“Camellias in bloom are among Polly Hill Arboretum’s many flowering attractions. Plant sale is May 29.”
Catching up, keeping up
This year we are enjoying an early, extravagant spring such as I cannot ever remember having experienced on the Island. I was in a garden where lilac, iris, and narcissi were in bloom concurrently, on April 23! A trip to the Arnold Arboretum for Lilac Sunday (May 9, the second Sunday in May) is a wonderful family field trip. If a mainland trip is out of the question, come to Polly Hill Arboretum and admire the two dozen or so lilac varieties growing there, and much else as well.
Unavoidable absences from home led us to a pile-up of work in the vegetable garden. We spent a frenetic weekend planting, weeding, shifting, and re-organizing. However, the unavoidable truth about gardens, and most especially vegetable gardens, is that everything must be done on time and at the right time. Anything less is second best, because the season and the plants do not wait.
Exercise care in lawn treatments. Don’t let an emerald green lawn and the pride you take in it come at the expense of Island fishermen’s livelihoods. We need clean bays and harbors.
Hemlock Woolly Adelgid: Hopeful Signs
I was spraying our hemlocks (both Tsuga canadensis and T. carolina) with horticultural oil for hemlock woolly adelgid. Although I knew we had had a small HWA infestation for several years, I was hopeful that the recent winter’s prolonged cold had given the cottony white, aphid-like insects a whack.
However, when I spotted a couple of diminutive, rotund black beetles in place on different branches — well, you may imagine my bated breath, because as far as I could see, they resembled the images of Sasajiscymnus tsugae (formerly Pseudoscymnus tsugae), the introduced ladybug that I had seen at a hemlock lecture.
Although I stopped spraying, I failed to collect either of the two beetles I had seen. They are minute, somewhat resembling a smallish privet berry, and the initial one did not resonate with me until I saw the second, which I brushed protectively to the ground after a glance; and then I failed to find the first one.
In the 1990s, as hemlocks throughout the eastern United States began to be devastated by HWA, homeowners, foresters, and entomologists alike were wringing their hands. The fate of these conifers appeared to be sealed, especially in the southeastern U.S., where majestic Appalachian stands of Tsuga caroliniana stood ravaged and ghostlike.
It was surmised that climate disruption and the trend for warmer winters were responsible for the northward spread of the agent of destruction, the hemlock woolly adelgid; and it was feared that soon hemlocks and the myriad life-forms they support, the complex hemlock forest system, would be going the way of the American chestnut.
Intense researching for controlling organisms began, primarily in China and Japan, and eventually Sasajiscymnus tsugae, an Asian ladybug, was selected as the best bet for production and release in the U.S. It feeds exclusively upon HWA. Field releases of S. tsugae began in Connecticut in 1995 and elsewhere in 1999. Since 1995, more than one million S. tsugae have been released on more than 100 sites in 15 eastern states, from South Carolina to Maine, according to the University of Rhode Island website.
I hope that what I spotted are the introduced ladybugs and that they are establishing themselves on the Vineyard. Although not the most commonly planted Island conifer, there are many beautiful hemlocks on the Vineyard. If you observe a similar insect on the branches of your hemlocks, please collect it in a small container and contact your town’s tree warden.
While waiting for the protection that Sasajiscymnus tsugae may afford Island hemlocks, support your hemlocks by giving them a good watering during dry spells. The URI website says one inch per week, perhaps best delivered via black leaky hose. Lay one to two inches of mulch out to the drip line, but keep it away from the tree trunk (no mulch volcanoes). Avoid fertilizing, which may actually abet any infestation of HWA that may be present. Prune away dead branches, promoting good ventilation in the tree.
Pruning Flowering Shrubs
With such an early start to spring this year, we may have a better chance to prune spring flowering shrubs before our lives become really hectic. Many flowering shrubs — such as forsythia, spirea, weigela, and viburnum — produce canes from the base. In addition to shaping and shortening-back at the top of the shrub, consider thinning out up to one-third of the canes stemming from the base to keep the growth vigorous and floriferous.
Crossing or rubbing branches are continuously produced by normal growth; rectify them at any time. Prune the above-mentioned shrubs, and others that bloom before June 30, as soon as flowering is over. Prune those that bloom after June 30 in winter or in early spring.
With the many garden-related tasks necessary at this time of year, it is easy to overlook houseplants, those faithful winter companions left in the shadows by the glories of spring. I like to take mine outdoors for the summer and let real rain-wash cleanse their leaves and real light spark their cells. For their service and good performance, it is a fitting time to repot — and repay — them.
Over time, soil-less mixes deteriorate and lose their sponge-like ability to hold moisture and simultaneously drain well; or unwelcome insects may take up residence in the root ball. Score impacted root balls lightly with pruners or a knife to loosen, and repot one size up. Alternatively, root prune with a knife, by slicing off roots evenly around the root ball; replant in the same pot, washed, with quality potting medium appropriate to the plant.