--- title: "Robert Kemp Canna Lily: The Ultimate Growing Guide" canonical: "https://homegardeningblog.com/robert-kemp-canna-lily/" author: "Smith" published: "2026-10-12T15:00:00+00:00" modified: "2026-10-06T17:44:40+00:00" language: "en-US" site: "Home Gardening Blog" description: "Most gardeners looking for the robert kemp canna lily expect a standard broad leafed tropical plant. They end up completely surprised by what actually…" categories: "Garden Care" attribution: "Home Gardening Blog (https://homegardeningblog.com/)" --- # Robert Kemp Canna Lily: The Ultimate Growing Guide Most gardeners looking for the robert kemp canna lily expect a standard broad leafed tropical plant. They end up completely surprised by what actually shows up. This specific variety belongs to the orchid flowered group. It looks nothing like the heavy cannas you see at big box stores. Our research into specialty nurseries shows this cultivar reaches 48 to 72 inches tall. The Royal Horticultural Society classifies these orchid types as tender perennials. You have to treat them differently than standard varieties. Let's break down exactly how to spot them and keep them alive. ## Quick Answer The robert kemp canna lily is an orchid flowered perennial. It features narrow crimson petals instead of broad blooms. Plants grow between four and six feet tall. Rhizomes need winter protection in cold climates. ![robert kemp canna lily](https://homegardeningblog.com/wp-content/uploads/2026/10/robert-kemp-canna-lily-muwyeo27.webp) Image source: Bing (Web (fair-use with source credit)) ## Why the 'Robert Kemp' Canna Lily Looks Nothing Like a Standard Canna Standard cannas belong to the grandiflora group. They produce massive flat flowers and wide paddle shaped leaves. The 'Robert Kemp' canna lily takes a completely different path. It inherits its structure from Canna flaccida, a wild species native to the southeastern United States. That genetic background changes everything visually. Instead of wide petals, you get thin spidery structures. Botanists call these showy parts staminodes rather than true petals. They curl backward slightly and give the flower head an airy texture. This matters when you plan a garden bed. Heavy standard cannas act like solid walls of color. 'Robert Kemp' functions more like a tall see through screen. You can plant things behind it without hiding them completely. Aggregate reviews from landscape designers highlight this architectural benefit. It adds vertical height without creating visual bulk. That specific trait makes it highly sought after for cottage borders. Finding true stock remains the hardest part of growing it. ## Visual Field Guide: Identifying True Orchid-Flowered 'Robert Kemp' Identifying this plant requires close attention to specific physical traits. Generic red cannas flood the market as of 2026. Sellers frequently mislabel them. You need to know exactly what to look for before buying or planting. Here are the primary visual markers we use to verify true stock. | Feature | True 'Robert Kemp' | Standard Red Canna | | --- | --- | --- | | Petal shape | Narrow and elongated | Broad and flat | | Flower size | Small clustered blooms | Large single blooms | | Leaf width | Lance shaped and narrow | Wide and paddle like | | Overall habit | Upright and airy | Bushy and dense | | Color tone | Deep crimson with dark veins | Bright orange red or solid red | ![staminodes](https://homegardeningblog.com/wp-content/uploads/2026/10/staminodes-muwyeoqv.webp) Image source: Bing (Web (fair-use with source credit)) ### What do the staminodes look like? The staminodes on this variety are incredibly distinct. They resemble thin ribbons rather than traditional flower petals. Look closely at the bloom clusters. Each individual flower should feature crinkled edges that twist slightly outward. If the flower looks perfectly flat and round, you have the wrong plant. True orchid flowered types always look slightly messy. That untidy appearance is their main selling point. It mimics the look of wild tropical species. ### How does the foliage differ from other cannas? Foliage provides your second major clue. Standard cannas push out leaves that easily span six inches across. 