Name (Common)Name (Latin)ImageCarbon SpongeTypeSoilpHH20Annual/Perennial/BiennialCool or Warm Season?When to plantWhen bloomsHarvestZone (if P)SunlightRoot DepthPlant HeightNitrogen FixingScavengingCarbon BiomassPollinatorPestsCompanion PlantingNot CompanionHuman Food & Other UsesLinksMore LinksComments
This is the Carbon Sponge Plant Database started in 2018. If you have suggestions, please email
Alfalfa/ LucerneMedicago sativa
NYSCI, PWLegumeLoose6.8-7.5ResilientP Spring (or in Fall)At the early stage of flowering3-7Full sun10' (and lateral 5" only)2'YesSproutsEat as a herb. Often mix with oats to suppress weed. Improve drainage & encourage fungi for soil structure. Plant releases acid exudates to break the bond between calcium and phosphate in your soil. Holds moisture and prevents erosion. High nitrogen and therefore a great mulch or to heat up compost pile.
AlyssumLobularia maritima
NOT YETFlowering plantWell amended with good drainage. Older varieties are tolerant of poorer soils and somewhat dry conditions.6-7Well drainedAWDirect sow when a slight risk of frost still exists. Does not need to start inside. Alyssum needs light to germinate, just press them into the top of the soil and do not burry them. Keep the soil evenly moist but not wet.SummerAnnual up to Zone 8; short-lived perennial in Zones 9-11.Full sun to partial shade4-10" tall, sprawlsYesYesFast-growing, low (20-30cm) pretty white flowered plant. Alyssum can be seeded densely to protect soil and suppress weeds, and is great for drawing in beneficial insects. Broadcast to smoother weeds. Alyssum can be tilled under or cut and composted at the end of the season. Avoid following this cover crop with other Brassicas. Excess moisture in the soil causes Alyssum to grow very vigorously.
Barley, WinterHordeum vulgare
NOT YETGrass, cereal grainWide-range6-8.5DryACoolSeptember 1 - October 158 or warmer6.5'2-4'YesYesProtects vegetable crops such as carrots and onions that are vulnerable to wind damage. Provide protection to fragile red clover or sweet clover seedlings. Does not compete with alfalfa. scavenger of N, more tolerant of low fertility, excellent drought tolerance, exceptional erosion control and excellent weed suppression. Thick and deep roots. Phytolith.
Black-eyed Susan/RudbeckiaRudbeckia hirta
WFFFlowering plantWide-range<6.8Medium, Dry, Moist, Well drainedBearly fall or springJune-Sept4-9Sun but tolerate shade8"1-3"YesYes control. Do fine in clay. Good for raingarden. Can be heavy seeders. Native to eastern US and has been used for centuries as a medicinal herb by various native North American tribes. Mycorrhizal species.
BuckwheatFagopyrum esculentum
NYSCI, PWFlowering plant, Pseudo-ceral or non-grass course grainWide-rangeTolerantWell drained ASpring70-90 days. (Buckwheat has to be chopped or mowed after flower blooms. Otherwise, the plant will go to seed and spread. Going to seed has ecological advantages but may want to be avoided. Buckwheat grows quickly in early summer which is why it is so useful. After planting it will flower in six weeks. You can mow it and let it regrow several times a season to extend benefits.)Warm season (not frost tolerant)Shallow depth (laterals 3-4')3'Yes YesYesBrussels Sprouts and Kale. Mixes well with upright flowersKasha, Soba noodles. Honey made by bees that collect nectar from buckwheat flowers is highly nutritious. weeds and grubs by plant-produced natural herbicides (allelopathy). Mines phosphorus and calcium from deep in the soil. Possibly secretes acids into the soil that put P into a more soluble, plant-usable form. Fast growing and fast to flower/seed. Supports high densities of beneficial insects. Gluten free. Roots exudates are specially acidic. Almost always have more available P after a buckwheat crop.
