General Conditions: Hanson received 0.7 inches of rain this past week and soils are dry. Weather was sunny, windy and on the cool side (50’s daytime). Cooler weather has slowed plant development, so plants like Magnolia stellata, Magnolia kobus var. loebneri 'Leonard Messel, Magnolia 'Wada's Memory’ and Lonicera fragrantissima (winter honeysuckle) remain in bloom. After the initial freeze a few weeks ago which damaged some of the emerging magnolia buds, in many areas the remaining undamaged buds were plentiful enough to open and continue to provide color and interest. Depending on location, PJM Rhododendrons are in full bloom, or not, depending on bud damage due to the previous cold weather in February and April. On many plants, bud damage was severe and flowering is “hit or miss”. Sugar maple, Norway maple, Prunus sp. (cherries), Lindera benzoin (Common Spicebush), Chaenomeles speciosa (Common Floweringquince), Vaccinium corymbosum (highbush blueberry), Forsythia, Pieris japonica, Pieris floribunda, Pieris 'Brouwer's Beauty', Spiraea thunbergii 'Ogon', Anemones, Primula, daffodils, hyacinths, Chionodoxa luciliae, Dicentra cucullaria (Dutchman's Breeches), Pachysandra terminalis, Pachysandra procumbens, Helleborus foetidus, H. x hybridus, Corydalis solida, Trillium, Phlox subulata, Ranunculus ficaria and Vinca minor are in full bloom. Epimedium sp., Lamium, Lunaria sp., Lathyrus vernus, Pulmonaria, Epimedium sp., Brunnera macrophylla and Ajuga are beginning to bloom and Petasites japonicus (Japanese butterbur) is ending bloom.
Pests/Problems: Although we had a warm winter and thought, perhaps, that winter moth would complete hatch earlier than usual, in fact the cold in April pushed-back winter moth development, resulting in a hatch that began April 1st in Hanson, MA and is concluding just now, April 20th. Base 40 growing degree days are at 290. There are still a few eggs hatching, but for the most part, winter moth eggs have just about finished hatching. Most of the caterpillars are 1stt instar but some are 2nd instar. Caterpillars were found in the developing buds of: blueberry, crabapple, apple, European beech, maples (Japanese, red, Norway) and feeding on the flower buds of lilac ‘James MacFarlane’. The most winter moth caterpillars I observed today were in Japanese maples. Staff at Dr. Elkinton’s lab has seen high numbers of caterpillars on buds sampled in West Bridgewater and report that for now it seems that the “cold snap may have had no impact” on winter moth numbers. However, as usual, that could change as the season progresses. Stay tuned, as we continue to get updates from Dr. Elkinton’s lab. For now, continue to monitor for winter moth caterpillars on susceptible species, especially in those areas with a heavy winter moth flight last fall and manage early to avoid extensive damage .(See Tawny Simisky’s Insect Section of the Landscape Message). Snowball aphids are active now on viburnum; their feeding causes the foliage to twist and curl, but does no significant damage. Monitor for the bright red lily leaf beetle and manage when seen. This pest of true lilies can destroy the plants unless managed. Monitor for eastern tent caterpillar on crabapples, apples and wild cherry. Monitor for spruce spider mite on spruce, fir, hemlock, arborvitae, etc. Although there was high mortality of hemlock woolly adelgid (HWA) this past winter, continue to monitor hemlocks for this pest and manage if needed. Black flies, carpenter bees, bumblebees, honeybees, solitary bees and deer ticks are active. Ground ivy is starting to bloom and violets, dandelions and chickweed are in full bloom. Bittercress continues to form seed heads. Rabbits and turkeys continue to browse. Vole damage to Hosta, Epimedium and other perennials continues to show up. White cabbage butterflies and blue, azurea butterflies were observed this week flitting about the gardens. Nice.