Garden Notes : Busyseason
On Saturday, May 23, the Polly Hill Arboretum (PHA) visitor center opens for the season, with daily hours from 9:30 am to 4 pm. Staff members lead tours every day at 2 pm. The grounds are open year-round, from sunrise to sunset. The Arboretum's plant sale area also opens for the season this Saturday with a choice selection of unusual trees, shrubs, and perennials. Arboretum staff have chosen and grown plants that are noted for their superior ornamental qualities and their adaptability to Island conditions. Staff will be on hand to answer your questions. More information about other PHA activities is available at pollyhillarboretum.org.
May: Green goddess
The past two weeks have seen the yearly dramatic color shift in the landscape, from neutral to green and flowery. Suddenly the world is brimming with colors, scent, and birdsong. The down-Island towns are practically in summer mode, while the more rural Island landscape, dominated by oak woodland, tarries somewhat. By now we know how many flower-heads the lilac has, how much new growth the Japanese maple put out, and whether the peonies and iris will have the desired (or any) number of flower stems.
We may also have observed uninvited plants: I am talking about the brute invaders, invasive exotics. Seeds or roots of oriental bittersweet may arrive in construction fill used in various ways around homes or those of neighbors. Mugwort has an affinity for nursery-raised pots and root-balls. Ruderal areas like roadsides, drainage areas, or back lot-lines host rubbishy plants like Japanese knotweed, Norway, and sycamore maples, weed honeysuckles, and autumn and Russian olive. These plants have the capacity to muscle out native plants and designed ones alike, in the landscape. To view the Massachusetts Prohibited Plant List, go to mass.gov/agr/ farmproducts/proposed_ prohibited_plant_list_v12-12-05.htm. For images, click on the common names.
One of the fastest increasing invasive plants around the Vineyard is garlic mustard, Alliaria petiolata, stands of which I see nearly every day. It just springs up. Though it is innocuous looking, with its fresh green leaves and topknot of small white flowers, prolifically spreading alliaria secretes a substance that interferes with the mycorrhizae that trees need to grow, and is a threat to woodlands. Even plants that were originally desired and not on the Prohibited Plant List, like wisteria, can get out of hand. I have known a couple of properties where considerable area was "lost" to the jungly tangle of its tree-like vines that covered the ground and woods.