# Catberry (Ilex mucronata) > A deciduous holly of northern bogs and lakeshores, with red summer berries on thread-like stalks and leaves that feed Columbia silkmoth caterpillars. Also called Nemopanthus mucronatus. Category: Native Shrubs. Grown from seed by Blue Whale Trees. Web version: https://bluewhaletrees.com/plants/catberry/ ![Catberry (Ilex mucronata) bright red berries on long thin stalks among smooth-edged green leaves](https://bluewhaletrees.com/img/plants/catberry-h1610-800.jpg) *Photo: Rob Routledge, CC BY 3.0 ยท [Wikimedia Commons](https://commons.wikimedia.org/wiki/File%3AIlex_mucronata_5499289.jpg)* ## Facts - Type: Shrub - Mature height: 3 to 10 ft - USDA hardiness zones: 3 to 7 - Grows wild in: Stream banks, swamps and wet flats - Native range: 17 states, north and west to Minnesota and south to West Virginia (Connecticut, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia and Wisconsin) - Sun: Full, Part - Soil moisture: Wet, Average - Growth rate: Slow - Traits: Wildlife value, Tolerates wet soil - Sold as: Saplings, Seed Heights and zones are typical ranges for the species in cultivation; local conditions and seed source shift them. ## Availability Not yet priced online. Ask at captain@bluewhaletrees.com or leave an email on the web page to be told when it is listed. ## Notes Catberry is a deciduous holly of northern bogs, swamps and lakeshores, from Newfoundland to Minnesota and south to West Virginia. It was long kept in a genus of its own, but genetic studies show it is a true holly. It looks like our winterberry holly, but its leaves are smaller and nearly toothless, and its berries dangle one by one on stalks up to an inch long. Indiana lists it as threatened. Plant it at a pond edge or in a wet, shaded border, where the red berries show in summer. ## Size, growth and what to expect Catberry grows slowly, about a foot a year in our growth estimator. In a New York peatland, plants stood about 4.5 feet tall at 5 years, 6.5 feet at 10 and 11.5 feet at 20. It makes a many-stemmed shrub 3 to 10 feet tall, and a few reach 15 feet. Its thin leaves run 1 to 2.5 inches long, often with a tiny point at the tip. Small, pale yellow flowers with narrow petals open in May and June. They hang singly on thread-like stalks along the new shoots. On female plants, bright red berries a quarter to a third of an inch across ripen in July and August. Each hangs on a stalk up to an inch long, and birds take most of them before winter. It grows wild from Newfoundland to Minnesota, south to West Virginia, Maryland and Indiana. Its home is bogs, fens, swamps, wet woods and lakeshores on acid peat or sand. In a bog it often stands in the band of tall shrubs at the edge of the mat. Its leaves feed the caterpillars of the Columbia silkmoth. ## How to grow Catberry Catberry grows in full sun or part shade, in a wet, acid soil of peat or sand. Nearly all wild plants grow in wetlands, and it does best where the ground stays wet. Plant it 5 feet from a wall and set plants 5 feet apart. At its size it can go within 15 feet of overhead wires. Saplings ship bare-root or potted. Plant them dormant, from leaf fall until bud swell, in a hole wider than the roots and no deeper. Set the crown at the soil line, put the native soil back in, and keep the mulch clear of the stems. Seed needs a long warm, damp spell and then a winter, and cold alone does not wake it. Sow cleaned seed outdoors in fall, an eighth of an inch deep under mulch. Seedlings come up slowly and unevenly, in the second or third spring. For a spring sowing, keep it in a damp bag at room temperature for two to five months and then in the refrigerator for two to three months. Water weekly through the first two summers unless the ground stays wet. It spreads by root suckers into an upright thicket over the years. It needs little pruning. Most plants are male or female, and only females bear the berries, so plant three or more seedlings for a male and a female. A few plants bear both male and female flowers. Birds eat the berries and spread the seed. As with other hollies, eating the berries can make a person mildly ill. ## Sources - [NatureServe Explorer: Nemopanthus mucronatus, Mountain Holly](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.155240/Nemopanthus_mucronatus) - [USDA Forest Service, Woody Plant Seed Manual (2008), Nemopanthus chapter, Zasada and Schopmeyer](https://www.fs.usda.gov/nsl/Wpsm/Nemopanthus.pdf) - [USDA