'Robert Kemp' keeps its leaves much tighter. Expect lance shaped blades that stay relatively narrow compared to the stem height. The green color tends to run darker too. It lacks the bronze or purple tinting found on many modern hybrids. When you combine the narrow green leaves with those spidery red blooms, the identification becomes clear. Always check both the leaf shape and the flower structure together. ## Growing Specs and Site Requirements for Spidery Cannas Getting this plant to bloom requires matching its native preferences. It grows vigorously once conditions align. Get the soil or light wrong, and you will end up with tall green stalks and zero flowers. These plants demand full sun. We are talking about a minimum of six hours of direct light daily. Eight hours produces significantly better bloom density. Shade causes the already tall stems to stretch and flop over. Soil drainage sits right next to sunlight in importance. Canna rhizomes store massive amounts of water and starch. If they sit in heavy clay that stays soggy, they rot quickly. University extension programs consistently warn against planting tender bulbs in unamended wet soils. You can check local soil prep guidelines via resources like [Clemson Cooperative Extension](https://extension.clemson.edu) to ensure proper drainage techniques. Amending heavy dirt with compost or pine bark fines solves most issues. Aim for a slightly acidic pH around 6.0 to 6.5. ### Container specifications Containers work perfectly if you size them correctly. A five gallon pot represents the absolute minimum volume. Anything smaller restricts the rhizome network and limits final height. Make sure the pot measures at least fourteen inches deep. Shallow pans cause the roots to circle tightly. That leads to stunted growth by mid summer. Use a high quality potting mix that drains fast. Add extra perlite if the bag feels heavy or dense. ### Temperature thresholds Wait until your soil hits 60 degrees Fahrenheit before planting outdoors. Dropping rhizomes into cold spring mud stalls growth entirely. They might even start decaying before temperatures rise. In USDA Zones 3 through 7, treat them strictly as annuals unless you plan to dig them up later. ## Planting, Staking, and Lifting Rhizomes Step-by-Step Growing this cultivar follows a strict seasonal workflow. You cannot just stick it in the ground and walk away. The process shifts depending on your climate zone. Follow these exact steps to avoid losing your plants. ### Spring planting process Start by inspecting your bare root stock. Look for plump sections with at least one visible eye. An eye is simply a small pointed bud where new growth emerges. Discard any pieces that feel hollow or mushy. 1. Dig a shallow trench about four inches deep. 2. Lay the rhizome horizontally with the eyes facing straight up. 3. Backfill gently without packing the soil tight. 4. Water deeply once to settle the dirt around the roots. ![canna rhizome](https://homegardeningblog.com/wp-content/uploads/2026/10/canna-rhizome-muwyep0e.webp) Image source: Bing (Web (fair-use with source credit)) Spacing matters more than people realize. Give each plant eighteen to twenty four inches of room center to center. Crowding them invites fungal diseases. Air needs to circulate freely through those narrow leaves. ### Staking for wind protection Tall spindly stalks snap easily in exposed yards. Install bamboo stakes early in the season. Do not wait until the plant reaches three feet tall. Driving a stake into the ground later risks piercing the underground rhizome network. Tie the main stem loosely using soft garden twine. Leave room for the stalk to expand in girth. Check the ties every few weeks during the summer. Adjust them as the plant pushes upward toward its maximum height. ### Fall lifting and curing If you live outside USDA Zones 8 through 11, winter preparation is mandatory. Wait for the first hard frost to kill the top foliage. Cut the dead stems back to roughly six inches above the soil line. Dig carefully around the base using a garden fork. Lift the entire clump and shake off excess dirt. Let the rhizomes air dry in a shaded spot for three to five days. Direct sun bakes them out too fast. Pack the cured pieces in slightly damp peat moss or wood shavings. Store the boxes in a cool dark location between 45 and 55 degrees Fahrenheit. Check them monthly throughout the winter. Throw away any pieces showing signs of mold or shriveling immediately. ## Spotting the Fakes: Common Misidentification and Pest Mistakes Buying this specific cultivar often ends in disappointment. Big box garden centers rarely carry true orchid flowered types. They substitute cheap standard red cannas and print the wrong name on the tag. Specialty bulb nurseries remain your safest bet for verified stock. Misidentification costs you an entire growing season. You spend months waiting for spidery blooms that never arrive. If the emerging leaves look extremely wide right out of the ground, suspect a labeling error. True 'Robert Kemp' foliage stays noticeably narrower from day one. Pest pressure introduces another layer of frustration. The canna leaf roller causes the most damage to this specific variety. These