Plants brought into Maine must:
- be apparently free from plant pests,
- have an inspection certificate issued by the appropriate regulatory agency of the state of origin attached to each package (Title 7 MRSA sec. 2214, Title 7 MRSA sec 2215)
- meet the requirements of any quarantines maintained by the state or federal government that restrict the movement and sale of some plants to prevent the spread of plant pests.
An inspection certificate is a document issued by the appropriate regulatory agency, usually the department of agriculture, of the state of origin stating that the nursery or premises that the plants came from has been inspected and found to be free from pests.
Maine has several quarantines in place to protect our plant and natural resources from harmful insects, diseases and plants. The following are some of Maine's regulations pertaining to plants commonly sold by the nursery industry. Please keep these regulations in mind when you are ordering and receiving shipments of plants .If your nursery in Maine is currently in possession of any of the plants mentioned here please contact Horticulture to discuss how to best dispose of them.
Hemlock woolly adelgid (HWA) quarantine
- Hemlock trees are only allowed from certain areas with certification paperwork
HWA is a serious pest that attacks and kills hemlock trees, an important landscape and forest species in Maine. This pest is commonly found in many states, but its distribution within the state of Maine is limited. The further spread of HWA on hemlock nursery stock is of great concern. For this reason Maine maintains a quarantine regulating the movement of hemlock plant material into and within the state.
To meet the requirements of the HWA quarantine all hemlock plants coming into non-quarantined areas of Maine must originate from areas where HWA is not established and shipments must be accompanied by a certificate issued by the plant protection organization of the origin state.
More information on Importing Hemlock.
White pine blister rust (WPBR) quarantine
- Currants and gooseberry plants cannot be sold in most areas of Maine
WPBR is a serious disease of white pine, a major forest and economic species in Maine. WPBR weakens and kills infected trees and can prevent the regeneration of white pine in some forest areas. In addition to infecting white pine, WPBR also infects Ribes species (currants and gooseberries). Ribes spp. play an important role in the survival and spread of the disease. Infections of WPBR cannot be passed from pine tree to pine tree, but must infect a ribes plant to spread to pine. For this reason the sale, transportation and possession of Ribes spp. is illegal throughout most of Maine and the sale of Ribes nigrum (black currant) is illegal in the entire state of Maine. Some Ribes spp. (including red currants) may be sold in extreme northern and eastern portions of Maine.
More information on WPBR from the Maine Forest Service including a map of where some Ribes spp. may be planted.
Banned invasive aquatic plants
- Eleven aquatic plants cannot be sold in Maine.
The Maine Department of Agriculture, Conservation and Forestry along with the Maine Department of Environmental Protection are concerned with the introduction of foreign and invasive aquatic plants to Maine's waterways. The State of Maine has a law banning the sale, propagation and introduction of eleven aquatic plants considered invasive. These plants are:
- Brazilian elodea (Egeria densa),
- hydrilla (Hydrilla verticillata),
- curly leaved pondweed (Potamogeton crispus),
- parrot feather (Myriophyllum aquaticum),
- European frogbit (Hydrocharis morsus-ranae),
- variable leaf milfoil (Myriophyllum heterophyllum),
- European naiad (Najas minor),
- water chestnut (Trapa natans),
- Eurasian milfoil (Myriophyllum spicatum),
- yellow floating heart (Nymphoides peltata),
- Fanwort (Cabomba caroliniana).