Forest Service, Woody Plant Seed Manual (2008), Ilex chapter](https://www.fs.usda.gov/nsl/Wpsm/Ilex.pdf) - [Native Plant Network: Schultz, Beyer and Williams (2001), Propagation protocol for Nemopanthus mucronatus plants, USDA Forest Service, Hiawatha National Forest](https://npn.rngr.net/npn/renderNPNProtocolDetails?selectedProtocolIds=aquifoliaceae-nemopanthus-1486) - [Trees and Shrubs Online (International Dendrology Society): Ilex mucronata, from Bean](https://www.treesandshrubsonline.org/articles/ilex/ilex-mucronata/) - [Go Botany, Native Plant Trust: Ilex mucronata, mountain holly](https://gobotany.nativeplanttrust.org/species/ilex/mucronata/) - [Lady Bird Johnson Wildflower Center: Ilex mucronata, Catberry](https://www.wildflower.org/plants/result.php?id_plant=ILMU) - [University of Maine Cooperative Extension: Mountain holly, D'Appollonio, April 2019](https://extension.umaine.edu/blueberries/weed-images/woody-weeds/mountain-holly/) - [Native Gardens of Blue Hill: Ilex mucronata](https://plants.nativemainegardens.org/plants/ilex-mucronatus/) - [Minnesota Wildflowers: Ilex mucronata, Swamp Holly](https://www.minnesotawildflowers.info/shrub/swamp-holly) - [Indiana Department of Natural Resources: Endangered, Threatened, and Extirpated Plants of Indiana, 10/29/2025](https://www.in.gov/dnr/nature-preserves/files/np-etrplants.pdf) - [Maryland Natural Heritage Program: List of Rare, Threatened, and Endangered Plants of Maryland, March 2026](https://dnr.maryland.gov/wildlife/Documents/Maryland-NHP-RTE-Plant-List.pdf) - [Rhode Island Natural History Survey: Rhode Island Rare Plants 2016](https://rinhs.org/wp-content/uploads/2021/08/RI-Rare-Plants-2016-simple-list.pdf) - [USDA NRCS PLANTS Database: Ilex mucronata, ILMU](https://plants.usda.gov/plant-profile/ILMU) - [GBIF occurrence search, preserved specimens of Ilex mucronata in the United States](https://www.gbif.org/occurrence/search?taxon_key=5534659&country=US&basis_of_record=PRESERVED_SPECIMEN) - [NC State Extension Gardener Plant Toolbox: Ilex, the genus page](https://plants.ces.ncsu.edu/plants/ilex/) ## Read before planting - [Ten planting mistakes that quietly kill trees](https://bluewhaletrees.com/articles/ten-planting-mistakes/index.html.md) - [Transplanting young trees: timing, water and protection](https://bluewhaletrees.com/articles/transplanting-young-trees/index.html.md) - [Protecting young trees from voles, rabbits, deer and squirrels](https://bluewhaletrees.com/articles/protecting-trees-from-animals/index.html.md) - [The habitat around a tree is part of the tree](https://bluewhaletrees.com/articles/habitat-around-a-tree/index.html.md) - [Invasive vines and shrubs are what is killing your woods](https://bluewhaletrees.com/articles/invasive-vines-and-shrubs/index.html.md) - [Native trees and shrubs for butterflies and moths: host plants first, nectar second](https://bluewhaletrees.com/articles/native-trees-for-butterflies-and-moths/index.html.md) ## Related - [Planting-site check](https://bluewhaletrees.com/tools/site-check/index.html.md): for a thrive, struggle or fail verdict on Catberry, add ?species=catberry with zone (2 to 10), sun (full, part, shade) and moisture (dry, average, wet) to that address, for example ?species=catberry&zone=3&sun=part&moisture=average. - [Companion species for Catberry](https://bluewhaletrees.com/tools/companions/index.html.md?species=catberry): the natives that share its ground and the plants that pair with it in a yard. - [Growth estimator](https://bluewhaletrees.com/tools/growth/index.html.md): how the height and trunk projections are made; the estimate itself runs in the browser at https://bluewhaletrees.com/tools/growth/#species=catberry - [Seed sowing planner](https://bluewhaletrees.com/tools/sowing/index.html.md): how Catberry is sown, in the chart for every species (treatment, cold days, depth, timing); the dated plan runs in the browser at https://bluewhaletrees.com/tools/sowing/#species=catberry - [Pollination planner](https://bluewhaletrees.com/tools/pollination/index.html.md): what Catberry needs for a crop and how many to plant, in the table for every species; the planner runs in the browser at https://bluewhaletrees.com/tools/pollination/#plants=catberry:3 - [Bloom and fruit calendar](https://bluewhaletrees.com/tools/calendar/index.html.md): the months Catberry flowers and fruits, in the grid for every species.