Monthly Tips – April

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Mercer County Horticultural Activities and Expectations

Click a month button above to view a list of possible problems you might find in your home, landscape or garden during that month and also see a list of suggested “To Do” items:

Things to Do This Month:

  • Plant roses
  • prune roses as soon as buds begin to push or when forsythia is in full bloom
  • Turf
    • fertilize lawn, if necessary
    • preemerge crabgrass control (to Apr. 15)
    • reseed small damaged lawn areas
    • apply lime if necessary
    • apply grub control only if necessary
    • resume mowing
  • improve soil with organic matter and pre-plant incorporation of fertilizer, lime
  • plant perennials and cold tolerant annuals
  • divide late blooming perennials
  • plant trees and shrubs
  • fertilize trees and shrubs
  • prune trees and shrubs (not spring blooming)
  • start seeds indoors
  • plant cool-season vegetables
  • apply dormant oil applications (early in the month)
  • apply lime sulfur to plants that won’t tolerate oil sprays, if needed
  • apply control for Eastern tent caterpillars
  • apply control for white pine weevil
  • apply hemlock woolly adelgid oil spray if needed (late)
  • correct winter damage
  • begin spray schedule for tree fruit

Things to Watch for This Month:

  • Lone star tick adult peak activity (into May)
  • termite reproductives
  • carpenter ant
  • white pine bark aphid (adelgid)
  • emergence from the house of over-wintering insects
  • clover mite activity
  • giant hornets (strip bark on lilac etc.)
  • spruce mite activity (late)
  • European pine sawfly larvae hatch (late)
  • red thread disease in ryegrass
  • Volutella canker of pachysandra
  • Dutchman’s breeches, Virginia bluebells in flower
  • forsythia bloom (early to mid)
  • lilac bloom
  • early tulips, daffodils bloom (first week and on)
  • Saucer and Star Magnolia bloom
  • Eastern tent caterpillar
  • wild onion growing (early)
  • Winter annual weeds in lawns and beds: hairy bittercress, common chickweed, henbit, purple deadnettle, some speedwells