Cereal, Rye Secale Cereale
Cereal grain 5.5-7.0Dry, MoistACoolEarly FallFall, within 7 days 120-150 days3-7
Clover, Berseem (Egyptian Clover)Trifolium alexandrinum
LegumeWide-range but silt loam best6.2-7Low to mediumAEitherearly spring or early fall6-8"1-3'YesYesYesOat, ryegrassNitrogen heavy, fast growing, won't over winter or reseed. Provides good ground cover. Outcompetes weeds. Multiple cuttings/mows to achieve highest N. Ideal winterkilled cover before corn or other nitrogen-demanding crops.
Clover, CrimsonTrifolium incarnatum
NYSCI, PWLegumeWide-range but best in sandy loamMid-rangeWell drainedA (reseed)late summer6-10Full Sun1'1-3'YesYesYesRabbitsRye and other cereals, vetches, annual ryegrass, subclover, red clover, black medic suppressor, Provides good groundcover and weed control as it fixes nitrogen from the atmosphere and scavenges nitrogen from the soil; buy inoculated seed; provides nitrogen and carbon to soil.
Clover, RedTrifolium pratense
NOT YETLegumeMoist5.5-7.5Well drained, resilientBSpring, Summer or Fall3-9Full sun2-3' (big root mass and deep for only 2" above ground)1-3'YesYesYesPotatoes, cucumbers, corn, strawberries, celery, summer savory. Do not plant with onions or garlic. suppressor, deep roots and big biomass. Aleviates compaction near surface. Medicinal properties.
Cow pea (field pea, black-eyed peas)Vigna unguiculata
NYSCI, PWLegumeWide-range5.5-6.5Low to mediumASpring (after frost)Warm season8'3'YesYesoilseed radishHoppin Joe, Lobia curryGrow very quickly; quickly shade the soil to block out weeds; Hoppin' John dish popular with African slaves and served for good luck on New Year's Day. Not really a pea. Drought tolerant.
DaikonRaphanus sativus
NYSCIBrassicaAerated, rich (when grown for food)5.8-6.8DryACoolMid summer- Early fall2-11Full to partial1-2'2-6"NoYesFoodFukuoka wrote that the name for the wild ancestor of daikon translates as "the herb that soften’s one’s disposition". Topping its mighty roots, daikon wears a crown of broad, 2-3 foot long leaves. Quick-growing, these leaves cover up to 80% of the soil surface, keeping it weed-free and mulched over the winter. We have used daikon in our winter covercrop mix to help aerate the soil and also scavenge nutrients to prevent from leaching. The broad leaves also cover soil to protect, prevent weeds and create green mulch for spring.
False Indigo Bush
Amorpha fruticosa
NOT YETLegume, ShrubWide range 5-8.5Low to medium, resilientPScarify seeds, best started indoors, plant outside during Spring to FallApril-June4 to 9Sun , Part Shade6-14'Medium ( serious insect or disease problems.
Susceptible to leaf spot, powdery mildew and rust of occasional flooding as well as poor, sandy, somewhat dry soils. It is considered weedy/invasive in some parts of northeastern an northwestern. Erosion control.
Fava bean (or broad bean) Vicia faba
NOT YETLegumeWide-range4.5-8.3Well drainedAAprilFull sun to partial shade3-4'2-5'YesYescarrots, lettuce, marigolds, celery, peas, potatoes, parsnip, cabbage, parsley, eggplant. beetroot, onions & garlic, kohl rabi, sunflowers and Jerusalem artichokes.Ful medames, fava bean dip, faba bean pastaBroad beans, need good levels of calcium and magnesium to grow successfully, cool and damp conditions needed. Weed suppression, water filtration qualities and prevents soil erosion.
FlaxLinum usitatissimum
PWFlowering plantRich5Low to mediumCoolEarly springMayShallowSorghumflax seed, linseed oil, textiles for both fibre (production of fabrics, health food (rich in Omega-3), grows best in temperate climates, adapts to a variety of soils. As a cover crop, flax helps to mobilize phosphorus in the soil and add organic matter. A good companion seeding crop for use with small seeded grasses and legumes due to its early maturity, limited leaf area, and less extensive root system.
