H
- HACKBERRY
- HAIR GRASS
- HARDY ORANGE, TRIFOLIATE ORANGE
- HARDY RUBBER TREE
- HAWAIIAN TREE FERN
- HAWORTHIA
- HAWTHORN
- HAY-SCENTED FERN
- HEATH
- HEDGEHOG CACTUS
- HELICHRYSUM
- HELIOTROPIUM
- HELLEBORE
- HEMLOCK
- HEN AND CHICKS
- HERALD’S TRUMPET, EASTER LILY VINE
- HESPERALOE
- HIBISCUS
- HICKORY
- HOLLY
- HOLLY FERN
- HOLLYHOCK
- HONEY LOCUST
- HONEYSUCKLE
- HOP
- HOP HORNBEAM
- HOP TREE
- HOREHOUND
- HORNBEAM
- HORSECHESTNUT, BUCKEYE
- HORSERADISH
- HORSETAIL
- HOUSELEEK
- HOUTTUYNIA CORDATA
- HOWEA
- HYACINTH BEAN
- HYDRANGEA
- HYSSOP