can be semi-transparent (e.g., certain grasses like Miscanthus).
  • Deciduous vs evergreen considerations: deciduous trees can shade in summer but allow light in winter when they lose leaves.
  • Seasonal variation: screens and plant materials can be seasonal and are not required to be evergreen.
  • Wind breaks: understand winter wind directions to plan which trees or evergreens provide relief.
  • Backgrounds and borders: candle lilies, dahlias may appear in borders; staff note that some container beds also feature dahlias and other bold additions.
  • Directional planting: plants can guide viewer movement visually (e.g., hedges or repeated plant cues marking a path).
  • Example of guiding movement: in a front area near the visitor center, a pathway exists where people previously walked through a bed. Instead of fighting this, a dedicated path with a protective structure beneath the surface was installed to reduce mud and wear. The talk mentions a subsurface structural system that helps prevent mud from forming in winter due to heavy foot traffic.
• Site environment considerations for perennials and woody plants:
  • Moisture availability: some plants prefer drier soils, others more moisture; mixing plants with contrasting moisture needs can be challenging and may require drainage and soil amendment strategies.
  • Aeration and drainage: good soil aeration and drainage are essential for healthy roots; compact or heavy soils require careful management.
  • Soil pH and fertility: understanding soil fertility and pH is crucial; lean soils may support plants that don’t require heavy nutrients; heavy organic soils can overwhelm plants that need lean soils.
  • Soil texture and structure: texture (sand, silt, clay) and structure affect water retention, drainage, and root growth; soil texture influences how much moisture and nutrients are available to plants.
• Moisture management example:
  • A dry-loving plant in a container may become stressed if overwatered; one plant in a bed looked terrible due to too much moisture; moisture management is key for herbaceous perennials and woody plants in containers.
• Site orientation and sun exposure definitions:
  • Full sun: at least $6$ hours of direct sunlight per day.
  • Part sun: roughly $4-6$ hours of sunlight, direct or indirect.
  • The sun path and its seasonal variation matter: in summer, the sun is high and intense; in winter, the sun is lower and shadows are longer.
  • Sunrise direction: rises in the East; sunset direction: West. Morning sun is typically on the eastern exposure; late-day sun is from the southern to western exposure depending on season.
  • North-facing exposures tend to be cooler and more shaded; the west generally experiences more wind and sun intensity in the afternoon.
  • Design considerations: north orientation in design planning; the front of a house is typically south-facing for maximum sunlight; students should interpret sun paths with seasonality in mind.
  • Real-world orientation reminders: North, South, East, West can be confusing without a mental model of the sun’s motion; examples and mnemonics (sun rises in the East; highest in the South; sets in the West) help anchor understanding.
• Practical teaching examples related to orientation and design:
  • Students may rely on a compass on a watch or phone, but real-world project sites often require estimation when weather conditions (cloud cover) obscure the sun.
  • Google Earth/Street View can help analyze an existing property, but new developments may not be represented in real time; you may encounter discrepancies between map data and the current site.
  • When a site has tricky geometry or obstructed sun, it’s essential to observe actual light conditions across all seasons before finalizing plant placements.
• Planting design principles in practice:
  • Understand the growth habits and morphology to avoid misreading labels (e.g., a star leaf or fan-shaped foliage may indicate a different genus or cultivar than expected).
  • Expect updates in plant branding (e.g., trade names and branding groups such as Supertunias/Superbells) that influence consumer recognition, even if the underlying species hasn’t changed.
  • The landscape design process includes selecting plants for texture, color, and form, while balancing maintenance needs and seasonal interest.
• Perennials and future plans:
  • Tomorrow’s class will continue with perennials; more interactive labs are planned, such as choosing a location for plants and deeper discussions of environmental conditions relevant to perennials and woody plants.
  • Emphasis on site selection and proper placement to maximize long-term success and minimize wasted effort and resources.
• Quick recap of key terms to remember:
  • Straight species: the genus and species without a cultivar designation; used by native plant enthusiasts and in professional settings for seed-grown diversity.
  • Cultivar: a cultivated variety with selected traits; often used in ornamental plantings for uniformity and branding.
  • Accents, thrillers, fillers, spillers: typologies in landscape design describing plant roles (thrillers = focal, specimens; fillers = mid-layer; spilers = trailing plants).
  • Privacy/screening, windbreaks, directional/traffic control, foundation plantings, mass plantings: common landscape design purposes for plant selection and arrangement.
  • AAS winner and All-America Selections (Nasturtiums, Marigolds, etc.): performance awards for plant varieties relevant to gardeners and professionals.
  • Perennial availability and native emphasis: ongoing priority in professional horticulture, with a preference for seed-grown native varieties for genetic diversity and ecological fit.
• Notable plant examples mentioned (for familiarity, not exhaustive):
  • Coreopsis lanceolata (straight species; container demonstration referenced).
  • Echinacea (coneflower) and Echinacea species; other natives discussed in relation to plant lists.
  • Butterfly weed, Achillea (yarrow), Delphinium (Kosmos abbreviations in catalogs), Cosmos, Dusty Miller, Proscena spikes, Nasturtium, Barovskia (Perovskia), Panicum millet (Purple Majesty cultivar), and misreadings or renaming issues (e.g., Barovskia vs Perovskia).
  • Flowering cabbage and flowering kale in ornamental contexts (Brassica oleracea); discussion of how same species can yield different ornamental or edible results based on cultivar.
  • Star-shaped star-fan flowers (new trends) and other newly introduced forms that require ongoing learning.
• Tomorrow’s focus and anticipated topics:
  • Perennial-focused content, including more interactive labs and exercises.
  • Deeper exploration of site selection and environmental planning for perennials and woody plants, with emphasis on long-term success and maintenance.
  • Continued discussion of plant naming conventions, naming updates, and practical communication strategies for professional and homeowner audiences.