Gray Alder
Alnus incana
NOT YETShrub TreeWide-range 6.8-7.2Moist PSaplings can be planted in Spring/FallMarch-May2 to 6Sun, Part Shade12-36'YesYes and flood tolerant, good for erorsion control, Native Americans used for medicine
Apios americana
NOT YETHerb VineWell-drained sandy soil4.5 - 7.0MediumP
Fall through Winter
July-Sep3 to 10Shade0-1'YesYes can be invasive once they are established and have become a weed of cultivated cranberry crops in N. America
HoneybushMelianthus major
NOT YETShrubPSow seeds indoors 6-8 weeks beforre last frost.Late spring - mid summer8-10YesNative of South Africa, Will Grow in Southern US or milder climates; All parts of plant are poisonous if ingested
Kenaf (Indian Hemp)Hibiscus cannabinus
MS, WFFHeavy, well drained (but does OK on various types)MediumWarmEarly May through mid June8-14'A fiber plant native to east-central Africa where it has been grown for several thousand years for food and fiber. Source of textile fiber for such products as rope, twine, bagging and rugs. Kenaf absorbs more carbon dioxide from the atmosphere than any other crop
KohlrabiBrassica oleracea var. gongylodes
NOT YETBrassicaWell drained and fertile6-7.5Well drainedAColdEarly spring or late summerBeans, beets, dill, nasturtium, sweet alyssum
Lentil, FieldLens culinaris
NOT YETLegumeLow to mediumAColdEarly springSpring - 10 days80-110 days1-2.5'YesLow growiing nitrogen fixer. Some varieties cold hardy. Lentils may deplete soil moisture if not terminated before pod set and they are not very weed competitive.
Medic, Burr or BlackMedicago lupulina
NOT YETLegumeLowEarly springSpringYesAntibacterial qualities and may be effective as a mild laxative a weed, N source, soil quality builder, weed suppressor, erosion fighter
Millet, BrowntopUrochloa ramosa
NOT YETGrassLowLate Spring, SummerAttracts birdsSometimes grouped with cereal but a grass; It was introduced to the United States from India in 1915. Fast growing. Allelopathic. Prevent erosion. Accumulates lead and zinc making it an important plant for remediation of contaminated soils.
Mung Bean
Vigna radiata
NYSCI, PWLegumeWide-range6.0-6.9Drought tolerantAMay - early JuneSummerFull2-4'3'YesMajor pests: Helicoverpa, Pod-sucking bugs, Mirids, Bean-pod-borerDal, curry, patties crop, health benefits due to high antioxidant levels, can be used as green manure crop, hosts nitrogen fixing bacteria.
Mustard, Yellow (Indian)Brassica juncea or Sinapis alba
NYSCI, PWBrassicaRange (but not good in sandy)6-7.5Well drainedASpring or FallBlooms approximately 6 weeks after sownSun (but can withstand some shade)Large taproot 5" long, 18" 3-5'NoYesYesYesFlea beetles.Condiment, seeds, salad man chewed mustard seeds; Nematode and weed supression; Many people eat leafy greens but not root, many species. Produces large amounts of biomass containing high levels of glucosinates that break down into compounds toxic to nematodes and soil-borne disease-causing organisms. Rapid growth. Scavenging nutrients. Deep roots. Brassicas produce compounds, called glucosinolates, which are toxic to soil-borne pests and pathogens. Mustards usually have higher concentrations of these chemicals. More than 100 different glucosinolates are found in brassicas. Breakdown products from glucosino- lates are volatile and similar to the ac- tive chemical in the fumigant Vapam. Glucosinolate concentrations differ according to plant part, age, health, and nutrition. Despite this complex- ity, Gruver said there is evidence that brassica cover crops can be used to reduce pests, pathogens, and weeds if the right species/cultivar is planted and managed strategically.
New Jersey tea, redrootCeanothus americanus
NOT YETShrubWell-drained6.8-7.2Low to mediumPFall - early WinterMar - Apr4-8>14"1-3'LowYesTea dried leaves can be made into tea (popular during Revolutionary War). Also very adaptable. Its deep roots make already-established plants difficult to transplant.