caterpillars stitch the narrow leaves together using sticky silk threads. Once rolled up, the leaves cannot photosynthesize properly. Inspect the foliage weekly starting in early summer. Unroll any stitched leaves by hand and crush the caterpillar inside. Severe infestations require targeted biological controls. Japanese beetles also love skeletonizing these thinner leaves faster than they attack broad standard varieties. ### Disease warnings Aster yellows presents a serious threat to all cannas. This phytoplasma disease causes distorted yellowed growth. No chemical treatment exists to cure it. If you spot stunted twisted shoots appearing randomly, pull the entire plant immediately. Leaving infected plants in the ground spreads the disease to healthy neighbors. Leafhoppers transmit the pathogen from weed hosts to your garden beds. Keeping the surrounding area free of tall weeds reduces your overall risk. Monitor your plants closely after heavy rain periods when leafhopper populations spike. ## 'Robert Kemp' vs. Other Red Cannas: Which One Fits Your Border? Picking the right red canna depends entirely on your garden layout and visual goals. Standard broad leafed types dominate space quickly. The orchid flowered varieties take a much lighter approach. Knowing the exact differences prevents buyer remorse later in the season. We compared 'Robert Kemp' against three popular alternatives to show you where each one fits best. | Cultivar | Flower Type | Foliage Color | Best Use Case | | --- | --- | --- | --- | | 'Robert Kemp' | Narrow, spidery crimson | Solid green | Airy back borders, texture contrast | | 'Wyoming' | Broad, orange | Deep bronze | Heavy focal points, solid color blocks | | 'Tropicanna' | Broad, orange/red | Striped multicolor | Tropical themes, container centerpieces | | 'Russian Red' | Medium, dark red | Burgundy/green | Dark themed gothic gardens | ### When should you choose 'Robert Kemp' over 'Wyoming'? Choose 'Robert Kemp' when you want height without blocking the view behind it. 'Wyoming' belongs to the Italian group of cannas. It grows incredibly dense and throws wide bronze leaves that act like a solid wall. That works great for hiding ugly fences. But if you have shorter perennials planted behind your canna row, 'Wyoming' will swallow them completely. 'Robert Kemp' lets light filter straight through those narrow stems. Your background plants stay visible and healthy. Aggregate reviews from landscape designers favor this airy habit for layered cottage beds. ### How does it compare to other orchid flowered types? Canna 'Erebus' shares the exact same spidery flower structure. The main difference is color. 'Erebus' produces pale pink or salmon blooms instead of deep crimson. If you need a softer pastel look, 'Erebus' fills that role perfectly. For cut flower growers, 'Robert Kemp' holds up better in arrangements than heavy standard types. Those thin staminodes resist bruising during transport. Florists value that specific durability. You get unique architectural stems that last longer in a vase than broad petaled alternatives. ## Frequently Asked Questions ### Is the robert kemp canna lily toxic to dogs or cats? No, this plant is completely safe for pets. Unlike true lilies which cause severe kidney failure in cats, cannas pose zero toxicity risk. Dogs, cats, and horses can brush against the foliage safely. You can plant them freely in pet friendly yards. ### How tall does this specific variety actually grow? Verified nursery specifications confirm a mature height between 48 and 72 inches. Soil quality and sunlight hours dictate the final measurement. Plants grown in partial shade stretch taller but produce fewer flowers. Full sun keeps the stalks sturdy and compact. ### Can I leave the rhizomes in the ground over winter? That depends entirely on your local climate zone. Gardeners in USDA Zones 8 through 11 can leave them planted with a thick mulch layer. Anyone in Zones 3 through 7 must dig them up before freezing temperatures arrive. Frozen rhizomes turn to mush instantly. ### Why are my canna leaves rolling up tightly? Tightly rolled leaves indicate a canna leaf roller infestation. These small caterpillars use silk threads to stitch the foliage shut for protection. Unroll the leaves manually to find and remove the pest. Severe outbreaks require targeted biological sprays applied directly to the affected areas. ### Does this cultivar attract hummingbirds effectively? Yes, hummingbirds actively seek out these crimson blooms. The tubular base of the flower holds accessible nectar. Because the petals stay narrow and spidery, birds land easily without fighting dense foliage. Planting them near a patio guarantees frequent summer visits.