Scientific Name

Common Name

Methods of Propagation

Time Period

Comments/Requirements

Habenaria sp.

Fringed Orchids

D, S

Haberlea sp.

S

as Ramonda

D

LC

Hacquetia epipactis

S

fresh seed

D

early spring

use care

RC

Hakonechloa macra

TC

D

Halacsya sendtneri

S

SC

summer

needs ophite stone

Haplocarpha sp.

S

early spring

SC

summer

heel

Haplopappus sp.

S, D

SC

semi-ripe, sandy mix

Haplophyllum patavinum

S

self sows

D

Harpalium: see Helianthus

Hebe sp.

SC

late summer

heel, semi-ripe

S

seedlings variable, 3-4 years to flower

Hedera

SC

Hedyotis: see Houstonia

Hedysarum sp.

French Honeysuckle

S

spring

sow ripe seed

L

D

spring

established plants, use care

Helenium sp.

Helen's Flower/Sneezeweed

S

SC

spring, early summer

basal, soft growth best

D

spring

Heleocharis: see Eleocharis

Helianthella sp.

S

as Heliopsis

D

Helianthemum sp.

Rock Rose

S

species

SC

summer, early fall

heel, after flw

D

spring

may be difficult

H. nummularium

Sunrose

SC

softwood - young shoots in spring

Helianthus sp.

Sunflower

S

SC

basal, soft growth best

D

after flw

Helichrysum sp.

Everlasting

S

prefers sandy soil

D

some sp.

SC

semi-ripe tips, woody sp.

Heliconia sp.

D

of rhizomes

TC

from rhizome buds

Helictotrichon sp.

Oat Grass

D

spring

S

cold to germinate

H. sempervirens

S

sow fresh

Heliohebe hulkeana

SC

late summer

heel, semi-ripe

S

seedlings variable, 3-4 years to flower

Heliopsis helianthoides

Oxeye Daisy

S

reliably true

SC

spring

prior to budding

D

spring, fall

Heliosperma: see Silene

Helipterum sp.

Everlastings

S

as Helichrysum

Helleborus sp.

Hellebore

D

of crown; roots and leaves poisonous

D

spring

of roots, not H. foetidus, difficult

S

sow fresh, flw 2-3 years

SC

young vegetative shoots

Heychium sp.

Ginger Lily

D

of rhizome

Helonias bullata

Swamp Pink

S

sow fresh

D

tubercles, after flw, usual method

Heloniopsis orientalis

S

spring

or ripe

D

after flw

Hemerocallis sp.

Daylily

D

rooted sections with 3 offshoots each

D

spring - fall

mature plants, cut back leaves to 6"

TC

flower petals and sepals as explants

S

breeding

Hepatica sp.

Liverleaf

S

early summer

may take 1-2 years to germ.

S

sow outside

D

early spring

before growth

D

spring, fall

older clumps, doubles

Heracleum sp.

Hogweed

S

ripe

D

rootstock, toxic sap

Herniaria sp.

Rupturewort

D

spring

short-lived

SC

bottom heat

S

short-lived

Hertia: see Othonna

Hesperaloe sp.

S

as Nolina

D

spring

offsets

Hesperis sp.

Rocket

S

spring, fall

usual method

SC

spring

double forms, basal

D

fall

when dormant

Hesperochiron sp.

S

as Romanzoffia

Heterotheca sp.

Golden Aster

D

S

self sows but invasive

Heuchera sp.

Coral Bells

D

dormant crowns

D

spring, early fall

single divisions of clumps

TC

stem explants

S

spring

not cvs

LC

SC

avoid heat

x Heucherella sp.

D, SC, LC

Hexastylis: see Asarum

Hibanobambusa tranquillans

Bamboo

D

Hibiscus sp.

Mallow

D

fall, spring

fall easier

L

summer

SC

spring, early summer

shrubby sp., bottom heat

S

spring

TC

Hieracium sp.

Hawkweed

S

not H. x rubrum

D

also runners

Himalayacalamus hookerianus

D

Hippeastrum sp.

Amaryllis

D

of bulb offsets

S

take 2-4 years to flower

TC

twin scaling

Hippocrepis comosa

Horseshoe Vetch

S

spring, fall

transplant early, may self sow

D

SC

non-flw stems

Hippolytia (Tanacetum) herderi

S

SC

summer

softwood, with heel, alpines

Hippuris vulgaris

Mare's Tail

SC

Holcus sp.

D

spring

S

species

Homogyne sp.

S

ripe, fresh

D

Hoorebekia: see Grindelia

Hordeum sp.

Barley

S

Horkelia sp.

S

Horminum pyrenaicum

Dragon Mouth

S

self-sows, preferred method

D

spring, fall

Hosta sp.

Plaintain Lily, Funkia

D

spring, early summer

most common, single eye

TC

S

breeding, not true, species

Hottonia sp.

Water Violet

S

keep wet

D

SC

in water or mud

Houstonia (Hedyotis) sp.

Bluet

S

spring

see Galax

D

spring, fall

Houttuynia cordata

D

spring

SC

spring, summer

S

Hoya sp.

Wax Flower

SC

use bottom heat, single node

Hugueninia tanacetifolia

Tansy-Leaved Rocket

S

Hulsea sp.

S

D

as Andryala

Humulus sp.

Hops

D

early spring

S

fall

not for cultivars

RC

sucker shoots

SC

spring

semi-soft

Hutchinsia (Pritzelago, Thlaspi) alpina

S

spring, fall

sow fresh or stratify

D

spring

base cuttings

SC

summer

soft

Hyacinthella sp.

S

sow fresh

D

offsets after flw

Hyacinthoides sp.

Wood Hyacinth

S

spring

or when ripe

D

bulblets

Hyacinthus orientalis

Hyacinth

TC

bulb, leaf, infloresence, or stem as explants

S

may take 6 years to flower

D

fall

bulbils from "scoring" bulbs

Hydrastis canadensis

Golden Seal

D

fall

rhizome, after foliage dies

S

sow ripe, slow

Hydrocharis sp.

Frogbit

S

keep wet

D

winter

buds on pond bottom

Hydrocotyle sp.

Pennywort

D

rooted stems

S

Hydrophyllum sp.

Waterleaf

S

D

spring, fall

Hylomecon japonica

D

spring

as Chelidonium

S

Hylotelephium: see Sedum

Hymenocallis sp.

Spider Lily

TC

D

offsets

S

Hymenoxys sp.

Alpine Sunflower

S

D

some sp.

Hyoscyamus sp.

Henbane

S

summer

old seed erratic germ, self sows

Hypericum sp.

St. John's Wort

D

of crown

S

spring

see Alcea, sow fresh

SC

summer, fall

basal softwood, terminal fall

D

spring

layers

Hypochaeris sp.

Cat's Ear

S

as Arnica

Hypolepis sp.

S

spores self sow

D

defoliate before rooting

Hypoxis sp.

Star Grass

S

D

summer

just after flw

D

fall

short runners

Hyppolytia: see Hippolytia

Hypsela sp.

D

spring

Hyssopus officinalis

Hyssop

S

SC

early summer

softwood

Hystix patula

Bottle Brush Grass

D

spring

S