OatAvena sativa
MS, WFFCereal, GrainWide-range4.5 - 6MediumACSpring or FallLate SpringFull Sun8"2-4'NoYesYeswind pollinated Winter Peas and Winter Field BeansOatmeal, soil softener, fast growing (especially in fall).
Pigeon PeaCajanus cajan
NYSCIShrubWide-range7.5-8.5Low to mediumPAfter last frostTwo months affter sownPartial Sun5-6'1-12ft (Depends on cultivar)YesAttract beesmoths, cutworms, thrips, mirids, green stink bugs, caterpillars Dal origins wherer it is grown as food crop. Is often grown a cover crop. Short perennial shrub and lives about 5 years. Has yellow or red flowers.
Radish, Field or ForageRaphanus sativus L. var. niger J. Kern.
NYSCIBrassicawell drainedAC/WEarly FallYY compaction, aerate soil, ground cover but does not compeat. hey are excellent at breaking up shallow layers of compacted soils, earning them the nickname “biodrills” or “tillage rad- ishes.” Once planted in late summer, the radishes are not harvested but die in the winter, decay, and contribute a nitrogen store for spring planting. Dying off in the winter, the radishes leave root channels so that soil dries and warms up faster in the spring.
Radish, OilseedR. sativus L. var. oleiformis Pers.
NOT YETBrassicaWell drained AC/WYYLike field or forage radish but a bit more winter hardy. hey are excellent at breaking up shallow layers of compacted soils, earning them the nickname “biodrills” or “tillage rad- ishes.” Once planted in late summer, the radishes are not harvested but die in the winter, decay, and contribute a nitrogen store for spring planting. Dying off in the winter, the radishes leave root channels so that soil dries and warms up faster in the spring.
Rapeseed, CanolaBrassica napus
NOT YETBrassicaLoamy, clay-loam, or gravel6.0-7.2MediumAFall or SpringFall, Winter and SpringFull Sun6"3-5'NoYes by bees activity against plant parasitic nematodes as well as weeds. Some winter-type cultivars are able to withstand quite low temperatures.
Rattlesnake masterEryngium yuccifolium
NOT YETHerbWide rangeLow to mediumPFallJune-Sept3-8Full SunDeep tap rootNoProvides habitat American Prairie Native; carrot family (Apiaceae). Can be an aggressive self seeder, remove seed heads if neede, can grow in bog or pond area, attracts native bees
Roundhead bush clover
Lespedeza capitata
NOT YETHerbLoamy sand or rocky 6.5- 8DryPLate Summer - Early Fall Jul-Sep 4 to 8Full Sun2.5 meters3-6'.YesYes (bumblees) mixes well in a naturalized setting with a mix of wildflowers.
Silver buffaloberry
Shepherdia argentea
NOT YETDeciduous shrubWide-range 7.00-8.00Low to mediumPMarch 3 to 9 Full sun to part shade 8-12'YesYesMay be subject to a heart rot disease
which can cause serious problems. There are no
known serious insect problems. poor dry soils, drought and some flooding
SorghumSorghum bicolor
PWGrassWide-range6-7.5Resilient A/PWarmMid May - early June110-120 days4-6'Yesmung beans, guar, crimson clover, flax and buckwheatPopped, coffeePhytolith-occluded organic carbon plant, one of the oldest heritage grains, Eqyptians grew sorghum.
Sorghum Sudan GrassSorghum drummondii
NYSCIGrass5.5-7.5ResilientAWarmSpringMid-JuneCut late summer when 20-30 inches tall, leaving a 6 inch stubble.Heat tolerantFast growing5-12'YesYesBuckwheat, sesbania, sunnhemp, forage soybeans or cowpeas between sorghum and sudangrass, weed/nematode control, subsoil loosner, biomass booster. Leave residue on the soil surface for weed suppression and incorporate biomass into soil. Phytolith-occluded organic carbon plant.
