General Conditions: A beautiful and colorful 2017 spring; one of the best in years! The cooler weather, combined with a near-record warm day of 81 degrees on April 29, and sufficient rain, has resulted in an extended and overlapping spring bloom. Leonard Messel Magnolia just ended bloom and Forsythia remains in bloom in some areas and is just ending bloom in others, after two weeks of full bloom! Hanson received 0.72 inches of rain and soils are moist. The crabapple and apple bloom is terrific; best at one site in Hanson in15 years, mostly due to the low number of winter moth caterpillars which have decimated the flowers for so long. The crabapple fragrance is unbelievable and the honeybees are numerous and buzzing.
The following plants are in full bloom: Sassafras albidum, Magnolia ‘Elizabeth’, Malus sp. (Apples & Crabapples), Cornus florida (Flowering dogwood), Cercis canadensis, Kwanzan Cherry, Amelanchier (shadbush), Halesia sp., Prunus serotina (Black Cherry), Rhododendron ‘Olga Mezitt’, PJM Rhododendron, Chaenomeles speciosa (Common Floweringquince), Pieris floribunda (Mountain Pieris), Syringa vulgaris (Common Lilac), Spiraea prunifolia f. simplicifolia (Bridlewreath Spirea), Spiraea thunbergii ‘Ogon’, Azalea ‘April Snow’, Exochorda racemosa (Pearlbush), Rhododendron schlippenbachii (Royal Azalea), Kerria, Viburnum 'Mohawk', Viburnum carlesii (Mayflower Viburnum), Flowering Almond, Exochorda racemosa, Saruma henryi, Epimedium sp., Helleborus foetidus, Glaucidium palmatum, Vinca, Pulmonaria, Trillium, Anemones, Lamium, Primula, Brunnera macrophylla, Ajuga, Lunaria, Erythronium americanum (Trout Lily), Stylophorum diphyllum (Wood Poppy), Aurinia saxatilis (Basket of Gold), Dicentra cucullaria (Dutchman’s Breeches), Dicentra spectabilis (Bleeding Heart), Euphorbia polychroma, Asarum canadense, Phlox subulata, Arisaema sp. (Jack-in-the-pulpit), Lamiastrum galeobdolon, Lunaria annua (honesty or money plant), Mertensia virginica (Virginia bluebells), Violets, grape hyacinths, daffodils and tulips.
The following plants are beginning bloom: Fothergilla major (large Fothergilla), Fothergilla gardenii (dwarf Fothergilla), Vaccinium corymbosum (highbush blueberry), Daphne x burkwoodii 'Carol Mackie', Daphne tangutica, Meserve hybrid hollies, Convallaria majalis (Lily-of-the-valley), Phlox divaricata, Polygonatum sp. (Solomon's Seal), Tiarella cordifolia (Foam Flower) and Galium odoratum (Sweet Woodruff).
Cherry 'Hally Jolivette', Pieris 'Brouwer's Beauty', Pieris japonica, Star magnolia, Pachysandra terminalis, Sanguinaria canadensis ‘Multiplex’ (Double Bloodroot) and Helleborus x hybridus are ending bloom.
With sufficient rain, lawns are greening up nicely and with Forsythia bloom almost at the end, we are the tail end of the window for preemergence crabgrass applications. Also, if using a preventative grub management product that contains chlorantraniliprole (AceleprynTM, GrubExTM), it is best applied before the end of May; follow the directions on the label before applying.
Hummingbirds were observed in Hanson, MA on April 28th and Kingston, MA on May 1st.
Pests/Problems: Winter moth had an extended egg hatch over 2 weeks, ending April 27th, in Hanson. Scouting the landscape in the Hanson area and from reports coming in from Carver, MA, the winter moth caterpillar population appears to be down significantly from previous years. The small green winter moth caterpillars were seen feeding between the tips of leaves they have webbed together in host plants, especially Japanese maples, crabapples, apples, roses, etc. We are seeing 1st, 2nd and 3rd instar, with the majority at 2nd and 3rd instar. Hanson has 469 GDD at Base 40.
In Hingham MA, Gypsy moth began to hatch around April 26 and in Hanson around April 29, and hatch continues in each of those areas. The earlier hatched gypsy moth caterpillars have started to balloon (spin silk and float through the air) and have settled in to feed. However, with the incredible number of gypsy moth caterpillars out there that have just hatched, or are about to hatch, we should see ballooning increase this coming week. The small black caterpillars are covered with tiny hairs which are capable of causing an allergic skin reaction or rash for some people. In past years, many people reported contracting a skin rash after the gypsy moth caterpillars landed on bare skin. Examining oak buds and newly expanded oak leaves revealed both gypsy moth caterpillars and winter moth caterpillars; however, the gypsy moth caterpillars greatly outnumbered the winter moth caterpillars. Gypsy moth caterpillars were also found on blueberry flowers and buds, European beech, maples etc. Winter moth caterpillars and gypsy moth caterpillars are small right now, and damage is not yet significant. However, as the caterpillars feed, they will continue to grow in size. So, continue to monitor host trees and smaller plants, and if these caterpillars are found, manage them while they are small before too much damage is done. (See Tawny Simisky’s Insect section of the Landscape Message).
The recent rain has been beneficial not only for plants but also for the Entomophaga maimaiga fungus that inoculates gypsy moth caterpillars and kills them. We need more rain to continue to encourage the Entomophaga maimaiga fungus to hopefully knock back this substantial 2017 gypsy moth caterpillar population. Lily leaf beetles were observed in Hanson on April 27th. Both males and females are present and egg-laying has started. These bright red beetles are easy to see; manage early to avoid significant damage to true lilies. Continue to monitor hemlocks for hemlock wooly adelgid and also for elongate hemlock scale (Fiorinia externa). Elongate hemlock scale (Fiorinia externa) is also a pest on fir (Abies spp.) and spruce (Picea spp.) https://ag.umass.edu/home-lawn-garden/fact-sheets/elongate-hemlock-scale
Continue to monitor for hard-needled pines for European pine sawfly and manage early if found. Bacillus thuringiensis (Bt) does not work on sawfly larvae.
Monitor pines for pine needle scale: https://ag.umass.edu/landscape/fact-sheets/pine-needle-scale
Continue to monitor spruce, fir, hemlock, arborvitae, etc. for spruce spider mite. The following insects are active: snowball aphids on viburnum, aphids, deer ticks, dog ticks, wasps, carpenter bees, bumblebees, ants, honeybees, solitary bee, boxelder bugs and slugs.
Continue to take precautions for deer ticks, use tick repellents and conduct deer tick checks frequently. Dandelion, veronica, ground ivy, violet, and chickweed are in bloom. The Massachusetts invasive plant, barberry is also in bloom; shear back now to remove the flowers to prevent seed from forming.