General Conditions: June started off in the low 70’s then temperatures went down. It was 49 degrees at 7 AM June 3rd and the next few days were in the 50’s and 60’s with some temperatures in the 40’s at night. The weather folk reported that the first 6 days of June were 5 degrees below average for Boston. Cool weather and rain came in late on the afternoon of June 4th and continued into June 6th; Hanson received 2.25 inches of rain in that period; total for the week. High, gusty winds and downpours on the 5th caused some minor tree limbs to break and ‘slammed’ some perennials, like peonies and Baptisia, to the ground. The winds and rain also ‘whipped’ the blossoms off many trees and shrubs. Soils are moist and lawns are green.
The following plants are in bloom: Physocarpus opulifolius (Eastern Ninebark), Sinocalycanthus chinensis, Aesculus x carnea, Liriodendron tulipifera (Tuliptree), Cornus kousa, Cornus controversa, Cornus alternifolia, Cladrastis kentukea, Weigela florida, Indigofera sp., numerous Rhododendrons, numerous viburnums, Chionanthus virginicus, late lilacs like Syringa x prestoniae ‘James MacFarlane’ and Syringa ‘Miss Kim’, Clematis, Hydrangea anomala petiolaris, Wisteria floribunda (Japanese Wisteria), Robinia hispida (bristly locust), Calycanthus floridus (Common Sweetshrub), Beautybush, Lonicera sempervirens, Lonicera ‘John Clayton’, Clematis sp., Stephanandra incisa ‘Crispa’, Aristolochia durior (Dutchman's pipe), Alchemilla mollis, Thalictrum aquilegifolium, Anemone canadensis, Geranium sp., Persicaria bistorta 'Superbum', Doronicum, Amsonia sp., Siberian Iris, Bearded Iris, Foxgloves, Allium, Nepeta sp., Salvia 'May Night', Baptisia australis, Dianthus sp., Tradescantia, Lupines, Aquilegia (Columbine), Oriental poppies, Corydalis lutea, Arisaema (Jack-in-the-pulpit), Cypripedium sp. (Lady's Slipper). Cotinus coggygria (Smokebush) and Cotinus obovatus (American Smoketree) continue in full bloom with small greenish flowers and soon the ‘smoke’ will appear!
Styrax obassia, Rutgers hybrid dogwoods (Stellar series), Prunus serotina (black cherry), Laburnum watereri (Goldenchain Tree), Abelia mosanensisand Buglossoides purpurocaerulea are ending bloom.
Hanson is at 965 GDD - Growing Degree days, Base 40.
Pests/Problems: Winter moth caterpillars have finished feeding and have pupated. Damage from this year’s caterpillars appears to be significantly down in most areas. A probable reason for the 2017 reduced number of winter moth caterpillars can be traced back to the cold, freezing weather the first few days of April 2016, just as the winter moth eggs began to hatch. This cold wet, freezing rain and snow came in and killed many of the newly hatched exposed caterpillars, reducing their numbers dramatically and resulting in fewer caterpillars pupating and then fewer adult moths emerging in November to lay eggs for the 2017 hatch.
Gypsy moth caterpillars remain numerous and were observed in 3rd and mostly 4th instars. They were found feeding on a wide range of plant material (apples, crabapples, maples, Fothergilla, Hamamelis, etc), but the largest numbers were found feeding heavily on oak. They were also found feeding on plants, like small white pines, in the understory of oak. According to staff from Dr. Joe Elkinton’s UMass lab, many understory small pines in Wompatuck State Park, Hingham, MA, have been completely defoliated. Gypsy moth frass (feces) can be heard dropping through the trees as they feed. This sound will continue as the gypsy moth caterpillars continue to feed and grow larger over the next few weeks. owever, there may be some relief. The cool, wet weather has been conducive to the caterpillar-killing fungus, Entomophaga maimaiga, and many dead, fungus-killed caterpillars were seen hanging down on oak and pine foliage; staff from Dr. Elkinton’s lab are predicting that these numbers will increase.
Monitor perennials and if you see numerous, small, round, brown-black spots coalescing on the foliage, it could be the damage from the feeding of four-lined plant bug nymphs (orange-red with black coloration), which are active. Nymphs and adults (gold-green, with 4 longitudinal black stripes) have piercing-sucking mouthparts and the resulting damage often resembles a leaf spot disease.
Clients may be seeing native white-spotted pine sawyer and thinking it is the Asian Longhorned Beetle, but it is just one of the many Asian Longhorned Beetle (ALB) look-alikes”. http://massnrc.org/pests/albdocs/ALBLookalikes_Massachusetts.pdf
Lacebugs remain active and will be active for a long time. Monitor the undersides of foliage of Pieris, Rhododendron and azaleas for lacebug and manage if found.
Euonymus sawflylarvae (cream-colored larvae with black spots), remain active and the webs at, or near, the ends of branches are growing larger. Manage as needed and remember that Bacillus thuringiensis (Bt) does not work on sawfly larvae.
Roseslug sawfly remains active and will skeletonize rose plant foliage if not managed.
Azalea sawfly is done feeding for the year.
Continue to monitor Taxus and Meserve hollies for cottony camellia scale (also known as Cottony Taxus Scale) and manage as needed
The small white maggot of the Orthacheta Bud Fly (Iris bud fly) remains active. Remove and destroy the newly damaged flowers and stems.
The following insects remain active: mosquitoes, earwigs, lily leaf beetles, elongate hemlock scale, aphids, hemlock woolly adelgid, spruce spider mites, spittlebugs, deer tick nymphs, dog ticks, biting flies, carpenter ants, azalea whitefly, snails, woolly beech aphid, ants, wasps, hornets, carpenter bees, and bumblebees.
Beneficial insects like ladybugs (adults and larvae) and six-spotted green tiger beetles are also active.
Foliar diseases continue to make their appearance: Sycamore anthracnose is prevalent on Sycamore and foliage is very slow to appear; anthracnose is also showing up on maples and dogwood; apple scab on crabapples and apples;Phyllosticta hamamelidis (Witchhazel blight) is very noticeable on the foliage of ‘Arnold Promise’ witchhazel; Monilinia (brown rot) on Kwanzan cherry; botrytis blight on peonies. Shiny green galls of the fungal disease, Azalea leaf gall (Exobasidium vaccinii) continue to show up on deciduous azaleas; hand-pick and destroy the galls before they turn white.
While scouting for this Landscape Message, it was sad to see so many Eastern white pines with thinning canopies and brown needles. See the White Pine Needle Damage Report, in the Disease section if the May 12, 2017 Landscape Message.
The following weeds are in bloom: Multiflora rose (Massachusetts invasive plant); oxeye daisy; black swallowwort (Invasive); hawkweed; buttercup; veronica. Clearweed has sprouted; if found, weed it out with all the other weeds and apply mulch, before the weeds become large, flower and produce more seed.
White pine pollen was falling heavily before all the rain and the rain helped clean off plants, cars, etc. More pollen is expected to fall.