Sunn HempCrotalaria Juncea
NYSCILegumeWide-range5-7.5Well drainedAEarly June (use cowpea inoculate)Tropical (but can grow in summer in US)Large, strong taproot3-9'YesNoNoFights Nematodes, biofertilizer or mutual relationship with Rhizobacteria (hence N fix)
NYSCIFlowering plantLoose, needs depth; loamy sandy5-8Well drained, drought tolerantAWarmAfter last frost, continuous planting in summer and even late summer or early fallSummer or FallFull sun1-3'2-10'NoYesYesIt is best to not plant sunflowers more than once every three years in a given field to help minimize any potential diseases or other pest problems.Starting to be used in cover crop mixes for deeptap root, bird attractor and beauty. Oil, seed seeds when back of the flowers turn brown, myth that they are efffective phytoremediators (remove toxins); native to US, deep taproots, suppress certain weeds
Sweet fern
Comptonia peregrina
NOT YETShrubSandy, acidic soils<6.8DryPMay-Aug2 to 6Part Shade1-3'YesYes (butterflies) No serious disease or insect problems. does not tolerate shading
well, so removing competing vegetation is important.
SwitchgrassPanicum virgatum
NOT YETGrassWide-range5 or higherResilientPJuneMid-summer3-10Full sun10-11'YesDense cover for wildlife, esp in winterWidespread in US before settlers, plains, grows in clumps, can grow to 6' tall, sturdy and cold weather resistant
Thistle, Blue Glow GlobeEchinops bannaticus
NOT YETFlowering plantWide-range6.1-6.5Well drained, dry, reslientPMid to late Summer3-9Full Sun2-4'Yesbeardtongue and yarrowsNative, good for liver health, Canadian thistle deep and expansive root system & considered invasive
NYSCI, PWLegumeWide-range6-7MoistASummer orr FallEarly Springfull-partial12"4'lowYes (bumble bees) vetch helps with the suppression of spring weeds. Weed suppression is increased when the legume is associated with a cereal companion crop. Research has shown that hairy vetch mulch can increase main crop disease resistance and prolong leaf photosynthesis of the following crop.
Violet Bush CloverLespedeza violacea
NOT YETHerbDry, sandy4.1-4.3DryPJune-Julypartial sun0.5–2'Yes from taller and more aggressive ground vegetation is not well-tolerated.
Virginia springbeautyClaytonia virginica
NOT YETHerbRich, moist soils. Prefers high humus<6.8MoistPPropagate seeds and sow as soon as seeds ripenJan - May3-8Part shade0-1'NoYes (bumble bees)Can become weedy if conditions are too goodGrows from a tuber that is edible (its flavor being described as sweet and chestnut-like). a variety of soils. Grows rapidly. Grown from tuber. Disappears from above ground after seed capsules ripen, but doesn't leave a gap in the garden. First Nations and colonists used them for food and they are still enjoyed by those interested in edible wild plants. (Niering)
Winter Peas (Austrian, field)Pisum sativum (subspecies arvense)
NYSCIVine, legumeWide-range but grow best on fertile,
light-textured, well-drained soils
5.5-7.0Well drainedASpringSummerFull2-9'YesCereal, Wheat, Rye and OatsWeedsNot peas for eating
Winter Rye GrassLolium perenne
NYSCIGrassWide-range5-7Resilient ACoolFall3-5'12-18"NoYesYesCan be grown in mixtures with a legume such as hairy vetch and/or crimson clover. hardiest of cereals, rye can be seeded later in fall than other cover crops and still provide considerable dry matter, an extensive soil-holding root system, significant reduction of nitrate leaching and exceptional weed suppression. Thick roots.
YarrowAchillea millefolium
NYSCIFlowering plant4.7-8Drought tolerant, resilient PJune-OctThrough summer3-9Full sun, heat8".5-3'liatris, penstemon, and VeronicaNative, hearty, deadhead to make bloom more, used to treat wounds
Trees and Shurbs
Wax Myrtle
Buffaloberry, Bullberry
Black Locust