University of Vermont Extension
Department of Plant and Soil Science
STAKING PEONIES AND OTHER MAY GARDENING TIPS
Charlie Nardozzi, Horticulturist and
Leonard Perry, UVM Extension Horticulturist
Staking peonies, dividing and relocating daffodils if needed, and
fertilizing perennial tulips are some of the gardening activities
for this month.
Set up supports for peonies now while plants are just emerging, so
their large flower heads don't bend to the ground next month.
Circular flower rings with legs that stick into the soil are one
option, but often the stems will bend where they droop and fall over
the ring. Stakes encircled with twine around a plant is another
option. The best support is afforded by wire mesh such as chicken
wire with large holes (2-inch mesh is good). Spread it horizontally
over the tops of the plants and attach it to some type of stakes at
the sides. The flower stems and foliage will grow up through the
mesh and hide it.
Daffodils and other spring-blooming bulbs need their foliage to
replenish the bulbs for next year's flowers, yet sometimes you might
want to relocate them after they flower but before the foliage
yellows and dies. You can move them after blooming to a new spot,
just keep the foliage, bulb, and roots intact. Keep watering and
give them a dose of fertilizer.
Many hybrid tulip bulbs propagate themselves by splitting into many
smaller bulbs after blooming. The mother bulbs will usually not
bloom again and the babies are too small to bloom yet, so these
tulips are best treated as annuals. "Perennial" tulips -- Darwin
tulips and Emperor tulips -- on the other hand, don't split so they
will bloom for a number of years. Give them a dose of bulb
fertilizer after blooming and cut off the flower stalks. Leave the
foliage intact until it dies.
Ground covers such as vinca, ajuga, pachysandra, creeping
foamflowers, lamium, and ivy can be divided and transplanted now to
create new beds or enlarge existing ones. On a cloudy, cool day, use
a sharp shovel or trowel to separate offshoots from mother plants
and transplant them into a shady new location. Keep them well
If you're seeing red over those devastating red beetles on your
lilies, it's time to get your squishing fingers loosened up. Lily
leaf beetles often show up first in spring on leaves of the crown
imperial (Fritillaria). Check both sides of the leaves and
down inside the center whorl of leaves. Also check the undersides of
leaves for tiny orange eggs. The larvae have orange, brown, or
greenish yellow bodies that are sometimes hidden under their
excrement. The botanical insecticide Neem is reported to kill the
larvae and repel the adults. For best control, spray every 5 to 7
days after the eggs hatch. Some people also report success with
spraying a lightweight dormant oil on the foliage to kill the eggs
Clear grass and weeds from root zone areas around tree trunks, and
remove any suckers growing from the base of the trees such as apples
and crabapples. Spread compost, and top with 3 to 4 inches of bark
mulch. Keep mulch an inch or two away from the trunks. Remove any
tree wraps or guards you placed on young trunks for winter
If you’re planning to grow some warm-season crops like melons or
sweet potatoes, don’t plant out until the ground has warmed to 65 to
70 degrees (F). Otherwise, plants won’t grow and may just rot.
Spread black plastic on the soil 2 to 3 weeks prior to planting to
help warm the soil more quickly. You can start such crops in pots
indoors in a sunny spot where warmer, a couple weeks before planting
out, to get a jump on their season.
(Charlie Nardozzi is a nationally known horticulturist,
author, gardening consultant, and garden coach; CharlieNardozzi.com).